df57f38a0d
40339 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Kumar Kartikeya Dwivedi
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df57f38a0d |
bpf: Permit NULL checking pointer with non-zero fixed offset
Pointer increment on seeing PTR_MAYBE_NULL is already protected against,
hence make an exception for PTR_TO_BTF_ID | MEM_ALLOC while still
keeping the warning for other unintended cases that might creep in.
bpf_list_pop_{front,_back} helpers planned to be introduced in next
commit will return a MEM_ALLOC register with incremented offset pointing
to bpf_list_node field. The user is supposed to then obtain the pointer
to the entry using container_of after NULL checking it. The current
restrictions trigger a warning when doing the NULL checking. Revisiting
the reason, it is meant as an assertion which seems to actually work and
catch the bad case.
Hence, under no other circumstances can reg->off be non-zero for a
register that has the PTR_MAYBE_NULL type flag set.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221118015614.2013203-16-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Kumar Kartikeya Dwivedi
|
ac9f06050a |
bpf: Introduce bpf_obj_drop
Introduce bpf_obj_drop, which is the kfunc used to free allocated
objects (allocated using bpf_obj_new). Pairing with bpf_obj_new, it
implicitly destructs the fields part of object automatically without
user intervention.
Just like the previous patch, btf_struct_meta that is needed to free up
the special fields is passed as a hidden argument to the kfunc.
For the user, a convenience macro hides over the kernel side kfunc which
is named bpf_obj_drop_impl.
Continuing the previous example:
void prog(void) {
struct foo *f;
f = bpf_obj_new(typeof(*f));
if (!f)
return;
bpf_obj_drop(f);
}
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221118015614.2013203-15-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Kumar Kartikeya Dwivedi
|
958cf2e273 |
bpf: Introduce bpf_obj_new
Introduce type safe memory allocator bpf_obj_new for BPF programs. The
kernel side kfunc is named bpf_obj_new_impl, as passing hidden arguments
to kfuncs still requires having them in prototype, unlike BPF helpers
which always take 5 arguments and have them checked using bpf_func_proto
in verifier, ignoring unset argument types.
Introduce __ign suffix to ignore a specific kfunc argument during type
checks, then use this to introduce support for passing type metadata to
the bpf_obj_new_impl kfunc.
The user passes BTF ID of the type it wants to allocates in program BTF,
the verifier then rewrites the first argument as the size of this type,
after performing some sanity checks (to ensure it exists and it is a
struct type).
The second argument is also fixed up and passed by the verifier. This is
the btf_struct_meta for the type being allocated. It would be needed
mostly for the offset array which is required for zero initializing
special fields while leaving the rest of storage in unitialized state.
It would also be needed in the next patch to perform proper destruction
of the object's special fields.
Under the hood, bpf_obj_new will call bpf_mem_alloc and bpf_mem_free,
using the any context BPF memory allocator introduced recently. To this
end, a global instance of the BPF memory allocator is initialized on
boot to be used for this purpose. This 'bpf_global_ma' serves all
allocations for bpf_obj_new. In the future, bpf_obj_new variants will
allow specifying a custom allocator.
Note that now that bpf_obj_new can be used to allocate objects that can
be linked to BPF linked list (when future linked list helpers are
available), we need to also free the elements using bpf_mem_free.
However, since the draining of elements is done outside the
bpf_spin_lock, we need to do migrate_disable around the call since
bpf_list_head_free can be called from map free path where migration is
enabled. Otherwise, when called from BPF programs migration is already
disabled.
A convenience macro is included in the bpf_experimental.h header to hide
over the ugly details of the implementation, leading to user code
looking similar to a language level extension which allocates and
constructs fields of a user type.
struct bar {
struct bpf_list_node node;
};
struct foo {
struct bpf_spin_lock lock;
struct bpf_list_head head __contains(bar, node);
};
void prog(void) {
struct foo *f;
f = bpf_obj_new(typeof(*f));
if (!f)
return;
...
}
A key piece of this story is still missing, i.e. the free function,
which will come in the next patch.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221118015614.2013203-14-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Kumar Kartikeya Dwivedi
|
a50388dbb3 |
bpf: Support constant scalar arguments for kfuncs
Allow passing known constant scalars as arguments to kfuncs that do not represent a size parameter. We use mark_chain_precision for the constant scalar argument to mark it precise. This makes the search pruning optimization of verifier more conservative for such kfunc calls, and each non-distinct argument is considered unequivalent. We will use this support to then expose a bpf_obj_new function where it takes the local type ID of a type in program BTF, and returns a PTR_TO_BTF_ID | MEM_ALLOC to the local type, and allows programs to allocate their own objects. Each type ID resolves to a distinct type with a possibly distinct size, hence the type ID constant matters in terms of program safety and its precision needs to be checked between old and cur states inside regsafe. The use of mark_chain_precision enables this. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221118015614.2013203-13-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
|
00b85860fe |
bpf: Rewrite kfunc argument handling
As we continue to add more features, argument types, kfunc flags, and different extensions to kfuncs, the code to verify the correctness of the kfunc prototype wrt the passed in registers has become ad-hoc and ugly to read. To make life easier, and make a very clear split between different stages of argument processing, move all the code into verifier.c and refactor into easier to read helpers and functions. This also makes sharing code within the verifier easier with kfunc argument processing. This will be more and more useful in later patches as we are now moving to implement very core BPF helpers as kfuncs, to keep them experimental before baking into UAPI. Remove all kfunc related bits now from btf_check_func_arg_match, as users have been converted away to refactored kfunc argument handling. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221118015614.2013203-12-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
|
b7ff97925b |
bpf: Allow locking bpf_spin_lock in inner map values
There is no need to restrict users from locking bpf_spin_lock in map values of inner maps. Each inner map lookup gets a unique reg->id assigned to the returned PTR_TO_MAP_VALUE which will be preserved after the NULL check. Distinct lookups into different inner map get unique IDs, and distinct lookups into same inner map also get unique IDs. Hence, lift the restriction by removing the check return -ENOTSUPP in map_in_map.c. Later commits will add comprehensive test cases to ensure that invalid cases are rejected. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221118015614.2013203-11-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
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d0d78c1df9 |
bpf: Allow locking bpf_spin_lock global variables
Global variables reside in maps accessible using direct_value_addr
callbacks, so giving each load instruction's rewrite a unique reg->id
disallows us from holding locks which are global.
The reason for preserving reg->id as a unique value for registers that
may point to spin lock is that two separate lookups are treated as two
separate memory regions, and any possible aliasing is ignored for the
purposes of spin lock correctness.
This is not great especially for the global variable case, which are
served from maps that have max_entries == 1, i.e. they always lead to
map values pointing into the same map value.
So refactor the active_spin_lock into a 'active_lock' structure which
represents the lock identity, and instead of the reg->id, remember two
fields, a pointer and the reg->id. The pointer will store reg->map_ptr
or reg->btf. It's only necessary to distinguish for the id == 0 case of
global variables, but always setting the pointer to a non-NULL value and
using the pointer to check whether the lock is held simplifies code in
the verifier.
This is generic enough to allow it for global variables, map lookups,
and allocated objects at the same time.
Note that while whether a lock is held can be answered by just comparing
active_lock.ptr to NULL, to determine whether the register is pointing
to the same held lock requires comparing _both_ ptr and id.
Finally, as a result of this refactoring, pseudo load instructions are
not given a unique reg->id, as they are doing lookup for the same map
value (max_entries is never greater than 1).
Essentially, we consider that the tuple of (ptr, id) will always be
unique for any kind of argument to bpf_spin_{lock,unlock}.
Note that this can be extended in the future to also remember offset
used for locking, so that we can introduce multiple bpf_spin_lock fields
in the same allocation.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221118015614.2013203-10-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Kumar Kartikeya Dwivedi
|
4e814da0d5 |
bpf: Allow locking bpf_spin_lock in allocated objects
Allow locking a bpf_spin_lock in an allocated object, in addition to already supported map value pointers. The handling is similar to that of map values, by just preserving the reg->id of PTR_TO_BTF_ID | MEM_ALLOC as well, and adjusting process_spin_lock to work with them and remember the id in verifier state. Refactor the existing process_spin_lock to work with PTR_TO_BTF_ID | MEM_ALLOC in addition to PTR_TO_MAP_VALUE. We need to update the reg_may_point_to_spin_lock which is used in mark_ptr_or_null_reg to preserve reg->id, that will be used in env->cur_state->active_spin_lock to remember the currently held spin lock. Also update the comment describing bpf_spin_lock implementation details to also talk about PTR_TO_BTF_ID | MEM_ALLOC type. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221118015614.2013203-9-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
|
865ce09a49 |
bpf: Verify ownership relationships for user BTF types
Ensure that there can be no ownership cycles among different types by way of having owning objects that can hold some other type as their element. For instance, a map value can only hold allocated objects, but these are allowed to have another bpf_list_head. To prevent unbounded recursion while freeing resources, elements of bpf_list_head in local kptrs can never have a bpf_list_head which are part of list in a map value. Later patches will verify this by having dedicated BTF selftests. Also, to make runtime destruction easier, once btf_struct_metas is fully populated, we can stash the metadata of the value type directly in the metadata of the list_head fields, as that allows easier access to the value type's layout to destruct it at runtime from the btf_field entry of the list head itself. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221118015614.2013203-8-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
|
8ffa5cc142 |
bpf: Recognize lock and list fields in allocated objects
Allow specifying bpf_spin_lock, bpf_list_head, bpf_list_node fields in a
allocated object.
