3481 Commits

Author SHA1 Message Date
Benjamin Tissoires
56b4a177ae bpf: replace bpf_timer_init with a generic helper
No code change except for the new flags argument being stored in the
local data struct.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-2-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:24 -07:00
Benjamin Tissoires
be2749beff bpf: make timer data struct more generic
To be able to add workqueues and reuse most of the timer code, we need
to make bpf_hrtimer more generic.

There is no code change except that the new struct gets a new u64 flags
attribute. We are still below 2 cache lines, so this shouldn't impact
the current running codes.

The ordering is also changed. Everything related to async callback
is now on top of bpf_hrtimer.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-1-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-23 18:31:24 -07:00
Rafael Passos
a7de265cb2 bpf: Fix typos in comments
Found the following typos in comments, and fixed them:

s/unpriviledged/unprivileged/
s/reponsible/responsible/
s/possiblities/possibilities/
s/Divison/Division/
s/precsion/precision/
s/havea/have a/
s/reponsible/responsible/
s/responsibile/responsible/
s/tigher/tighter/
s/respecitve/respective/

Signed-off-by: Rafael Passos <rafael@rcpassos.me>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/6af7deb4-bb24-49e8-b3f1-8dd410597337@smtp-relay.sendinblue.com
2024-04-22 17:48:08 +02:00
Rafael Passos
e1a7545981 bpf: Fix typo in function save_aux_ptr_type
I found this typo in the save_aux_ptr_type function.
s/allow_trust_missmatch/allow_trust_mismatch/
I did not find this anywhere else in the codebase.

Signed-off-by: Rafael Passos <rafael@rcpassos.me>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/fbe1d636-8172-4698-9a5a-5a3444b55322@smtp-relay.sendinblue.com
2024-04-22 17:12:05 +02:00
Harishankar Vishwanathan
1f586614f3 bpf: Harden and/or/xor value tracking in verifier
This patch addresses a latent unsoundness issue in the
scalar(32)_min_max_and/or/xor functions. While it is not a bugfix,
it ensures that the functions produce sound outputs for all inputs.

The issue occurs in these functions when setting signed bounds. The
following example illustrates the issue for scalar_min_max_and(),
but it applies to the other functions.

In scalar_min_max_and() the following clause is executed when ANDing
positive numbers:

  /* ANDing two positives gives a positive, so safe to
   * cast result into s64.
   */
  dst_reg->smin_value = dst_reg->umin_value;
  dst_reg->smax_value = dst_reg->umax_value;

However, if umin_value and umax_value of dst_reg cross the sign boundary
(i.e., if (s64)dst_reg->umin_value > (s64)dst_reg->umax_value), then we
will end up with smin_value > smax_value, which is unsound.

Previous works [1, 2] have discovered and reported this issue. Our tool
Agni [2, 3] consideres it a false positive. This is because, during the
verification of the abstract operator scalar_min_max_and(), Agni restricts
its inputs to those passing through reg_bounds_sync(). This mimics
real-world verifier behavior, as reg_bounds_sync() is invariably executed
at the tail of every abstract operator. Therefore, such behavior is
unlikely in an actual verifier execution.

However, it is still unsound for an abstract operator to set signed bounds
such that smin_value > smax_value. This patch fixes it, making the abstract
operator sound for all (well-formed) inputs.

It is worth noting that while the previous code updated the signed bounds
(using the output unsigned bounds) only when the *input signed* bounds
were positive, the new code updates them whenever the *output unsigned*
bounds do not cross the sign boundary.

An alternative approach to fix this latent unsoundness would be to
unconditionally set the signed bounds to unbounded [S64_MIN, S64_MAX], and
let reg_bounds_sync() refine the signed bounds using the unsigned bounds
and the tnum. We found that our approach produces more precise (tighter)
bounds.

For example, consider these inputs to BPF_AND:

  /* dst_reg */
  var_off.value: 8608032320201083347
  var_off.mask: 615339716653692460
  smin_value: 8070450532247928832
  smax_value: 8070450532247928832
  umin_value: 13206380674380886586
  umax_value: 13206380674380886586
  s32_min_value: -2110561598
  s32_max_value: -133438816
  u32_min_value: 4135055354
  u32_max_value: 4135055354

  /* src_reg */
  var_off.value: 8584102546103074815
  var_off.mask: 9862641527606476800
  smin_value: 2920655011908158522
  smax_value: 7495731535348625717
  umin_value: 7001104867969363969
  umax_value: 8584102543730304042
  s32_min_value: -2097116671
  s32_max_value: 71704632
  u32_min_value: 1047457619
  u32_max_value: 4268683090

After going through tnum_and() -> scalar32_min_max_and() ->
scalar_min_max_and() -> reg_bounds_sync(), our patch produces the following
bounds for s32:

  s32_min_value: -1263875629
  s32_max_value: -159911942

Whereas, setting the signed bounds to unbounded in scalar_min_max_and()
produces:

  s32_min_value: -1263875629
  s32_max_value: -1

As observed, our patch produces a tighter s32 bound. We also confirmed
using Agni and SMT verification that our patch always produces signed
bounds that are equal to or more precise than setting the signed bounds to
unbounded in scalar_min_max_and().

  [1] https://sanjit-bhat.github.io/assets/pdf/ebpf-verifier-range-analysis22.pdf
  [2] https://link.springer.com/chapter/10.1007/978-3-031-37709-9_12
  [3] https://github.com/bpfverif/agni

Co-developed-by: Matan Shachnai <m.shachnai@rutgers.edu>
Signed-off-by: Matan Shachnai <m.shachnai@rutgers.edu>
Co-developed-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Signed-off-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Co-developed-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240402212039.51815-1-harishankar.vishwanathan@gmail.com
Link: https://lore.kernel.org/bpf/20240416115303.331688-1-harishankar.vishwanathan@gmail.com
2024-04-16 17:55:27 +02:00
Ard Biesheuvel
fc5eb4a84e btf: Avoid weak external references
If the BTF code is enabled in the build configuration, the start/stop
BTF markers are guaranteed to exist. Only when CONFIG_DEBUG_INFO_BTF=n,
the references in btf_parse_vmlinux() will remain unsatisfied, relying
on the weak linkage of the external references to avoid breaking the
build.

Avoid GOT based relocations to these markers in the final executable by
dropping the weak attribute and instead, make btf_parse_vmlinux() return
ERR_PTR(-ENOENT) directly if CONFIG_DEBUG_INFO_BTF is not enabled to
begin with.  The compiler will drop any subsequent references to
__start_BTF and __stop_BTF in that case, allowing the link to succeed.