Also update btf_struct_access to reject direct access to these special
fields.
A bpf_list_head allows implementing map-in-map style use cases, where an
allocated object with bpf_list_head is linked into a list in a map
value. This would require embedding a bpf_list_node, support for which
is also included. The bpf_spin_lock is used to protect the bpf_list_head
and other data.
While we strictly don't require to hold a bpf_spin_lock while touching
the bpf_list_head in such objects, as when have access to it, we have
complete ownership of the object, the locking constraint is still kept
and may be conditionally lifted in the future.
Note that the specification of such types can be done just like map
values, e.g.:
struct bar {
struct bpf_list_node node;
};
struct foo {
struct bpf_spin_lock lock;
struct bpf_list_head head __contains(bar, node);
struct bpf_list_node node;
};
struct map_value {
struct bpf_spin_lock lock;
struct bpf_list_head head __contains(foo, node);
};
To recognize such types in user BTF, we build a btf_struct_metas array
of metadata items corresponding to each BTF ID. This is done once during
the btf_parse stage to avoid having to do it each time during the
verification process's requirement to inspect the metadata.
Moreover, the computed metadata needs to be passed to some helpers in
future patches which requires allocating them and storing them in the
BTF that is pinned by the program itself, so that valid access can be
assumed to such data during program runtime.
A key thing to note is that once a btf_struct_meta is available for a
type, both the btf_record and btf_field_offs should be available. It is
critical that btf_field_offs is available in case special fields are
present, as we extensively rely on special fields being zeroed out in
map values and allocated objects in later patches. The code ensures that
by bailing out in case of errors and ensuring both are available
together. If the record is not available, the special fields won't be
recognized, so not having both is also fine (in terms of being a
verification error and not a runtime bug).
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221118015614.2013203-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Kumar Kartikeya Dwivedi
|
282de143ea |
bpf: Introduce allocated objects support
Introduce support for representing pointers to objects allocated by the BPF program, i.e. PTR_TO_BTF_ID that point to a type in program BTF. This is indicated by the presence of MEM_ALLOC type flag in reg->type to avoid having to check btf_is_kernel when trying to match argument types in helpers. Whenever walking such types, any pointers being walked will always yield a SCALAR instead of pointer. In the future we might permit kptr inside such allocated objects (either kernel or program allocated), and it will then form a PTR_TO_BTF_ID of the respective type. For now, such allocated objects will always be referenced in verifier context, hence ref_obj_id == 0 for them is a bug. It is allowed to write to such objects, as long fields that are special are not touched (support for which will be added in subsequent patches). Note that once such a pointer is marked PTR_UNTRUSTED, it is no longer allowed to write to it. No PROBE_MEM handling is therefore done for loads into this type unless PTR_UNTRUSTED is part of the register type, since they can never be in an undefined state, and their lifetime will always be valid. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221118015614.2013203-6-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
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f73e601aaf |
bpf: Populate field_offs for inner_map_meta
Far too much code simply assumes that both btf_record and btf_field_offs are set to valid pointers together, or both are unset. They go together hand in hand as btf_record describes the special fields and btf_field_offs is compact representation for runtime copying/zeroing. It is very difficult to make this clear in the code when the only exception to this universal invariant is inner_map_meta which is used as reg->map_ptr in the verifier. This is simply a bug waiting to happen, as in verifier context we cannot easily distinguish if PTR_TO_MAP_VALUE is coming from an inner map, and if we ever end up using field_offs for any reason in the future, we will silently ignore the special fields for inner map case (as NULL is not an error but unset field_offs). Hence, simply copy field_offs from inner map together with btf_record. While at it, refactor code to unwind properly on errors with gotos. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221118015614.2013203-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
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d48995723c |
bpf: Free inner_map_meta when btf_record_dup fails
Whenever btf_record_dup fails, we must free inner_map_meta that was
allocated before.
This fixes a memory leak (in case of errors) during inner map creation.
Fixes:
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Kumar Kartikeya Dwivedi
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d7f5ef653c |
bpf: Do btf_record_free outside map_free callback
Since the commit being fixed, we now miss freeing btf_record for local
storage maps which will have a btf_record populated in case they have
bpf_spin_lock element.
This was missed because I made the choice of offloading the job to free
kptr_off_tab (now btf_record) to the map_free callback when adding
support for kptrs.
Revisiting the reason for this decision, there is the possibility that
the btf_record gets used inside map_free callback (e.g. in case of maps
embedding kptrs) to iterate over them and free them, hence doing it
before the map_free callback would be leaking special field memory, and
do invalid memory access. The btf_record keeps module references which
is critical to ensure the dtor call made for referenced kptr is safe to
do.
If doing it after map_free callback, the map area is already freed, so
we cannot access bpf_map structure anymore.
To fix this and prevent such lapses in future, move bpf_map_free_record
out of the map_free callback, and do it after map_free by remembering
the btf_record pointer. There is no need to access bpf_map structure in
that case, and we can avoid missing this case when support for new map
types is added for other special fields.
Since a btf_record and its btf_field_offs are used together, for
consistency delay freeing of field_offs as well. While not a problem
right now, a lot of code assumes that either both record and field_offs
are set or none at once.
Note that in case of map of maps (outer maps), inner_map_meta->record is
only used during verification, not to free fields in map value, hence we
simply keep the bpf_map_free_record call as is in bpf_map_meta_free and
never touch map->inner_map_meta in bpf_map_free_deferred.
Add a comment making note of these details.
Fixes:
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Kumar Kartikeya Dwivedi
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c237bfa528 |
bpf: Fix early return in map_check_btf
Instead of returning directly with -EOPNOTSUPP for the timer case, we
need to free the btf_record before returning to userspace.
Fixes:
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Hou Tao
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3af43ba4c6 |
bpf: Pass map file to .map_update_batch directly
Currently bpf_map_do_batch() first invokes fdget(batch.map_fd) to get the target map file, then it invokes generic_map_update_batch() to do batch update. generic_map_update_batch() will get the target map file by using fdget(batch.map_fd) again and pass it to bpf_map_update_value(). The problem is map file returned by the second fdget() may be NULL or a totally different file compared by map file in bpf_map_do_batch(). The reason is that the first fdget() only guarantees the liveness of struct file instead of file descriptor and the file description may be released by concurrent close() through pick_file(). It doesn't incur any problem as for now, because maps with batch update support don't use map file in .map_fd_get_ptr() ops. But it is better to fix the potential access of an invalid map file. Using __bpf_map_get() again in generic_map_update_batch() can not fix the problem, because batch.map_fd may be closed and reopened, and the returned map file may be different with map file got in bpf_map_do_batch(), so just passing the map file directly to .map_update_batch() in bpf_map_do_batch(). Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20221116075059.1551277-1-houtao@huaweicloud.com |
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Eduard Zingerman
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befae75856 |
bpf: propagate nullness information for reg to reg comparisons
Propagate nullness information for branches of register to register equality compare instructions. The following rules are used: - suppose register A maybe null - suppose register B is not null - for JNE A, B, ... - A is not null in the false branch - for JEQ A, B, ... - A is not null in the true branch E.g. for program like below: r6 = skb->sk; r7 = sk_fullsock(r6); r0 = sk_fullsock(r6); if (r0 == 0) return 0; (a) if (r0 != r7) return 0; (b) *r7->type; (c) return 0; It is safe to dereference r7 at point (c), because of (a) and (b). Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20221115224859.2452988-2-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Toke Høiland-Jørgensen
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32637e3300 |
bpf: Expand map key argument of bpf_redirect_map to u64
For queueing packets in XDP we want to add a new redirect map type with support for 64-bit indexes. To prepare fore this, expand the width of the 'key' argument to the bpf_redirect_map() helper. Since BPF registers are always 64-bit, this should be safe to do after the fact. Acked-by: Song Liu <song@kernel.org> Reviewed-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20221108140601.149971-3-toke@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
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6728aea721 |
bpf: Refactor btf_struct_access
Instead of having to pass multiple arguments that describe the register, pass the bpf_reg_state into the btf_struct_access callback. Currently, all call sites simply reuse the btf and btf_id of the reg they want to check the access of. The only exception to this pattern is the callsite in check_ptr_to_map_access, hence for that case create a dummy reg to simulate PTR_TO_BTF_ID access. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221114191547.1694267-8-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
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894f2a8b16 |
bpf: Rename MEM_ALLOC to MEM_RINGBUF
Currently, verifier uses MEM_ALLOC type tag to specially tag memory returned from bpf_ringbuf_reserve helper. However, this is currently only used for this purpose and there is an implicit assumption that it only refers to ringbuf memory (e.g. the check for ARG_PTR_TO_ALLOC_MEM in check_func_arg_reg_off). Hence, rename MEM_ALLOC to MEM_RINGBUF to indicate this special relationship and instead open the use of MEM_ALLOC for more generic allocations made for user types. Also, since ARG_PTR_TO_ALLOC_MEM_OR_NULL is unused, simply drop it. Finally, update selftests using 'alloc_' verifier string to 'ringbuf_'. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221114191547.1694267-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
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2de2669b4e |
bpf: Rename RET_PTR_TO_ALLOC_MEM
Currently, the verifier has two return types, RET_PTR_TO_ALLOC_MEM, and
RET_PTR_TO_ALLOC_MEM_OR_NULL, however the former is confusingly named to
imply that it carries MEM_ALLOC, while only the latter does. This causes
confusion during code review leading to conclusions like that the return
value of RET_PTR_TO_DYNPTR_MEM_OR_NULL (which is RET_PTR_TO_ALLOC_MEM |
PTR_MAYBE_NULL) may be consumable by bpf_ringbuf_{submit,commit}.
Rename it to make it clear MEM_ALLOC needs to be tacked on top of
RET_PTR_TO_MEM.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221114191547.1694267-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Kumar Kartikeya Dwivedi
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f0c5941ff5 |
bpf: Support bpf_list_head in map values
Add the support on the map side to parse, recognize, verify, and build
metadata table for a new special field of the type struct bpf_list_head.
To parameterize the bpf_list_head for a certain value type and the
list_node member it will accept in that value type, we use BTF
declaration tags.
The definition of bpf_list_head in a map value will be done as follows:
struct foo {
struct bpf_list_node node;
int data;
};
struct map_value {
struct bpf_list_head head __contains(foo, node);
};
Then, the bpf_list_head only allows adding to the list 'head' using the
bpf_list_node 'node' for the type struct foo.
The 'contains' annotation is a BTF declaration tag composed of four
parts, "contains:name:node" where the name is then used to look up the
type in the map BTF, with its kind hardcoded to BTF_KIND_STRUCT during
the lookup. The node defines name of the member in this type that has
the type struct bpf_list_node, which is actually used for linking into
the linked list. For now, 'kind' part is hardcoded as struct.
This allows building intrusive linked lists in BPF, using container_of
to obtain pointer to entry, while being completely type safe from the
perspective of the verifier. The verifier knows exactly the type of the
nodes, and knows that list helpers return that type at some fixed offset
where the bpf_list_node member used for this list exists. The verifier
also uses this information to disallow adding types that are not
accepted by a certain list.
For now, no elements can be added to such lists. Support for that is
coming in future patches, hence draining and freeing items is done with
a TODO that will be resolved in a future patch.
Note that the bpf_list_head_free function moves the list out to a local
variable under the lock and releases it, doing the actual draining of
the list items outside the lock. While this helps with not holding the
lock for too long pessimizing other concurrent list operations, it is
also necessary for deadlock prevention: unless every function called in
the critical section would be notrace, a fentry/fexit program could
attach and call bpf_map_update_elem again on the map, leading to the
same lock being acquired if the key matches and lead to a deadlock.
While this requires some special effort on part of the BPF programmer to
trigger and is highly unlikely to occur in practice, it is always better
if we can avoid such a condition.
While notrace would prevent this, doing the draining outside the lock
has advantages of its own, hence it is used to also fix the deadlock
related problem.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221114191547.1694267-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Kumar Kartikeya Dwivedi
|
2d57725257 |
bpf: Remove BPF_MAP_OFF_ARR_MAX
In
|
||
Jakub Kicinski
|
f4c4ca70de |
bpf-next-for-netdev
-----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEET63h6RnJhTJHuKTjXOwUVIRcSScFAmNu2EkACgkQXOwUVIRc SSebKhAA0ffmp5jJgEJpQYNABGLYIJcwKkBrGClDbMJLtwCjevGZJajT9fpbCLb1 eK6EIhdfR0NTO+0KtUVkZ8WMa81OmLEJYdTNtJfNE23ENMpssiAWhlhDF8AoXeKv Bo3j719gn3Cw9PWXQoircH3wpj+5RMDnjxy4iYlA5yNrvzC7XVmssMF+WALvQnuK CGrfR57hxdgmphmasRqeCzEoriwihwPsG3k6eQN8rf7ZytLhs90tMVgT9L3Cd2u9 DafA0Xl8mZdz2mHhThcJhQVq4MUymZj44ufuHDiOs1j6nhUlWToyQuvegPOqxKti uLGtZul0ls+3UP0Lbrv1oEGU/MWMxyDz4IBc0EVs0k3ItQbmSKs6r9WuPFGd96Sb GHk68qFVySeLGN0LfKe3rCHJ9ZoIOPYJg9qT8Rd5bOhetgGwSsxZTxUI39BxkFup CEqwIDnts1TMU37GDjj+vssKW91k4jEzMZVtRfsL3J36aJs28k/Ez4AqLXg6WU6u ADqFaejVPcXbN9rX90onIYxxiL28gZSeT+i8qOPELZtqTQmNWz+tC/ySVuWnD8Mn Nbs7PZ1IWiNZpsKS8pZnpd6j4mlBeJnwXkPKiFy+xHGuwRSRdYl6G9e5CtlRely/ rwQ8DtaOpRYMrGhnmBEdAOCa9t/iqzrzHzjoigjJ7iAST4ToJ5s= =Y+/e -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Andrii Nakryiko says: ==================== bpf-next 2022-11-11 We've added 49 non-merge commits during the last 9 day(s) which contain a total of 68 files changed, 3592 insertions(+), 1371 deletions(-). The main changes are: 1) Veristat tool improvements to support custom filtering, sorting, and replay of results, from Andrii Nakryiko. 2) BPF verifier precision tracking fixes and improvements, from Andrii Nakryiko. 3) Lots of new BPF documentation for various BPF maps, from Dave Tucker, Donald Hunter, Maryam Tahhan, Bagas Sanjaya. 4) BTF dedup improvements and libbpf's hashmap interface clean ups, from Eduard Zingerman. 5) Fix veth driver panic if XDP program is attached before veth_open, from John Fastabend. 6) BPF verifier clean ups and fixes in preparation for follow up features, from Kumar Kartikeya Dwivedi. 7) Add access to hwtstamp field from BPF sockops programs, from Martin KaFai Lau. 8) Various fixes for BPF selftests and samples, from Artem Savkov, Domenico Cerasuolo, Kang Minchul, Rong Tao, Yang Jihong. 9) Fix redirection to tunneling device logic, preventing skb->len == 0, from Stanislav Fomichev. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (49 commits) selftests/bpf: fix veristat's singular file-or-prog filter selftests/bpf: Test skops->skb_hwtstamp selftests/bpf: Fix incorrect ASSERT in the tcp_hdr_options test bpf: Add hwtstamp field for the sockops prog selftests/bpf: Fix xdp_synproxy compilation failure in 32-bit arch bpf, docs: Document BPF_MAP_TYPE_ARRAY docs/bpf: Document BPF map types QUEUE and STACK docs/bpf: Document BPF ARRAY_OF_MAPS and HASH_OF_MAPS docs/bpf: Document BPF_MAP_TYPE_CPUMAP map docs/bpf: Document BPF_MAP_TYPE_LPM_TRIE map libbpf: Hashmap.h update to fix build issues using LLVM14 bpf: veth driver panics when xdp prog attached before veth_open selftests: Fix test group SKIPPED result selftests/bpf: Tests for btf_dedup_resolve_fwds libbpf: Resolve unambigous forward declarations libbpf: Hashmap interface update to allow both long and void* keys/values samples/bpf: Fix sockex3 error: Missing BPF prog type selftests/bpf: Fix u32 variable compared with less than zero Documentation: bpf: Escape underscore in BPF type name prefix selftests/bpf: Use consistent build-id type for liburandom_read.so ... ==================== Link: https://lore.kernel.org/r/20221111233733.1088228-1-andrii@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
||
Maryam Tahhan
|
161939abc8 |
docs/bpf: Document BPF_MAP_TYPE_CPUMAP map
Add documentation for BPF_MAP_TYPE_CPUMAP including kernel version introduced, usage and examples. Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Maryam Tahhan <mtahhan@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20221107165207.2682075-2-mtahhan@redhat.com |
||
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Jakub Kicinski
|
966a9b4903 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/can/pch_can.c |
||
Linus Torvalds
|
4bbf3422df |
Including fixes from netfilter, wifi, can and bpf.