Note that Clang will notice that taking the address of __start_BTF can
no longer yield NULL, so testing for that condition becomes unnecessary.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240415162041.2491523-8-ardb+git@google.com
2024-04-16 16:35:13 +02:00
Anton Protopopov
37eacb9f6e bpf: Fix a verifier verbose message
Long ago a map file descriptor in a pseudo ldimm64 instruction could
only be present as an immediate value insn[0].imm, and thus this value
was used in a verbose verifier message printed when the file descriptor
wasn't valid. Since addition of BPF_PSEUDO_MAP_IDX_VALUE/BPF_PSEUDO_MAP_IDX
the insn[0].imm field can also contain an index pointing to the file
descriptor in the attr.fd_array array. However, if the file descriptor
is invalid, the verifier still prints the verbose message containing
value of insn[0].imm. Patch the verifier message to always print the
actual file descriptor value.

Fixes: 387544bfa291 ("bpf: Introduce fd_idx")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240412141100.3562942-1-aspsk@isovalent.com
2024-04-12 18:37:20 +02:00
Paul E. McKenney
1e52af7f02 bpf: Choose RCU Tasks based on TASKS_RCU rather than PREEMPTION
The advent of CONFIG_PREEMPT_AUTO, AKA lazy preemption, will mean that
even kernels built with CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY
might see the occasional preemption, and that this preemption just might
happen within a trampoline.

Therefore, update bpf_tramp_image_put() to choose call_rcu_tasks()
based on CONFIG_TASKS_RCU instead of CONFIG_PREEMPTION.

This change might enable further simplifications, but the goal of this
effort is to make the code safe, not necessarily optimal.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Song Liu <song@kernel.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <bpf@vger.kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-12 11:23:25 +02:00
Yonghong Song
699c23f02c bpf: Add bpf_link support for sk_msg and sk_skb progs
Add bpf_link support for sk_msg and sk_skb programs. We have an
internal request to support bpf_link for sk_msg programs so user
space can have a uniform handling with bpf_link based libbpf
APIs. Using bpf_link based libbpf API also has a benefit which
makes system robust by decoupling prog life cycle and
attachment life cycle.

Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240410043527.3737160-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-10 19:52:25 -07:00
Alexei Starovoitov
d503a04f8b bpf: Add support for certain atomics in bpf_arena to x86 JIT
Support atomics in bpf_arena that can be JITed as a single x86 instruction.
Instructions that are JITed as loops are not supported at the moment,
since they require more complex extable and loop logic.

JITs can choose to do smarter things with bpf_jit_supports_insn().
Like arm64 may decide to support all bpf atomics instructions
when emit_lse_atomic is available and none in ll_sc mode.

bpf_jit_supports_percpu_insn(), bpf_jit_supports_ptr_xchg() and
other such callbacks can be replaced with bpf_jit_supports_insn()
in the future.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240405231134.17274-1-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-09 10:24:26 -07:00
Paul E. McKenney
b993115b44 bpf: Select new NEED_TASKS_RCU Kconfig option
Currently, if a Kconfig option depends on TASKS_RCU, it conditionally does
"select TASKS_RCU if PREEMPTION".  This works, but requires any change in
this enablement logic to be replicated across all such "select" clauses.
A new NEED_TASKS_RCU Kconfig option has been created to allow this
enablement logic to be in one place in kernel/rcu/Kconfig.

Therefore, make BPF select the new NEED_TASKS_RCU Kconfig option.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Song Liu <song@kernel.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: <bpf@vger.kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09 15:13:05 +02:00
David Vernet
a8e03b6bbb bpf: Allow invoking kfuncs from BPF_PROG_TYPE_SYSCALL progs
Currently, a set of core BPF kfuncs (e.g. bpf_task_*, bpf_cgroup_*,
bpf_cpumask_*, etc) cannot be invoked from BPF_PROG_TYPE_SYSCALL
programs. The whitelist approach taken for enabling kfuncs makes sense:
it not safe to call these kfuncs from every program type. For example,
it may not be safe to call bpf_task_acquire() in an fentry to
free_task().

BPF_PROG_TYPE_SYSCALL, on the other hand, is a perfectly safe program
type from which to invoke these kfuncs, as it's a very controlled
environment, and we should never be able to run into any of the typical
problems such as recursive invoations, acquiring references on freeing
kptrs, etc. Being able to invoke these kfuncs would be useful, as
BPF_PROG_TYPE_SYSCALL can be invoked with BPF_PROG_RUN, and would
therefore enable user space programs to synchronously call into BPF to
manipulate these kptrs.

This patch therefore enables invoking the aforementioned core kfuncs
from BPF_PROG_TYPE_SYSCALL progs.

Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20240405143041.632519-2-void@manifault.com
2024-04-05 10:56:09 -07:00
Philo Lu
9d482da9e1 bpf: allow invoking bpf_for_each_map_elem with different maps
Taking different maps within a single bpf_for_each_map_elem call is not
allowed before, because from the second map,
bpf_insn_aux_data->map_ptr_state will be marked as *poison*. In fact
both map_ptr and state are needed to support this use case: map_ptr is
used by set_map_elem_callback_state() while poison state is needed to
determine whether to use direct call.

Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240405025536.18113-3-lulie@linux.alibaba.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-05 10:31:17 -07:00
Philo Lu
0a525621b7 bpf: store both map ptr and state in bpf_insn_aux_data
Currently, bpf_insn_aux_data->map_ptr_state is used to store either
map_ptr or its poison state (i.e., BPF_MAP_PTR_POISON). Thus
BPF_MAP_PTR_POISON must be checked before reading map_ptr. In certain
cases, we may need valid map_ptr even in case of poison state.
This will be explained in next patch with bpf_for_each_map_elem()
helper.

This patch changes map_ptr_state into a new struct including both map
pointer and its state (poison/unpriv). It's in the same union with
struct bpf_loop_inline_state, so there is no extra memory overhead.
Besides, macros BPF_MAP_PTR_UNPRIV/BPF_MAP_PTR_POISON/BPF_MAP_PTR are no
longer needed.

This patch does not change any existing functionality.