Current release - new code bugs:
- can: af_can: can_exit(): add missing dev_remove_pack() of canxl_packet
Previous releases - regressions:
- bpf, sockmap: fix the sk->sk_forward_alloc warning
- wifi: mac80211: fix general-protection-fault in
ieee80211_subif_start_xmit()
- can: af_can: fix NULL pointer dereference in can_rx_register()
- can: dev: fix skb drop check, avoid o-o-b access
- nfnetlink: fix potential dead lock in nfnetlink_rcv_msg()
Previous releases - always broken:
- bpf: fix wrong reg type conversion in release_reference()
- gso: fix panic on frag_list with mixed head alloc types
- wifi: brcmfmac: fix buffer overflow in brcmf_fweh_event_worker()
- wifi: mac80211: set TWT Information Frame Disabled bit as 1
- eth: macsec offload related fixes, make sure to clear the keys
from memory
- tun: fix memory leaks in the use of napi_get_frags
- tun: call napi_schedule_prep() to ensure we own a napi
- tcp: prohibit TCP_REPAIR_OPTIONS if data was already sent
- ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg
to network
- tipc: fix a msg->req tlv length check
- sctp: clear out_curr if all frag chunks of current msg are pruned,
avoid list corruption
- mctp: fix an error handling path in mctp_init(), avoid leaks
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-6.1-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from netfilter, wifi, can and bpf.
Current release - new code bugs:
- can: af_can: can_exit(): add missing dev_remove_pack() of
canxl_packet
Previous releases - regressions:
- bpf, sockmap: fix the sk->sk_forward_alloc warning
- wifi: mac80211: fix general-protection-fault in
ieee80211_subif_start_xmit()
- can: af_can: fix NULL pointer dereference in can_rx_register()
- can: dev: fix skb drop check, avoid o-o-b access
- nfnetlink: fix potential dead lock in nfnetlink_rcv_msg()
Previous releases - always broken:
- bpf: fix wrong reg type conversion in release_reference()
- gso: fix panic on frag_list with mixed head alloc types
- wifi: brcmfmac: fix buffer overflow in brcmf_fweh_event_worker()
- wifi: mac80211: set TWT Information Frame Disabled bit as 1
- eth: macsec offload related fixes, make sure to clear the keys from
memory
- tun: fix memory leaks in the use of napi_get_frags
- tun: call napi_schedule_prep() to ensure we own a napi
- tcp: prohibit TCP_REPAIR_OPTIONS if data was already sent
- ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to
network
- tipc: fix a msg->req tlv length check
- sctp: clear out_curr if all frag chunks of current msg are pruned,
avoid list corruption
- mctp: fix an error handling path in mctp_init(), avoid leaks"
* tag 'net-6.1-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (101 commits)
eth: sp7021: drop free_netdev() from spl2sw_init_netdev()
MAINTAINERS: Move Vivien to CREDITS
net: macvlan: fix memory leaks of macvlan_common_newlink
ethernet: tundra: free irq when alloc ring failed in tsi108_open()
net: mv643xx_eth: disable napi when init rxq or txq failed in mv643xx_eth_open()
ethernet: s2io: disable napi when start nic failed in s2io_card_up()
net: atlantic: macsec: clear encryption keys from the stack
net: phy: mscc: macsec: clear encryption keys when freeing a flow
stmmac: dwmac-loongson: fix missing of_node_put() while module exiting
stmmac: dwmac-loongson: fix missing pci_disable_device() in loongson_dwmac_probe()
stmmac: dwmac-loongson: fix missing pci_disable_msi() while module exiting
cxgb4vf: shut down the adapter when t4vf_update_port_info() failed in cxgb4vf_open()
mctp: Fix an error handling path in mctp_init()
stmmac: intel: Update PCH PTP clock rate from 200MHz to 204.8MHz
net: cxgb3_main: disable napi when bind qsets failed in cxgb_up()
net: cpsw: disable napi in cpsw_ndo_open()
iavf: Fix VF driver counting VLAN 0 filters
ice: Fix spurious interrupt during removal of trusted VF
net/mlx5e: TC, Fix slab-out-of-bounds in parse_tc_actions
net/mlx5e: E-Switch, Fix comparing termination table instance
...
|
||
|
Linus Torvalds
|
727ea09e99 |
- Add Cooper Lake's stepping to the PEBS guest/host events isolation
fixed microcode revisions checking quirk - Update Icelake and Sapphire Rapids events constraints - Use the standard energy unit for Sapphire Rapids in RAPL - Fix the hw_breakpoint test to fail more graciously on !SMP configs -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmNnr/4ACgkQEsHwGGHe VUrFRg//dyB0lnQcdvIaPd7DWn3WGop+MeZv0NZI7uYk+SqjtJ3yJ/c4ktcaIgJV MhTk8Q/gxHvuT+MZarC/f1QYtTqzRQ//rKD2aO/l9Gr813Hu4R0z2AEwrNKDmzyd BYy3O5GXGeBAiLxtmKZ2bDlS5z8a9L3dlbLCWqjq6iGIVncljWmEDmNQmA3YPury v8f+V8EqfSE4iWcpnNsZOdrmkMkXEzA8X5vRswQ9l2y6qMmnEeUk9Hn9mFlG+QK4 VDyxkQEB+vZVfWL2UjD3dpEaH5LVyfCQBwOaVdFfHhMmLhoTO2VmRMLza3Qd9ejZ RIE1hlRibqGMqyHDTjZvnkPgnz4QQqayDf8UIIwVdaMVdIaZmxcIQwfsbQS12E5b 9EBzbaD6TJx42E56WuQHM+ZYt6nz0ktPz0IeBFJIwbU30gqJwdi0uIz2kXNpkthC eX4Bq/iM9C41A58mj9+uerF9jshi/DJU74KcMGUZiJ7IeGDJgL9CfViOTueMOjr2 OI8nvLOtwBpj8X3AO1nEVkevSt4KPoTD+NVCNpXmjVm9DNFvMRo2EUsRHHrCkLJN EO7iF14rTlSI7IAE+qxNgRsmXPCyuVBhB3S3/3YmCqsH1kQXqlgxT/2eOJN6kCGz tlaWnD3TEaifH/DQQVGmv9nNFjS0C49MSxrZ7Oe7phnmSn3vaGY= =midC -----END PGP SIGNATURE----- Merge tag 'perf_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Add Cooper Lake's stepping to the PEBS guest/host events isolation fixed microcode revisions checking quirk - Update Icelake and Sapphire Rapids events constraints - Use the standard energy unit for Sapphire Rapids in RAPL - Fix the hw_breakpoint test to fail more graciously on !SMP configs * tag 'perf_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Add Cooper Lake stepping to isolation_ucodes[] perf/x86/intel: Fix pebs event constraints for SPR perf/x86/intel: Fix pebs event constraints for ICL perf/x86/rapl: Use standard Energy Unit for SPR Dram RAPL domain perf/hw_breakpoint: test: Skip the test if dependencies unmet |
||
Andrii Nakryiko
|
7a830b53c1 |
bpf: aggressively forget precise markings during state checkpointing
Exploit the property of about-to-be-checkpointed state to be able to forget all precise markings up to that point even more aggressively. We now clear all potentially inherited precise markings right before checkpointing and branching off into child state. If any of children states require precise knowledge of any SCALAR register, those will be propagated backwards later on before this state is finalized, preserving correctness. There is a single selftests BPF program change, but tremendous one: 25x reduction in number of verified instructions and states in trace_virtqueue_add_sgs. Cilium results are more modest, but happen across wider range of programs. SELFTESTS RESULTS ================= $ ./veristat -C -e file,prog,insns,states ~/imprecise-early-results.csv ~/imprecise-aggressive-results.csv | grep -v '+0' File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF) ------------------- ----------------------- --------------- --------------- ------------------ ---------------- ---------------- ------------------- loop6.bpf.linked1.o trace_virtqueue_add_sgs 398057 15114 -382943 (-96.20%) 8717 336 -8381 (-96.15%) ------------------- ----------------------- --------------- --------------- ------------------ ---------------- ---------------- ------------------- CILIUM RESULTS ============== $ ./veristat -C -e file,prog,insns,states ~/imprecise-early-results-cilium.csv ~/imprecise-aggressive-results-cilium.csv | grep -v '+0' File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF) ------------- -------------------------------- --------------- --------------- ------------------ ---------------- ---------------- ------------------- bpf_host.o tail_handle_nat_fwd_ipv4 23426 23221 -205 (-0.88%) 1537 1515 -22 (-1.43%) bpf_host.o tail_handle_nat_fwd_ipv6 13009 12904 -105 (-0.81%) 719 708 -11 (-1.53%) bpf_host.o tail_nodeport_nat_ingress_ipv6 5261 5196 -65 (-1.24%) 247 243 -4 (-1.62%) bpf_host.o tail_nodeport_nat_ipv6_egress 3446 3406 -40 (-1.16%) 203 198 -5 (-2.46%) bpf_lxc.o tail_handle_nat_fwd_ipv4 23426 23221 -205 (-0.88%) 1537 1515 -22 (-1.43%) bpf_lxc.o tail_handle_nat_fwd_ipv6 13009 12904 -105 (-0.81%) 719 708 -11 (-1.53%) bpf_lxc.o tail_ipv4_ct_egress 5074 4897 -177 (-3.49%) 255 248 -7 (-2.75%) bpf_lxc.o tail_ipv4_ct_ingress 5100 4923 -177 (-3.47%) 255 248 -7 (-2.75%) bpf_lxc.o tail_ipv4_ct_ingress_policy_only 5100 4923 -177 (-3.47%) 255 248 -7 (-2.75%) bpf_lxc.o tail_ipv6_ct_egress 4558 4536 -22 (-0.48%) 188 187 -1 (-0.53%) bpf_lxc.o tail_ipv6_ct_ingress 4578 4556 -22 (-0.48%) 188 187 -1 (-0.53%) bpf_lxc.o tail_ipv6_ct_ingress_policy_only 4578 4556 -22 (-0.48%) 188 187 -1 (-0.53%) bpf_lxc.o tail_nodeport_nat_ingress_ipv6 5261 5196 -65 (-1.24%) 247 243 -4 (-1.62%) bpf_overlay.o tail_nodeport_nat_ingress_ipv6 5261 5196 -65 (-1.24%) 247 243 -4 (-1.62%) bpf_overlay.o tail_nodeport_nat_ipv6_egress 3482 3442 -40 (-1.15%) 204 201 -3 (-1.47%) bpf_xdp.o tail_nodeport_nat_egress_ipv4 17200 15619 -1581 (-9.19%) 1111 1010 -101 (-9.09%) ------------- -------------------------------- --------------- --------------- ------------------ ---------------- ---------------- ------------------- Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20221104163649.121784-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