Signed-off-by: Philo Lu <lulie@linux.alibaba.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240405025536.18113-2-lulie@linux.alibaba.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-05 10:31:17 -07:00
Arnd Bergmann
58babe2718 bpf: fix perf_snapshot_branch_stack link failure
The newly added code to handle bpf_get_branch_snapshot fails to link when
CONFIG_PERF_EVENTS is disabled:

aarch64-linux-ld: kernel/bpf/verifier.o: in function `do_misc_fixups':
verifier.c:(.text+0x1090c): undefined reference to `__SCK__perf_snapshot_branch_stack'

Add a build-time check for that Kconfig symbol around the code to
remove the link time dependency.

Fixes: 314a53623cd4 ("bpf: inline bpf_get_branch_snapshot() helper")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240405142637.577046-1-arnd@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-05 08:39:15 -07:00
Andrii Nakryiko
1f2a74b41e bpf: prevent r10 register from being marked as precise
r10 is a special register that is not under BPF program's control and is
always effectively precise. The rest of precision logic assumes that
only r0-r9 SCALAR registers are marked as precise, so prevent r10 from
being marked precise.

This can happen due to signed cast instruction allowing to do something
like `r0 = (s8)r10;`, which later, if r0 needs to be precise, would lead
to an attempt to mark r10 as precise.

Prevent this with an extra check during instruction backtracking.

Fixes: 8100928c8814 ("bpf: Support new sign-extension mov insns")
Reported-by: syzbot+148110ee7cf72f39f33e@syzkaller.appspotmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240404214536.3551295-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-04 18:31:08 -07:00
Jakub Kicinski
cf1ca1f66d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/ip_gre.c
  17af420545a7 ("erspan: make sure erspan_base_hdr is present in skb->head")
  5832c4a77d69 ("ip_tunnel: convert __be16 tunnel flags to bitmaps")
https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/

Adjacent changes:

net/ipv6/ip6_fib.c
  d21d40605bca ("ipv6: Fix infinite recursion in fib6_dump_done().")
  5fc68320c1fb ("ipv6: remove RTNL protection from inet6_dump_fib()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-04 18:01:07 -07:00
Linus Torvalds
c88b9b4cde Including fixes from netfilter, bluetooth and bpf.
Fairly usual collection of driver and core fixes. The large selftest
 accompanying one of the fixes is also becoming a common occurrence.
 
 Current release - regressions:
 
  - ipv6: fix infinite recursion in fib6_dump_done()
 
  - net/rds: fix possible null-deref in newly added error path
 
 Current release - new code bugs:
 
  - net: do not consume a full cacheline for system_page_pool
 
  - bpf: fix bpf_arena-related file descriptor leaks in the verifier
 
  - drv: ice: fix freeing uninitialized pointers, fixing misuse of
    the newfangled __free() auto-cleanup
 
 Previous releases - regressions:
 
  - x86/bpf: fixes the BPF JIT with retbleed=stuff
 
  - xen-netfront: add missing skb_mark_for_recycle, fix page pool
    accounting leaks, revealed by recently added explicit warning
 
  - tcp: fix bind() regression for v6-only wildcard and v4-mapped-v6
    non-wildcard addresses
 
  - Bluetooth:
    - replace "hci_qca: Set BDA quirk bit if fwnode exists in DT"
      with better workarounds to un-break some buggy Qualcomm devices
    - set conn encrypted before conn establishes, fix re-connecting
      to some headsets which use slightly unusual sequence of msgs
 
  - mptcp:
    - prevent BPF accessing lowat from a subflow socket
    - don't account accept() of non-MPC client as fallback to TCP
 
  - drv: mana: fix Rx DMA datasize and skb_over_panic
 
  - drv: i40e: fix VF MAC filter removal
 
 Previous releases - always broken:
 
  - gro: various fixes related to UDP tunnels - netns crossing problems,
    incorrect checksum conversions, and incorrect packet transformations
    which may lead to panics
 
  - bpf: support deferring bpf_link dealloc to after RCU grace period
 
  - nf_tables:
    - release batch on table validation from abort path
    - release mutex after nft_gc_seq_end from abort path
    - flush pending destroy work before exit_net release
 
  - drv: r8169: skip DASH fw status checks when DASH is disabled
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter, bluetooth and bpf.

  Fairly usual collection of driver and core fixes. The large selftest
  accompanying one of the fixes is also becoming a common occurrence.

  Current release - regressions:

   - ipv6: fix infinite recursion in fib6_dump_done()

   - net/rds: fix possible null-deref in newly added error path

  Current release - new code bugs:

   - net: do not consume a full cacheline for system_page_pool

   - bpf: fix bpf_arena-related file descriptor leaks in the verifier

   - drv: ice: fix freeing uninitialized pointers, fixing misuse of the
     newfangled __free() auto-cleanup

  Previous releases - regressions:

   - x86/bpf: fixes the BPF JIT with retbleed=stuff

   - xen-netfront: add missing skb_mark_for_recycle, fix page pool
     accounting leaks, revealed by recently added explicit warning

   - tcp: fix bind() regression for v6-only wildcard and v4-mapped-v6
     non-wildcard addresses

   - Bluetooth:
      - replace "hci_qca: Set BDA quirk bit if fwnode exists in DT" with
        better workarounds to un-break some buggy Qualcomm devices
      - set conn encrypted before conn establishes, fix re-connecting to
        some headsets which use slightly unusual sequence of msgs

   - mptcp:
      - prevent BPF accessing lowat from a subflow socket
      - don't account accept() of non-MPC client as fallback to TCP

   - drv: mana: fix Rx DMA datasize and skb_over_panic

   - drv: i40e: fix VF MAC filter removal

  Previous releases - always broken:

   - gro: various fixes related to UDP tunnels - netns crossing
     problems, incorrect checksum conversions, and incorrect packet
     transformations which may lead to panics

   - bpf: support deferring bpf_link dealloc to after RCU grace period

   - nf_tables:
      - release batch on table validation from abort path
      - release mutex after nft_gc_seq_end from abort path
      - flush pending destroy work before exit_net release

   - drv: r8169: skip DASH fw status checks when DASH is disabled"

* tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits)
  netfilter: validate user input for expected length
  net/sched: act_skbmod: prevent kernel-infoleak
  net: usb: ax88179_178a: avoid the interface always configured as random address
  net: dsa: sja1105: Fix parameters order in sja1110_pcs_mdio_write_c45()
  net: ravb: Always update error counters
  net: ravb: Always process TX descriptor ring
  netfilter: nf_tables: discard table flag update with pending basechain deletion
  netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get()
  netfilter: nf_tables: reject new basechain after table flag update
  netfilter: nf_tables: flush pending destroy work before exit_net release
  netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path
  netfilter: nf_tables: release batch on table validation from abort path
  Revert "tg3: Remove residual error handling in tg3_suspend"
  tg3: Remove residual error handling in tg3_suspend
  net: mana: Fix Rx DMA datasize and skb_over_panic
  net/sched: fix lockdep splat in qdisc_tree_reduce_backlog()
  net: phy: micrel: lan8814: Fix when enabling/disabling 1-step timestamping
  net: stmmac: fix rx queue priority assignment
  net: txgbe: fix i2c dev name cannot match clkdev
  net: fec: Set mac_managed_pm during probe
  ...
2024-04-04 14:49:10 -07:00
Andrii Nakryiko
314a53623c bpf: inline bpf_get_branch_snapshot() helper
Inline bpf_get_branch_snapshot() helper using architecture-agnostic
inline BPF code which calls directly into underlying callback of
perf_snapshot_branch_stack static call. This callback is set early
during kernel initialization and is never updated or reset, so it's ok
to fetch actual implementation using static_call_query() and call
directly into it.

This change eliminates a full function call and saves one LBR entry
in PERF_SAMPLE_BRANCH_ANY LBR mode.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240404002640.1774210-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-04 13:08:01 -07:00
Alexei Starovoitov
af682b767a bpf: Optimize emit_mov_imm64().
Turned out that bpf prog callback addresses, bpf prog addresses
used in bpf_trampoline, and in other cases the 64-bit address
can be represented as sign extended 32-bit value.

According to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82339
"Skylake has 0.64c throughput for mov r64, imm64, vs. 0.25 for mov r32, imm32."
So use shorter encoding and faster instruction when possible.

Special care is needed in jit_subprogs(), since bpf_pseudo_func()
instruction cannot change its size during the last step of JIT.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/CAADnVQKFfpY-QZBrOU2CG8v2du8Lgyb7MNVmOZVK_yTyOdNbBA@mail.gmail.com
Link: https://lore.kernel.org/bpf/20240401233800.42737-1-alexei.starovoitov@gmail.com
2024-04-04 16:13:26 +02:00
Andrii Nakryiko
0b56e637f7 bpf: inline bpf_map_lookup_elem() helper for PERCPU_HASH map
Using new per-CPU BPF instruction, partially inline
bpf_map_lookup_elem() helper for per-CPU hashmap BPF map. Just like for
normal HASH map, we still generate a call into __htab_map_lookup_elem(),
but after that we resolve per-CPU element address using a new
instruction, saving on extra functions calls.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20240402021307.1012571-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03 10:29:56 -07:00
Andrii Nakryiko
db69718b8e bpf: inline bpf_map_lookup_elem() for PERCPU_ARRAY maps
Using new per-CPU BPF instruction implement inlining for per-CPU ARRAY
map lookup helper, if BPF JIT support is present.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20240402021307.1012571-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03 10:29:56 -07:00
Andrii Nakryiko
1ae6921009 bpf: inline bpf_get_smp_processor_id() helper
If BPF JIT supports per-CPU MOV instruction, inline bpf_get_smp_processor_id()
to eliminate unnecessary function calls.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20240402021307.1012571-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03 10:29:56 -07:00
Andrii Nakryiko
7bdbf74463 bpf: add special internal-only MOV instruction to resolve per-CPU addrs
Add a new BPF instruction for resolving absolute addresses of per-CPU
data from their per-CPU offsets. This instruction is internal-only and
users are not allowed to use them directly. They will only be used for
internal inlining optimizations for now between BPF verifier and BPF JITs.

We use a special BPF_MOV | BPF_ALU64 | BPF_X form with insn->off field
set to BPF_ADDR_PERCPU = -1. I used negative offset value to distinguish
them from positive ones used by user-exposed instructions.

Such instruction performs a resolution of a per-CPU offset stored in
a register to a valid kernel address which can be dereferenced. It is
useful in any use case where absolute address of a per-CPU data has to
be resolved (e.g., in inlining bpf_map_lookup_elem()).

BPF disassembler is also taught to recognize them to support dumping
final BPF assembly code (non-JIT'ed version).

Add arch-specific way for BPF JITs to mark support for this instructions.

This patch also adds support for these instructions in x86-64 BPF JIT.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20240402021307.1012571-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-03 10:29:55 -07:00
Justin Stitt
2e114248e0 bpf: Replace deprecated strncpy with strscpy
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

bpf sym names get looked up and compared/cleaned with various string
apis. This suggests they need to be NUL-terminated (strncpy() suggests
this but does not guarantee it).

|	static int compare_symbol_name(const char *name, char *namebuf)
|	{
|		cleanup_symbol_name(namebuf);
|		return strcmp(name, namebuf);
|	}

|	static void cleanup_symbol_name(char *s)
|	{
|		...
|		res = strstr(s, ".llvm.");
|		...
|	}

Use strscpy() as this method guarantees NUL-termination on the
destination buffer.

This patch also replaces two uses of strncpy() used in log.c. These are
simple replacements as postfix has been zero-initialized on the stack
and has source arguments with a size less than the destination's size.

Note that this patch uses the new 2-argument version of strscpy
introduced in commit e6584c3964f2f ("string: Allow 2-argument strscpy()").

Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Link: https://lore.kernel.org/bpf/20240402-strncpy-kernel-bpf-core-c-v1-1-7cb07a426e78@google.com
2024-04-03 16:57:41 +02:00
Jose Fernandez
ce09cbdd98 bpf: Improve program stats run-time calculation
This patch improves the run-time calculation for program stats by
capturing the duration as soon as possible after the program returns.

Previously, the duration included u64_stats_t operations. While the
instrumentation overhead is part of the total time spent when stats are
enabled, distinguishing between the program's native execution time and
the time spent due to instrumentation is crucial for accurate
performance analysis.

By making this change, the patch facilitates more precise optimization
of BPF programs, enabling users to understand their performance in
environments without stats enabled.

I used a virtualized environment to measure the run-time over one minute
for a basic raw_tracepoint/sys_enter program, which just increments a
local counter. Although the virtualization introduced some performance
degradation that could affect the results, I observed approximately a
16% decrease in average run-time reported by stats with this change
(310 -> 260 nsec).

Signed-off-by: Jose Fernandez <josef@netflix.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240402034010.25060-1-josef@netflix.com
2024-04-02 16:51:15 +02:00
Anton Protopopov
9dc182c58b bpf: Add a verbose message if map limit is reached
When more than 64 maps are used by a program and its subprograms the
verifier returns -E2BIG. Add a verbose message which highlights the
source of the error and also print the actual limit.

Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20240402073347.195920-1-aspsk@isovalent.com
2024-04-02 16:12:00 +02:00
Linus Torvalds
7e40c2100c Kbuild fixes for v6.9
- Deduplicate Kconfig entries for CONFIG_CXL_PMU
 
  - Fix unselectable choice entry in MIPS Kconfig, and forbid this
    structure
 
  - Remove unused include/asm-generic/export.h
 
  - Fix a NULL pointer dereference bug in modpost
 
  - Enable -Woverride-init warning consistently with W=1
 
  - Drop KCSAN flags from *.mod.c files
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Merge tag 'kbuild-fixes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Deduplicate Kconfig entries for CONFIG_CXL_PMU

 - Fix unselectable choice entry in MIPS Kconfig, and forbid this
   structure

 - Remove unused include/asm-generic/export.h

 - Fix a NULL pointer dereference bug in modpost

 - Enable -Woverride-init warning consistently with W=1

 - Drop KCSAN flags from *.mod.c files

* tag 'kbuild-fixes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: Fix typo HEIGTH to HEIGHT
  Documentation/llvm: Note s390 LLVM=1 support with LLVM 18.1.0 and newer
  kbuild: Disable KCSAN for autogenerated *.mod.c intermediaries
  kbuild: make -Woverride-init warnings more consistent
  modpost: do not make find_tosym() return NULL
  export.h: remove include/asm-generic/export.h
  kconfig: do not reparent the menu inside a choice block
  MIPS: move unselectable FIT_IMAGE_FDT_EPM5 out of the "System type" choice
  cxl: remove CONFIG_CXL_PMU entry in drivers/cxl/Kconfig
2024-03-31 11:23:51 -07:00
Arnd Bergmann
c40845e319 kbuild: make -Woverride-init warnings more consistent
The -Woverride-init warn about code that may be intentional or not,
but the inintentional ones tend to be real bugs, so there is a bit of
disagreement on whether this warning option should be enabled by default
and we have multiple settings in scripts/Makefile.extrawarn as well as
individual subsystems.

Older versions of clang only supported -Wno-initializer-overrides with
the same meaning as gcc's -Woverride-init, though all supported versions
now work with both. Because of this difference, an earlier cleanup of
mine accidentally turned the clang warning off for W=1 builds and only
left it on for W=2, while it's still enabled for gcc with W=1.

There is also one driver that only turns the warning off for newer
versions of gcc but not other compilers, and some but not all the
Makefiles still use a cc-disable-warning conditional that is no
longer needed with supported compilers here.

Address all of the above by removing the special cases for clang
and always turning the warning off unconditionally where it got
in the way, using the syntax that is supported by both compilers.

Fixes: 2cd3271b7a31 ("kbuild: avoid duplicate warning options")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-03-31 11:32:26 +09:00
Alexei Starovoitov
59f2f84117 bpf: Avoid kfree_rcu() under lock in bpf_lpm_trie.
syzbot reported the following lock sequence:
cpu 2:
  grabs timer_base lock
    spins on bpf_lpm lock

cpu 1:
  grab rcu krcp lock
    spins on timer_base lock

cpu 0:
  grab bpf_lpm lock
    spins on rcu krcp lock

bpf_lpm lock can be the same.
timer_base lock can also be the same due to timer migration.
but rcu krcp lock is always per-cpu, so it cannot be the same lock.
Hence it's a false positive.
To avoid lockdep complaining move kfree_rcu() after spin_unlock.

Reported-by: syzbot+1fa663a2100308ab6eab@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240329171439.37813-1-alexei.starovoitov@gmail.com
2024-03-29 11:10:41 -07:00
Anton Protopopov
6dae957c8e bpf: fix possible file descriptor leaks in verifier
The resolve_pseudo_ldimm64() function might have leaked file
descriptors when BPF_MAP_TYPE_ARENA was used in a program (some
error paths missed a corresponding fdput). Add missing fdputs.

v2:
  remove unrelated changes from the fix

Fixes: 6082b6c328b5 ("bpf: Recognize addr_space_cast instruction in the verifier.")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20240329071106.67968-1-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-29 09:19:55 -07:00
Martin KaFai Lau
e8742081db bpf: Mark bpf prog stack with kmsan_unposion_memory in interpreter mode
syzbot reported uninit memory usages during map_{lookup,delete}_elem.

==========
BUG: KMSAN: uninit-value in __dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]
BUG: KMSAN: uninit-value in dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796
__dev_map_lookup_elem kernel/bpf/devmap.c:441 [inline]
dev_map_lookup_elem+0xf3/0x170 kernel/bpf/devmap.c:796
____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [inline]
bpf_map_lookup_elem+0x5c/0x80 kernel/bpf/helpers.c:38
___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997
__bpf_prog_run256+0xb5/0xe0 kernel/bpf/core.c:2237
==========

The reproducer should be in the interpreter mode.

The C reproducer is trying to run the following bpf prog:

    0: (18) r0 = 0x0
    2: (18) r1 = map[id:49]
    4: (b7) r8 = 16777216
    5: (7b) *(u64 *)(r10 -8) = r8
    6: (bf) r2 = r10
    7: (07) r2 += -229
            ^^^^^^^^^^

    8: (b7) r3 = 8
    9: (b7) r4 = 0
   10: (85) call dev_map_lookup_elem#1543472
   11: (95) exit

It is due to the "void *key" (r2) passed to the helper. bpf allows uninit
stack memory access for bpf prog with the right privileges. This patch
uses kmsan_unpoison_memory() to mark the stack as initialized.

This should address different syzbot reports on the uninit "void *key"
argument during map_{lookup,delete}_elem.

Reported-by: syzbot+603bcd9b0bf1d94dbb9b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000f9ce6d061494e694@google.com/
Reported-by: syzbot+eb02dc7f03dce0ef39f3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000a5c69c06147c2238@google.com/
Reported-by: syzbot+b4e65ca24fd4d0c734c3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000ac56fb06143b6cfa@google.com/
Reported-by: syzbot+d2b113dc9fea5e1d2848@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/0000000000000d69b206142d1ff7@google.com/
Reported-by: syzbot+1a3cf6f08d68868f9db3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/0000000000006f876b061478e878@google.com/
Tested-by: syzbot+1a3cf6f08d68868f9db3@syzkaller.appspotmail.com
Suggested-by: Yonghong Song <yonghong.song@linux.dev>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240328185801.1843078-1-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 19:00:59 -07:00
Andrii Nakryiko
1a80dbcb2d bpf: support deferring bpf_link dealloc to after RCU grace period
BPF link for some program types is passed as a "context" which can be
used by those BPF programs to look up additional information. E.g., for
multi-kprobes and multi-uprobes, link is used to fetch BPF cookie values.