f63181b6ae |
bpf: stop setting precise in current state
Setting reg->precise to true in current state is not necessary from correctness standpoint, but it does pessimise the whole precision (or rather "imprecision", because that's what we want to keep as much as possible) tracking. Why is somewhat subtle and my best attempt to explain this is recorded in an extensive comment for __mark_chain_precise() function. Some more careful thinking and code reading is probably required still to grok this completely, unfortunately. Whiteboarding and a bunch of extra handwaiving in person would be even more helpful, but is deemed impractical in Git commit. Next patch pushes this imprecision property even further, building on top of the insights described in this patch. End results are pretty nice, we get reduction in number of total instructions and states verified due to a better states reuse, as some of the states are now more generic and permissive due to less unnecessary precise=true requirements. SELFTESTS RESULTS ================= $ ./veristat -C -e file,prog,insns,states ~/subprog-precise-results.csv ~/imprecise-early-results.csv | grep -v '+0' File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF) --------------------------------------- ---------------------- --------------- --------------- ------------------ ---------------- ---------------- ------------------- bpf_iter_ksym.bpf.linked1.o dump_ksym 347 285 -62 (-17.87%) 20 19 -1 (-5.00%) pyperf600_bpf_loop.bpf.linked1.o on_event 3678 3736 +58 (+1.58%) 276 285 +9 (+3.26%) setget_sockopt.bpf.linked1.o skops_sockopt 4038 3947 -91 (-2.25%) 347 343 -4 (-1.15%) test_l4lb.bpf.linked1.o balancer_ingress 4559 2611 -1948 (-42.73%) 118 105 -13 (-11.02%) test_l4lb_noinline.bpf.linked1.o balancer_ingress 6279 6268 -11 (-0.18%) 237 236 -1 (-0.42%) test_misc_tcp_hdr_options.bpf.linked1.o misc_estab 1307 1303 -4 (-0.31%) 100 99 -1 (-1.00%) test_sk_lookup.bpf.linked1.o ctx_narrow_access 456 447 -9 (-1.97%) 39 38 -1 (-2.56%) test_sysctl_loop1.bpf.linked1.o sysctl_tcp_mem 1389 1384 -5 (-0.36%) 26 25 -1 (-3.85%) test_tc_dtime.bpf.linked1.o egress_fwdns_prio101 518 485 -33 (-6.37%) 51 46 -5 (-9.80%) test_tc_dtime.bpf.linked1.o egress_host 519 468 -51 (-9.83%) 50 44 -6 (-12.00%) test_tc_dtime.bpf.linked1.o ingress_fwdns_prio101 842 1000 +158 (+18.76%) 73 88 +15 (+20.55%) xdp_synproxy_kern.bpf.linked1.o syncookie_tc 405757 373173 -32584 (-8.03%) 25735 22882 -2853 (-11.09%) xdp_synproxy_kern.bpf.linked1.o syncookie_xdp 479055 371590 -107465 (-22.43%) 29145 22207 -6938 (-23.81%) --------------------------------------- ---------------------- --------------- --------------- ------------------ ---------------- ---------------- ------------------- Slight regression in test_tc_dtime.bpf.linked1.o/ingress_fwdns_prio101 is left for a follow up, there might be some more precision-related bugs in existing BPF verifier logic. CILIUM RESULTS ============== $ ./veristat -C -e file,prog,insns,states ~/subprog-precise-results-cilium.csv ~/imprecise-early-results-cilium.csv | grep -v '+0' File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF) ------------- ------------------------------ --------------- --------------- ------------------ ---------------- ---------------- ------------------- bpf_host.o cil_from_host 762 556 -206 (-27.03%) 43 37 -6 (-13.95%) bpf_host.o tail_handle_nat_fwd_ipv4 23541 23426 -115 (-0.49%) 1538 1537 -1 (-0.07%) bpf_host.o tail_nodeport_nat_egress_ipv4 33592 33566 -26 (-0.08%) 2163 2161 -2 (-0.09%) bpf_lxc.o tail_handle_nat_fwd_ipv4 23541 23426 -115 (-0.49%) 1538 1537 -1 (-0.07%) bpf_overlay.o tail_nodeport_nat_egress_ipv4 33581 33543 -38 (-0.11%) 2160 2157 -3 (-0.14%) bpf_xdp.o tail_handle_nat_fwd_ipv4 21659 20920 -739 (-3.41%) 1440 1376 -64 (-4.44%) bpf_xdp.o tail_handle_nat_fwd_ipv6 17084 17039 -45 (-0.26%) 907 905 -2 (-0.22%) bpf_xdp.o tail_lb_ipv4 73442 73430 -12 (-0.02%) 4370 4369 -1 (-0.02%) bpf_xdp.o tail_lb_ipv6 152114 151895 -219 (-0.14%) 6493 6479 -14 (-0.22%) bpf_xdp.o tail_nodeport_nat_egress_ipv4 17377 17200 -177 (-1.02%) 1125 1111 -14 (-1.24%) bpf_xdp.o tail_nodeport_nat_ingress_ipv6 6405 6397 -8 (-0.12%) 309 308 -1 (-0.32%) bpf_xdp.o tail_rev_nodeport_lb4 7126 6934 -192 (-2.69%) 414 402 -12 (-2.90%) bpf_xdp.o tail_rev_nodeport_lb6 18059 17905 -154 (-0.85%) 1105 1096 -9 (-0.81%) ------------- ------------------------------ --------------- --------------- ------------------ ---------------- ---------------- ------------------- Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20221104163649.121784-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
be2ef81615 |
bpf: allow precision tracking for programs with subprogs
Stop forcing precise=true for SCALAR registers when BPF program has any subprograms. Current restriction means that any BPF program, as soon as it uses subprograms, will end up not getting any of the precision tracking benefits in reduction of number of verified states. This patch keeps the fallback mark_all_scalars_precise() behavior if precise marking has to cross function frames. E.g., if subprogram requires R1 (first input arg) to be marked precise, ideally we'd need to backtrack to the parent function and keep marking R1 and its dependencies as precise. But right now we give up and force all the SCALARs in any of the current and parent states to be forced to precise=true. We can lift that restriction in the future. But this patch fixes two issues identified when trying to enable precision tracking for subprogs. First, prevent "escaping" from top-most state in a global subprog. While with entry-level BPF program we never end up requesting precision for R1-R5 registers, because R2-R5 are not initialized (and so not readable in correct BPF program), and R1 is PTR_TO_CTX, not SCALAR, and so is implicitly precise. With global subprogs, though, it's different, as global subprog a) can have up to 5 SCALAR input arguments, which might get marked as precise=true and b) it is validated in isolation from its main entry BPF program. b) means that we can end up exhausting parent state chain and still not mark all registers in reg_mask as precise, which would lead to verifier bug warning. To handle that, we need to consider two cases. First, if the very first state is not immediately "checkpointed" (i.e., stored in state lookup hashtable), it will get correct first_insn_idx and last_insn_idx instruction set during state checkpointing. As such, this case is already handled and __mark_chain_precision() already handles that by just doing nothing when we reach to the very first parent state. st->parent will be NULL and we'll just stop. Perhaps some extra check for reg_mask and stack_mask is due here, but this patch doesn't address that issue. More problematic second case is when global function's initial state is immediately checkpointed before we manage to process the very first instruction. This is happening because when there is a call to global subprog from the main program the very first subprog's instruction is marked as pruning point, so before we manage to process first instruction we have to check and checkpoint state. This patch adds a special handling for such "empty" state, which is identified by having st->last_insn_idx set to -1. In such case, we check that we are indeed validating global subprog, and with some sanity checking we mark input args as precise if requested. Note that we also initialize state->first_insn_idx with correct start insn_idx offset. For main program zero is correct value, but for any subprog it's quite confusing to not have first_insn_idx set. This doesn't have any functional impact, but helps with debugging and state printing. We also explicitly initialize state->last_insns_idx instead of relying on is_state_visited() to do this with env->prev_insns_idx, which will be -1 on the very first instruction. This concludes necessary changes to handle specifically global