Because of this runtime dependency, when bpf_link refcnt drops to zero
there could still be active BPF programs running accessing link data.

This patch adds generic support to defer bpf_link dealloc callback to
after RCU GP, if requested. This is done by exposing two different
deallocation callbacks, one synchronous and one deferred. If deferred
one is provided, bpf_link_free() will schedule dealloc_deferred()
callback to happen after RCU GP.

BPF is using two flavors of RCU: "classic" non-sleepable one and RCU
tasks trace one. The latter is used when sleepable BPF programs are
used. bpf_link_free() accommodates that by checking underlying BPF
program's sleepable flag, and goes either through normal RCU GP only for
non-sleepable, or through RCU tasks trace GP *and* then normal RCU GP
(taking into account rcu_trace_implies_rcu_gp() optimization), if BPF
program is sleepable.

We use this for multi-kprobe and multi-uprobe links, which dereference
link during program run. We also preventively switch raw_tp link to use
deferred dealloc callback, as upcoming changes in bpf-next tree expose
raw_tp link data (specifically, cookie value) to BPF program at runtime
as well.

Fixes: 0dcac2725406 ("bpf: Add multi kprobe link")
Fixes: 89ae89f53d20 ("bpf: Add multi uprobe link")
Reported-by: syzbot+981935d9485a560bfbcb@syzkaller.appspotmail.com
Reported-by: syzbot+2cb5a6c573e98db598cc@syzkaller.appspotmail.com
Reported-by: syzbot+62d8b26793e8a2bd0516@syzkaller.appspotmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240328052426.3042617-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 18:47:45 -07:00
Yafang Shao
ee3bad033d bpf: Mitigate latency spikes associated with freeing non-preallocated htab
Following the recent upgrade of one of our BPF programs, we encountered
significant latency spikes affecting other applications running on the same
host. After thorough investigation, we identified that these spikes were
primarily caused by the prolonged duration required to free a
non-preallocated htab with approximately 2 million keys.

Notably, our kernel configuration lacks the presence of CONFIG_PREEMPT. In
scenarios where kernel execution extends excessively, other threads might
be starved of CPU time, resulting in latency issues across the system. To
mitigate this, we've adopted a proactive approach by incorporating
cond_resched() calls within the kernel code. This ensures that during
lengthy kernel operations, the scheduler is invoked periodically to provide
opportunities for other threads to execute.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240327032022.78391-1-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 18:31:40 -07:00
Andrii Nakryiko
3124591f68 bpf: add bpf_modify_return_test_tp() kfunc triggering tracepoint
Add a simple bpf_modify_return_test_tp() kfunc, available to all program
types, that is useful for various testing and benchmarking scenarios, as
it allows to trigger most tracing BPF program types from BPF side,
allowing to do complex testing and benchmarking scenarios.

It is also attachable to for fmod_ret programs, making it a good and
simple way to trigger fmod_ret program under test/benchmark.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240326162151.3981687-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 18:31:40 -07:00
Haiyue Wang
55fc888ded bpf,arena: Use helper sizeof_field in struct accessors
Use the well defined helper sizeof_field() to calculate the size of a
struct member, instead of doing custom calculations.

Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Link: https://lore.kernel.org/r/20240327065334.8140-1-haiyue.wang@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 18:31:36 -07:00
Mykyta Yatsenko
786bf0e7e2 bpf: improve error message for unsupported helper
BPF verifier emits "unknown func" message when given BPF program type
does not support BPF helper. This message may be confusing for users, as
important context that helper is unknown only to current program type is
not provided.

This patch changes message to "program of this type cannot use helper "
and aligns dependent code in libbpf and tests. Any suggestions on
improving/changing this message are welcome.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20240325152210.377548-1-yatsenko@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-28 18:30:53 -07:00
Jakub Kicinski
5e47fbe5ce Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts, or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-28 17:25:57 -07:00
Andrei Matei
ecc6a21018 bpf: Protect against int overflow for stack access size
This patch re-introduces protection against the size of access to stack
memory being negative; the access size can appear negative as a result
of overflowing its signed int representation. This should not actually
happen, as there are other protections along the way, but we should
protect against it anyway. One code path was missing such protections
(fixed in the previous patch in the series), causing out-of-bounds array
accesses in check_stack_range_initialized(). This patch causes the
verification of a program with such a non-sensical access size to fail.

This check used to exist in a more indirect way, but was inadvertendly
removed in a833a17aeac7.

Fixes: a833a17aeac7 ("bpf: Fix verification of indirect var-off stack access")
Reported-by: syzbot+33f4297b5f927648741a@syzkaller.appspotmail.com
Reported-by: syzbot+aafd0513053a1cbf52ef@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/CAADnVQLORV5PT0iTAhRER+iLBTkByCYNBYyvBSgjN1T31K+gOw@mail.gmail.com/
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Link: https://lore.kernel.org/r/20240327024245.318299-3-andreimatei1@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-27 09:56:36 -07:00
Andrei Matei
a8d89feba7 bpf: Check bloom filter map value size
This patch adds a missing check to bloom filter creating, rejecting
values above KMALLOC_MAX_SIZE. This brings the bloom map in line with
many other map types.

The lack of this protection can cause kernel crashes for value sizes
that overflow int's. Such a crash was caught by syzkaller. The next
patch adds more guard-rails at a lower level.

Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240327024245.318299-2-andreimatei1@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-27 09:56:17 -07:00
Hari Bathini
96b98a6552 bpf: fix warning for crash_kexec
With [1], crash dump specific code is moved out of CONFIG_KEXEC_CORE
and placed under CONFIG_CRASH_DUMP, where it is more appropriate.
And since CONFIG_KEXEC & !CONFIG_CRASH_DUMP build option is supported
with that, it led to the below warning:

  "WARN: resolve_btfids: unresolved symbol crash_kexec"

Fix it by using the appropriate #ifdef.