subprog's precision tracking. Second identified problem was missed handling of BPF helper functions that call into subprogs (e.g., bpf_loop and few others). From precision tracking and backtracking logic's standpoint those are effectively calls into subprogs and should be called as BPF_PSEUDO_CALL calls. This patch takes the least intrusive way and just checks against a short list of current BPF helpers that do call subprogs, encapsulated in is_callback_calling_function() function. But to prevent accidentally forgetting to add new BPF helpers to this "list", we also do a sanity check in __check_func_call, which has to be called for each such special BPF helper, to validate that BPF helper is indeed recognized as callback-calling one. This should catch any missed checks in the future. Adding some special flags to be added in function proto definitions seemed like an overkill in this case. With the above changes, it's possible to remove forceful setting of reg->precise to true in __mark_reg_unknown, which turns on precision tracking both inside subprogs and entry progs that have subprogs. No warnings or errors were detected across all the selftests, but also when validating with veristat against internal Meta BPF objects and Cilium objects. Further, in some BPF programs there are noticeable reduction in number of states and instructions validated due to more effective precision tracking, especially benefiting syncookie test. $ ./veristat -C -e file,prog,insns,states ~/baseline-results.csv ~/subprog-precise-results.csv | grep -v '+0' File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF) ---------------------------------------- -------------------------- --------------- --------------- ------------------ ---------------- ---------------- ------------------- pyperf600_bpf_loop.bpf.linked1.o on_event 3966 3678 -288 (-7.26%) 306 276 -30 (-9.80%) pyperf_global.bpf.linked1.o on_event 7563 7530 -33 (-0.44%) 520 517 -3 (-0.58%) pyperf_subprogs.bpf.linked1.o on_event 36358 36934 +576 (+1.58%) 2499 2531 +32 (+1.28%) setget_sockopt.bpf.linked1.o skops_sockopt 3965 4038 +73 (+1.84%) 343 347 +4 (+1.17%) test_cls_redirect_subprogs.bpf.linked1.o cls_redirect 64965 64901 -64 (-0.10%) 4619 4612 -7 (-0.15%) test_misc_tcp_hdr_options.bpf.linked1.o misc_estab 1491 1307 -184 (-12.34%) 110 100 -10 (-9.09%) test_pkt_access.bpf.linked1.o test_pkt_access 354 349 -5 (-1.41%) 25 24 -1 (-4.00%) test_sock_fields.bpf.linked1.o egress_read_sock_fields 435 375 -60 (-13.79%) 22 20 -2 (-9.09%) test_sysctl_loop2.bpf.linked1.o sysctl_tcp_mem 1508 1501 -7 (-0.46%) 29 28 -1 (-3.45%) test_tc_dtime.bpf.linked1.o egress_fwdns_prio100 468 435 -33 (-7.05%) 45 41 -4 (-8.89%) test_tc_dtime.bpf.linked1.o ingress_fwdns_prio100 398 408 +10 (+2.51%) 42 39 -3 (-7.14%) test_tc_dtime.bpf.linked1.o ingress_fwdns_prio101 1096 842 -254 (-23.18%) 97 73 -24 (-24.74%) test_tcp_hdr_options.bpf.linked1.o estab 2758 2408 -350 (-12.69%) 208 181 -27 (-12.98%) test_urandom_usdt.bpf.linked1.o urand_read_with_sema 466 448 -18 (-3.86%) 31 28 -3 (-9.68%) test_urandom_usdt.bpf.linked1.o urand_read_without_sema 466 448 -18 (-3.86%) 31 28 -3 (-9.68%) test_urandom_usdt.bpf.linked1.o urandlib_read_with_sema 466 448 -18 (-3.86%) 31 28 -3 (-9.68%) test_urandom_usdt.bpf.linked1.o urandlib_read_without_sema 466 448 -18 (-3.86%) 31 28 -3 (-9.68%) test_xdp_noinline.bpf.linked1.o balancer_ingress_v6 4302 4294 -8 (-0.19%) 257 256 -1 (-0.39%) xdp_synproxy_kern.bpf.linked1.o syncookie_tc 583722 405757 -177965 (-30.49%) 35846 25735 -10111 (-28.21%) xdp_synproxy_kern.bpf.linked1.o syncookie_xdp 609123 479055 -130068 (-21.35%) 35452 29145 -6307 (-17.79%) ---------------------------------------- -------------------------- --------------- --------------- ------------------ ---------------- ---------------- ------------------- Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20221104163649.121784-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
529409ea92 |
bpf: propagate precision across all frames, not just the last one
When equivalent completed state is found and it has additional precision
restrictions, BPF verifier propagates precision to
currently-being-verified state chain (i.e., including parent states) so
that if some of the states in the chain are not yet completed, necessary
precision restrictions are enforced.
Unfortunately, right now this happens only for the last frame (deepest
active subprogram's frame), not all the frames. This can lead to
incorrect matching of states due to missing precision marker. Currently
this doesn't seem possible as BPF verifier forces everything to precise
when validated BPF program has any subprograms. But with the next patch
lifting this restriction, this becomes problematic.
In fact, without this fix, we'll start getting failure in one of the
existing test_verifier test cases:
#906/p precise: cross frame pruning FAIL
Unexpected success to load!
verification time 48 usec
stack depth 0+0
processed 26 insns (limit 1000000) max_states_per_insn 3 total_states 17 peak_states 17 mark_read 8
This patch adds precision propagation across all frames.
Fixes:
|
||
|
Andrii Nakryiko
|
a3b666bfa9 |
bpf: propagate precision in ALU/ALU64 operations
When processing ALU/ALU64 operations (apart from BPF_MOV, which is
handled correctly already; and BPF_NEG and BPF_END are special and don't
have source register), if destination register is already marked
precise, this causes problem with potentially missing precision tracking
for the source register. E.g., when we have r1 >>= r5 and r1 is marked
precise, but r5 isn't, this will lead to r5 staying as imprecise. This
is due to the precision backtracking logic stopping early when it sees
r1 is already marked precise. If r1 wasn't precise, we'd keep
backtracking and would add r5 to the set of registers that need to be
marked precise. So there is a discrepancy here which can lead to invalid
and incompatible states matched due to lack of precision marking on r5.
If r1 wasn't precise, precision backtracking would correctly mark both
r1 and r5 as precise.
This is simple to fix, though. During the forward instruction simulation
pass, for arithmetic operations of `scalar <op>= scalar` form (where
<op> is ALU or ALU64 operations), if destination register is already
precise, mark source register as precise. This applies only when both
involved registers are SCALARs. `ptr += scalar` and `scalar += ptr`
cases are already handled correctly.
This does have (negative) effect on some selftest programs and few
Cilium programs. ~/baseline-tmp-results.csv are veristat results with
this patch, while ~/baseline-results.csv is without it. See post
scriptum for instructions on how to make Cilium programs testable with
veristat. Correctness has a price.
$ ./veristat -C -e file,prog,insns,states ~/baseline-results.csv ~/baseline-tmp-results.csv | grep -v '+0'
File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF)
----------------------- -------------------- --------------- --------------- ------------------ ---------------- ---------------- -------------------
bpf_cubic.bpf.linked1.o bpf_cubic_cong_avoid 997 1700 +703 (+70.51%) 62 90 +28 (+45.16%)
test_l4lb.bpf.linked1.o balancer_ingress 4559 5469 +910 (+19.96%) 118 126 +8 (+6.78%)
----------------------- -------------------- --------------- --------------- ------------------ ---------------- ---------------- -------------------
$ ./veristat -C -e file,prog,verdict,insns,states ~/baseline-results-cilium.csv ~/baseline-tmp-results-cilium.csv | grep -v '+0'
File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF)
------------- ------------------------------ --------------- --------------- ------------------ ---------------- ---------------- -------------------
bpf_host.o tail_nodeport_nat_ingress_ipv6 4448 5261 +813 (+18.28%) 234 247 +13 (+5.56%)
bpf_host.o tail_nodeport_nat_ipv6_egress 3396 3446 +50 (+1.47%) 201 203 +2 (+1.00%)
bpf_lxc.o tail_nodeport_nat_ingress_ipv6 4448 5261 +813 (+18.28%) 234 247 +13 (+5.56%)
bpf_overlay.o tail_nodeport_nat_ingress_ipv6 4448 5261 +813 (+18.28%) 234 247 +13 (+5.56%)
bpf_xdp.o tail_lb_ipv4 71736 73442 +1706 (+2.38%) 4295 4370 +75 (+1.75%)
------------- ------------------------------ --------------- --------------- ------------------ ---------------- ---------------- -------------------
P.S. To make Cilium ([0]) programs libbpf-compatible and thus
veristat-loadable, apply changes from topmost commit in [1], which does
minimal changes to Cilium source code, mostly around SEC() annotations
and BPF map definitions.