[1] https://lore.kernel.org/all/20240124051254.67105-1-bhe@redhat.com/

Acked-by: Baoquan He <bhe@redhat.com>
Fixes: 02aff8480533 ("crash: split crash dumping code out from kexec_core.c")
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Link: https://lore.kernel.org/r/20240319080152.36987-1-hbathini@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-27 08:52:24 -07:00
Jakub Kicinski
2a702c2e57 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-03-25

We've added 38 non-merge commits during the last 13 day(s) which contain
a total of 50 files changed, 867 insertions(+), 274 deletions(-).

The main changes are:

1) Add the ability to specify and retrieve BPF cookie also for raw
   tracepoint programs in order to ease migration from classic to raw
   tracepoints, from Andrii Nakryiko.

2) Allow the use of bpf_get_{ns_,}current_pid_tgid() helper for all
   program types and add additional BPF selftests, from Yonghong Song.

3) Several improvements to bpftool and its build, for example, enabling
   libbpf logs when loading pid_iter in debug mode, from Quentin Monnet.

4) Check the return code of all BPF-related set_memory_*() functions during
   load and bail out in case they fail, from Christophe Leroy.

5) Avoid a goto in regs_refine_cond_op() such that the verifier can
   be better integrated into Agni tool which doesn't support backedges
   yet, from Harishankar Vishwanathan.

6) Add a small BPF trie perf improvement by always inlining
   longest_prefix_match, from Jesper Dangaard Brouer.

7) Small BPF selftest refactor in bpf_tcp_ca.c to utilize start_server()
   helper instead of open-coding it, from Geliang Tang.

8) Improve test_tc_tunnel.sh BPF selftest to prevent client connect
   before the server bind, from Alessandro Carminati.

9) Fix BPF selftest benchmark for older glibc and use syscall(SYS_gettid)
   instead of gettid(), from Alan Maguire.

10) Implement a backward-compatible method for struct_ops types with
    additional fields which are not present in older kernels,
    from Kui-Feng Lee.

11) Add a small helper to check if an instruction is addr_space_cast
    from as(0) to as(1) and utilize it in x86-64 JIT, from Puranjay Mohan.

12) Small cleanup to remove unnecessary error check in
    bpf_struct_ops_map_update_elem, from Martin KaFai Lau.

13) Improvements to libbpf fd validity checks for BPF map/programs,
    from Mykyta Yatsenko.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (38 commits)
  selftests/bpf: Fix flaky test btf_map_in_map/lookup_update
  bpf: implement insn_is_cast_user() helper for JITs
  bpf: Avoid get_kernel_nofault() to fetch kprobe entry IP
  selftests/bpf: Use start_server in bpf_tcp_ca
  bpf: Sync uapi bpf.h to tools directory
  libbpf: Add new sec_def "sk_skb/verdict"
  selftests/bpf: Mark uprobe trigger functions with nocf_check attribute
  selftests/bpf: Use syscall(SYS_gettid) instead of gettid() wrapper in bench
  bpf-next: Avoid goto in regs_refine_cond_op()
  bpftool: Clean up HOST_CFLAGS, HOST_LDFLAGS for bootstrap bpftool
  selftests/bpf: scale benchmark counting by using per-CPU counters
  bpftool: Remove unnecessary source files from bootstrap version
  bpftool: Enable libbpf logs when loading pid_iter in debug mode
  selftests/bpf: add raw_tp/tp_btf BPF cookie subtests
  libbpf: add support for BPF cookie for raw_tp/tp_btf programs
  bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs
  bpf: pass whole link instead of prog when triggering raw tracepoint
  bpf: flatten bpf_probe_register call chain
  selftests/bpf: Prevent client connect before server bind in test_tc_tunnel.sh
  selftests/bpf: Add a sk_msg prog bpf_get_ns_current_pid_tgid() test
  ...
====================

Link: https://lore.kernel.org/r/20240325233940.7154-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-27 07:52:34 -07:00
Paolo Abeni
37ccdf7f11 bpf-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2024-03-25

The following pull-request contains BPF updates for your *net* tree.

We've added 17 non-merge commits during the last 12 day(s) which contain
a total of 19 files changed, 184 insertions(+), 61 deletions(-).

The main changes are:

1) Fix an arm64 BPF JIT bug in BPF_LDX_MEMSX implementation's offset handling
   found via test_bpf module, from Puranjay Mohan.

2) Various fixups to the BPF arena code in particular in the BPF verifier and
   around BPF selftests to match latest corresponding LLVM implementation,
   from Puranjay Mohan and Alexei Starovoitov.

3) Fix xsk to not assume that metadata is always requested in TX completion,
   from Stanislav Fomichev.

4) Fix riscv BPF JIT's kfunc parameter incompatibility between BPF and the riscv
   ABI which requires sign-extension on int/uint, from Pu Lehui.

5) Fix s390x BPF JIT's bpf_plt pointer arithmetic which triggered a crash when
   testing struct_ops, from Ilya Leoshkevich.

6) Fix libbpf's arena mmap handling which had incorrect u64-to-pointer cast on
   32-bit architectures, from Andrii Nakryiko.

7) Fix libbpf to define MFD_CLOEXEC when not available, from Arnaldo Carvalho de Melo.

8) Fix arm64 BPF JIT implementation for 32bit unconditional bswap which
   resulted in an incorrect swap as indicated by test_bpf, from Artem Savkov.

9) Fix BPF man page build script to use silent mode, from Hangbin Liu.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  riscv, bpf: Fix kfunc parameters incompatibility between bpf and riscv abi
  bpf: verifier: reject addr_space_cast insn without arena
  selftests/bpf: verifier_arena: fix mmap address for arm64
  bpf: verifier: fix addr_space_cast from as(1) to as(0)
  libbpf: Define MFD_CLOEXEC if not available
  arm64: bpf: fix 32bit unconditional bswap
  bpf, arm64: fix bug in BPF_LDX_MEMSX
  libbpf: fix u64-to-pointer cast on 32-bit arches
  s390/bpf: Fix bpf_plt pointer arithmetic
  xsk: Don't assume metadata is always requested in TX completion
  selftests/bpf: Add arena test case for 4Gbyte corner case
  selftests/bpf: Remove hard coded PAGE_SIZE macro.
  libbpf, selftests/bpf: Adjust libbpf, bpftool, selftests to match LLVM
  bpf: Clarify bpf_arena comments.
  MAINTAINERS: Update email address for Quentin Monnet
  scripts/bpf_doc: Use silent mode when exec make cmd
  bpf: Temporarily disable atomic operations in BPF arena
====================

Link: https://lore.kernel.org/r/20240325213520.26688-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-03-26 12:55:18 +01:00
Puranjay Mohan
122fdbd2a0 bpf: verifier: reject addr_space_cast insn without arena
The verifier allows using the addr_space_cast instruction in a program
that doesn't have an associated arena. This was caught in the form an
invalid memory access in do_misc_fixups() when while converting
addr_space_cast to a normal 32-bit mov, env->prog->aux->arena was
dereferenced to check for BPF_F_NO_USER_CONV flag.