[0] https://github.com/cilium/cilium/
[1] https://github.com/anakryiko/cilium/commits/libbpf-friendliness
Fixes:
|
||
|
Kumar Kartikeya Dwivedi
|
f71b2f6417 |
bpf: Refactor map->off_arr handling
Refactor map->off_arr handling into generic functions that can work on their own without hardcoding map specific code. The btf_fields_offs structure is now returned from btf_parse_field_offs, which can be reused later for types in program BTF. All functions like copy_map_value, zero_map_value call generic underlying functions so that they can also be reused later for copying to values allocated in programs which encode specific fields. Later, some helper functions will also require access to this btf_field_offs structure to be able to skip over special fields at runtime. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221103191013.1236066-9-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Kumar Kartikeya Dwivedi
|
db55911782 |
bpf: Consolidate spin_lock, timer management into btf_record
Now that kptr_off_tab has been refactored into btf_record, and can hold more than one specific field type, accomodate bpf_spin_lock and bpf_timer as well. While they don't require any more metadata than offset, having all special fields in one place allows us to share the same code for allocated user defined types and handle both map values and these allocated objects in a similar fashion. As an optimization, we still keep spin_lock_off and timer_off offsets in the btf_record structure, just to avoid having to find the btf_field struct each time their offset is needed. This is mostly needed to manipulate such objects in a map value at runtime. It's ok to hardcode just one offset as more than one field is disallowed. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221103191013.1236066-8-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Kumar Kartikeya Dwivedi
|
aa3496accc |
bpf: Refactor kptr_off_tab into btf_record
To prepare the BPF verifier to handle special fields in both map values and program allocated types coming from program BTF, we need to refactor the kptr_off_tab handling code into something more generic and reusable across both cases to avoid code duplication. Later patches also require passing this data to helpers at runtime, so that they can work on user defined types, initialize them, destruct them, etc. The main observation is that both map values and such allocated types point to a type in program BTF, hence they can be handled similarly. We can prepare a field metadata table for both cases and store them in struct bpf_map or struct btf depending on the use case. Hence, refactor the code into generic btf_record and btf_field member structs. The btf_record represents the fields of a specific btf_type in user BTF. The cnt indicates the number of special fields we successfully recognized, and field_mask is a bitmask of fields that were found, to enable quick determination of availability of a certain field. Subsequently, refactor the rest of the code to work with these generic types, remove assumptions about kptr and kptr_off_tab, rename variables to more meaningful names, etc. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221103191013.1236066-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Jakub Kicinski
|
f2c24be55b |
bpf-for-netdev
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCY2RS7QAKCRDbK58LschI g6RVAQC1FdSXMrhn369NGCG1Vox1QYn2/5P32LSIV1BKqiQsywEAsxgYNrdCPTua ie91Q5IJGT9pFl1UR50UrgL11DI5BgI= =sdhO -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf Daniel Borkmann says: ==================== bpf 2022-11-04 We've added 8 non-merge commits during the last 3 day(s) which contain a total of 10 files changed, 113 insertions(+), 16 deletions(-). The main changes are: 1) Fix memory leak upon allocation failure in BPF verifier's stack state tracking, from Kees Cook. 2) Fix address leakage when BPF progs release reference to an object, from Youlin Li. 3) Fix BPF CI breakage from buggy in.h uapi header dependency, from Andrii Nakryiko. 4) Fix bpftool pin sub-command's argument parsing, from Pu Lehui. 5) Fix BPF sockmap lockdep warning by cancelling psock work outside of socket lock, from Cong Wang. 6) Follow-up for BPF sockmap to fix sk_forward_alloc accounting, from Wang Yufen. bpf-for-netdev * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: selftests/bpf: Add verifier test for release_reference() bpf: Fix wrong reg type conversion in release_reference() bpf, sock_map: Move cancel_work_sync() out of sock lock tools/headers: Pull in stddef.h to uapi to fix BPF selftests build in CI net/ipv4: Fix linux/in.h header dependencies bpftool: Fix NULL pointer dereference when pin {PROG, MAP, LINK} without FILE bpf, sockmap: Fix the sk->sk_forward_alloc warning of sk_stream_kill_queues bpf, verifier: Fix memory leak in array reallocation for stack state ==================== Link: https://lore.kernel.org/r/20221104000445.30761-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
||
|
Kumar Kartikeya Dwivedi
|
a28ace782e |
bpf: Drop reg_type_may_be_refcounted_or_null
It is not scalable to maintain a list of types that can have non-zero ref_obj_id. It is never set for scalars anyway, so just remove the conditional on register types and print it whenever it is non-zero. Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20221103191013.1236066-6-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Kumar Kartikeya Dwivedi
|
f5e477a861 |
bpf: Fix slot type check in check_stack_write_var_off
For the case where allow_ptr_leaks is false, code is checking whether
slot type is STACK_INVALID and STACK_SPILL and rejecting other cases.
This is a consequence of incorrectly checking for register type instead
of the slot type (NOT_INIT and SCALAR_VALUE respectively). Fix the
check.
Fixes:
|
||
|
Kumar Kartikeya Dwivedi
|
261f4664ca |
bpf: Clobber stack slot when writing over spilled PTR_TO_BTF_ID
When support was added for spilled PTR_TO_BTF_ID to be accessed by helper memory access, the stack slot was not overwritten to STACK_MISC (and that too is only safe when env->allow_ptr_leaks is true). This means that helpers who take ARG_PTR_TO_MEM and write to it may essentially overwrite the value while the verifier continues to track the slot for spilled register. This can cause issues when PTR_TO_BTF_ID is spilled to stack, and then overwritten by helper write access, which can then be passed to BPF helpers or kfuncs. Handle this by falling back to the case introduced in a later commit, which will also handle PTR_TO_BTF_ID along with other pointer types, i.e. |
||
|
Kumar Kartikeya Dwivedi
|
23da464dd6 |
bpf: Allow specifying volatile type modifier for kptrs
This is useful in particular to mark the pointer as volatile, so that compiler treats each load and store to the field as a volatile access. The alternative is having to define and use READ_ONCE and WRITE_ONCE in the BPF program. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20221103191013.1236066-3-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
Shang XiaoJing
|
66f0919c95 |
tracing: kprobe: Fix memory leak in test_gen_kprobe/kretprobe_cmd()
test_gen_kprobe_cmd() only free buf in fail path, hence buf will leak
when there is no failure. Move kfree(buf) from fail path to common path
to prevent the memleak. The same reason and solution in
test_gen_kretprobe_cmd().
unreferenced object 0xffff888143b14000 (size 2048):
comm "insmod", pid 52490, jiffies 4301890980 (age 40.553s)
hex dump (first 32 bytes):
70 3a 6b 70 72 6f 62 65 73 2f 67 65 6e 5f 6b 70 p:kprobes/gen_kp
72 6f 62 65 5f 74 65 73 74 20 64 6f 5f 73 79 73 robe_test do_sys
backtrace:
[<000000006d7b836b>] kmalloc_trace+0x27/0xa0
[<0000000009528b5b>] 0xffffffffa059006f
[<000000008408b580>] do_one_initcall+0x87/0x2a0
[<00000000c4980a7e>] do_init_module+0xdf/0x320
[<00000000d775aad0>] load_module+0x3006/0x3390
[<00000000e9a74b80>] __do_sys_finit_module+0x113/0x1b0
[<000000003726480d>] do_syscall_64+0x35/0x80
[<000000003441e93b>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
Link: https://lore.kernel.org/all/20221102072954.26555-1-shangxiaojing@huawei.com/
Fixes:
|
||
Masami Hiramatsu (Google)
|
61b304b73a |
tracing/fprobe: Fix to check whether fprobe is registered correctly
Since commit |
||
Rafael Mendonca
|
d05ea35e7e |
fprobe: Check rethook_alloc() return in rethook initialization
Check if fp->rethook succeeded to be allocated. Otherwise, if
rethook_alloc() fails, then we end up dereferencing a NULL pointer in
rethook_add_node().