Reject programs that include the addr_space_cast instruction but don't
have an associated arena.

root@rv-tester:~# ./reproducer
 Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000030
 Oops [#1]
 [<ffffffff8017eeaa>] do_misc_fixups+0x43c/0x1168
 [<ffffffff801936d6>] bpf_check+0xda8/0x22b6
 [<ffffffff80174b32>] bpf_prog_load+0x486/0x8dc
 [<ffffffff80176566>] __sys_bpf+0xbd8/0x214e
 [<ffffffff80177d14>] __riscv_sys_bpf+0x22/0x2a
 [<ffffffff80d2493a>] do_trap_ecall_u+0x102/0x17c
 [<ffffffff80d3048c>] ret_from_exception+0x0/0x64

Fixes: 6082b6c328b5 ("bpf: Recognize addr_space_cast instruction in the verifier.")
Reported-by: xingwei lee <xrivendell7@gmail.com>
Reported-by: yue sun <samsun1006219@gmail.com>
Closes: https://lore.kernel.org/bpf/CABOYnLz09O1+2gGVJuCxd_24a-7UueXzV-Ff+Fr+h5EKFDiYCQ@mail.gmail.com/
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20240322153518.11555-1-puranjay12@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-22 20:44:09 -07:00
Puranjay Mohan
f7f5d1808b bpf: verifier: fix addr_space_cast from as(1) to as(0)
The verifier currently converts addr_space_cast from as(1) to as(0) that
is: BPF_ALU64 | BPF_MOV | BPF_X with off=1 and imm=1
to
BPF_ALU | BPF_MOV | BPF_X with imm=1 (32-bit mov)

Because of this imm=1, the JITs that have bpf_jit_needs_zext() == true,
interpret the converted instruction as BPF_ZEXT_REG(DST) which is a
special form of mov32, used for doing explicit zero extension on dst.
These JITs will just zero extend the dst reg and will not move the src to
dst before the zext.

Fix do_misc_fixups() to set imm=0 when converting addr_space_cast to a
normal mov32.

The JITs that have bpf_jit_needs_zext() == true rely on the verifier to
emit zext instructions. Mark dst_reg as subreg when doing cast from
as(1) to as(0) so the verifier emits a zext instruction after the mov.

Fixes: 6082b6c328b5 ("bpf: Recognize addr_space_cast instruction in the verifier.")
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20240321153939.113996-1-puranjay12@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-22 20:36:36 -07:00
Harishankar Vishwanathan
4c2a26fc80 bpf-next: Avoid goto in regs_refine_cond_op()
In case of GE/GT/SGE/JST instructions, regs_refine_cond_op()
reuses the logic that does analysis of LE/LT/SLE/SLT instructions.
This commit avoids the use of a goto to perform the reuse.

Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240321002955.808604-1-harishankar.vishwanathan@gmail.com
2024-03-21 11:56:26 -07:00
Yan Zhai
00bf631224 bpf: report RCU QS in cpumap kthread
When there are heavy load, cpumap kernel threads can be busy polling
packets from redirect queues and block out RCU tasks from reaching
quiescent states. It is insufficient to just call cond_resched() in such
context. Periodically raise a consolidated RCU QS before cond_resched
fixes the problem.

Fixes: 6710e1126934 ("bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP")
Reviewed-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://lore.kernel.org/r/c17b9f1517e19d813da3ede5ed33ee18496bb5d8.1710877680.git.yan@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-20 21:05:43 -07:00
Andrii Nakryiko
68ca5d4eeb bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs
Wire up BPF cookie for raw tracepoint programs (both BTF and non-BTF
aware variants). This brings them up to part w.r.t. BPF cookie usage
with classic tracepoint and fentry/fexit programs.

Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-4-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-19 23:05:34 -07:00
Andrii Nakryiko
d4dfc5700e bpf: pass whole link instead of prog when triggering raw tracepoint
Instead of passing prog as an argument to bpf_trace_runX() helpers, that
are called from tracepoint triggering calls, store BPF link itself
(struct bpf_raw_tp_link for raw tracepoints). This will allow to pass
extra information like BPF cookie into raw tracepoint registration.

Instead of replacing `struct bpf_prog *prog = __data;` with
corresponding `struct bpf_raw_tp_link *link = __data;` assignment in
`__bpf_trace_##call` I just passed `__data` through into underlying
bpf_trace_runX() call. This works well because we implicitly cast `void *`,
and it also avoids naming clashes with arguments coming from
tracepoint's "proto" list. We could have run into the same problem with
"prog", we just happened to not have a tracepoint that has "prog" input
argument. We are less lucky with "link", as there are tracepoints using
"link" argument name already. So instead of trying to avoid naming
conflicts, let's just remove intermediate local variable. It doesn't
hurt readibility, it's either way a bit of a maze of calls and macros,
that requires careful reading.

Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-3-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-19 23:05:33 -07:00
Yonghong Song
eb166e522c bpf: Allow helper bpf_get_[ns_]current_pid_tgid() for all prog types
Currently bpf_get_current_pid_tgid() is allowed in tracing, cgroup
and sk_msg progs while bpf_get_ns_current_pid_tgid() is only allowed
in tracing progs.

We have an internal use case where for an application running
in a container (with pid namespace), user wants to get
the pid associated with the pid namespace in a cgroup bpf
program. Currently, cgroup bpf progs already allow
bpf_get_current_pid_tgid(). Let us allow bpf_get_ns_current_pid_tgid()
as well.

With auditing the code, bpf_get_current_pid_tgid() is also used
by sk_msg prog. But there are no side effect to expose these two
helpers to all prog types since they do not reveal any kernel specific
data. The detailed discussion is in [1].

So with this patch, both bpf_get_current_pid_tgid() and bpf_get_ns_current_pid_tgid()
are put in bpf_base_func_proto(), making them available to all
program types.

  [1] https://lore.kernel.org/bpf/20240307232659.1115872-1-yonghong.song@linux.dev/

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240315184854.2975190-1-yonghong.song@linux.dev
2024-03-19 14:24:07 -07:00