Link: https://lore.kernel.org/all/20221025031209.954836-1-rafaelmendsr@gmail.com/
Fixes:
|
||
Li Qiang
|
4a6f316d68 |
kprobe: reverse kp->flags when arm_kprobe failed
In aggregate kprobe case, when arm_kprobe failed,
we need set the kp->flags with KPROBE_FLAG_DISABLED again.
If not, the 'kp' kprobe will been considered as enabled
but it actually not enabled.
Link: https://lore.kernel.org/all/20220902155820.34755-1-liq3ea@163.com/
Fixes:
|
||
Youlin Li
|
f1db20814a |
bpf: Fix wrong reg type conversion in release_reference()
Some helper functions will allocate memory. To avoid memory leaks, the
verifier requires the eBPF program to release these memories by calling
the corresponding helper functions.
When a resource is released, all pointer registers corresponding to the
resource should be invalidated. The verifier use release_references() to
do this job, by apply __mark_reg_unknown() to each relevant register.
It will give these registers the type of SCALAR_VALUE. A register that
will contain a pointer value at runtime, but of type SCALAR_VALUE, which
may allow the unprivileged user to get a kernel pointer by storing this
register into a map.
Using __mark_reg_not_init() while NOT allow_ptr_leaks can mitigate this
problem.
Fixes:
|
||
|
Jakub Kicinski
|
fbeb229a66 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
||
Li Huafei
|
0e792b89e6 |
ftrace: Fix use-after-free for dynamic ftrace_ops
KASAN reported a use-after-free with ftrace ops [1]. It was found from
vmcore that perf had registered two ops with the same content
successively, both dynamic. After unregistering the second ops, a
use-after-free occurred.
In ftrace_shutdown(), when the second ops is unregistered, the
FTRACE_UPDATE_CALLS command is not set because there is another enabled
ops with the same content. Also, both ops are dynamic and the ftrace
callback function is ftrace_ops_list_func, so the
FTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value
of 'command' will be 0 and ftrace_shutdown() will skip the rcu
synchronization.
However, ftrace may be activated. When the ops is released, another CPU
may be accessing the ops. Add the missing synchronization to fix this
problem.
[1]
BUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline]
BUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049
Read of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468
CPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132
show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b4/0x248 lib/dump_stack.c:118
print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387
__kasan_report mm/kasan/report.c:547 [inline]
kasan_report+0x118/0x210 mm/kasan/report.c:564
check_memory_region_inline mm/kasan/generic.c:187 [inline]
__asan_load8+0x98/0xc0 mm/kasan/generic.c:253
__ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline]
ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049
ftrace_graph_call+0x0/0x4
__might_sleep+0x8/0x100 include/linux/perf_event.h:1170
__might_fault mm/memory.c:5183 [inline]
__might_fault+0x58/0x70 mm/memory.c:5171
do_strncpy_from_user lib/strncpy_from_user.c:41 [inline]
strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139
getname_flags+0xb0/0x31c fs/namei.c:149
getname+0x2c/0x40 fs/namei.c:209
[...]
Allocated by task 14445:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:48
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc mm/kasan/common.c:479 [inline]
__kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449
kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493
kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950
kmalloc include/linux/slab.h:563 [inline]
kzalloc include/linux/slab.h:675 [inline]
perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230
perf_event_alloc kernel/events/core.c:11733 [inline]
__do_sys_perf_event_open kernel/events/core.c:11831 [inline]
__se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723
__arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723
[...]
Freed by task 14445:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:48
kasan_set_track+0x24/0x34 mm/kasan/common.c:56
kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358
__kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437
__kasan_slab_free mm/kasan/common.c:445 [inline]
kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446
slab_free_hook mm/slub.c:1569 [inline]
slab_free_freelist_hook mm/slub.c:1608 [inline]
slab_free mm/slub.c:3179 [inline]
kfree+0x12c/0xc10 mm/slub.c:4176
perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434
perf_event_alloc kernel/events/core.c:11733 [inline]
__do_sys_perf_event_open kernel/events/core.c:11831 [inline]
__se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723
[...]
Link: https://lore.kernel.org/linux-trace-kernel/20221103031010.166498-1-lihuafei1@huawei.com
Fixes:
|
||
Steven Rostedt (Google)
|
7433632c9f |
ring-buffer: Check for NULL cpu_buffer in ring_buffer_wake_waiters()
On some machines the number of listed CPUs may be bigger than the actual
CPUs that exist. The tracing subsystem allocates a per_cpu directory with
access to the per CPU ring buffer via a cpuX file. But to save space, the
ring buffer will only allocate buffers for online CPUs, even though the
CPU array will be as big as the nr_cpu_ids.
With the addition of waking waiters on the ring buffer when closing the
file, the ring_buffer_wake_waiters() now needs to make sure that the
buffer is allocated (with the irq_work allocated with it) before trying to
wake waiters, as it will cause a NULL pointer dereference.
While debugging this, I added a NULL check for the buffer itself (which is
OK to do), and also NULL pointer checks against buffer->buffers (which is
not fine, and will WARN) as well as making sure the CPU number passed in
is within the nr_cpu_ids (which is also not fine if it isn't).
Link: https://lore.kernel.org/all/87h6zklb6n.wl-tiwai@suse.de/
Link: https://lore.kernel.org/all/CAM6Wdxc0KRJMXVAA0Y=u6Jh2V=uWB-_Fn6M4xRuNppfXzL1mUg@mail.gmail.com/
Link: https://lkml.kernel.org/linux-trace-kernel/20221101191009.1e7378c8@rorschach.local.home
Cc: stable@vger.kernel.org
Cc: Steven Noonan <steven.noonan@gmail.com>
Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=1204705
Reported-by: Takashi Iwai <tiwai@suse.de>
Reported-by: Roland Ruckerbauer <roland.rucky@gmail.com>
Fixes:
|
||
|
Jakub Kicinski
|
b54a0d4094 |
bpf-next-for-netdev
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCY2GuKgAKCRDbK58LschI gy32AP9PI0e/bUGDExKJ8g97PeeEtnpj4TTI6g+XKILtYnyXlgD/Rk4j2D/f3IBF Ha9TmqYvAUim+U/g50vUrNuoNLNJ5w8= =OKC1 -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== bpf-next 2022-11-02 We've added 70 non-merge commits during the last 14 day(s) which contain a total of 96 files changed, 3203 insertions(+), 640 deletions(-). The main changes are: 1) Make cgroup local storage available to non-cgroup attached BPF programs such as tc BPF ones, from Yonghong Song. 2) Avoid unnecessary deadlock detection and failures wrt BPF task storage helpers, from Martin KaFai Lau. 3) Add LLVM disassembler as default library for dumping JITed code in bpftool, from Quentin Monnet. 4) Various kprobe_multi_link fixes related to kernel modules, from Jiri Olsa. 5) Optimize x86-64 JIT with emitting BMI2-based shift instructions, from Jie Meng. 6) Improve BPF verifier's memory type compatibility for map key/value arguments, from Dave Marchevsky. 7) Only create mmap-able data section maps in libbpf when data is exposed via skeletons, from Andrii Nakryiko. 8) Add an autoattach option for bpftool to load all object assets, from Wang Yufen. 9) Various memory handling fixes for libbpf and BPF selftests, from Xu Kuohai. 10) Initial support for BPF selftest's vmtest.sh on arm64, from Manu Bretelle. 11) Improve libbpf's BTF handling to dedup identical structs, from Alan Maguire. 12) Add BPF CI and denylist documentation for BPF selftests, from Daniel Müller. 13) Check BPF cpumap max_entries before doing allocation work, from Florian Lehner. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (70 commits) samples/bpf: Fix typo in README bpf: Remove the obsolte u64_stats_fetch_*_irq() users. bpf: check max_entries before allocating memory bpf: Fix a typo in comment for DFS algorithm bpftool: Fix spelling mistake "disasembler" -> "disassembler" selftests/bpf: Fix bpftool synctypes checking failure selftests/bpf: Panic on hard/soft lockup docs/bpf: Add documentation for new cgroup local storage selftests/bpf: Add test cgrp_local_storage to DENYLIST.s390x selftests/bpf: Add selftests for new cgroup local storage selftests/bpf: Fix test test_libbpf_str/bpf_map_type_str bpftool: Support new cgroup local storage libbpf: Support new cgroup local storage bpf: Implement cgroup storage available to non-cgroup-attached bpf progs bpf: Refactor some inode/task/sk storage functions for reuse bpf: Make struct cgroup btf id global selftests/bpf: Tracing prog can still do lookup under busy lock selftests/bpf: Ensure no task storage failure for bpf_lsm.s prog due to deadlock detection bpf: Add new bpf_task_storage_delete proto with no deadlock detection bpf: bpf_task_storage_delete_recur does lookup first before the deadlock check ... ==================== Link: https://lore.kernel.org/r/20221102062120.5724-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> |