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Add a simple routing table, and a couple of route output handlers, and
the mctp packet_type & handler.
Includes changes from Matt Johnston <matt@codeconstruct.com.au>.
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change adds the infrastructure for managing MCTP netdevices; we add
a pointer to the AF_MCTP-specific data to struct netdevice, and hook up
the rtnetlink operations for adding and removing addresses.
Includes changes from Matt Johnston <matt@codeconstruct.com.au>.
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add an empty drivers/net/mctp/, for future interface drivers.
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change introduces the user-visible MCTP header, containing the
protocol-specific addressing definitions.
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Simple packet header format as defined by DMTF DSP0236.
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add an empty socket implementation, plus initialisation/destruction
handlers.
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add basic Kconfig, an initial (empty) af_mctp source object, and
{AF,PF}_MCTP definitions, and the required definitions for a new
protocol type.
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
File-scope struct nfcmrvl_if_ops is not modified so can be made const.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several functions do not modify pointed data so arguments and local
variables can be const for correctness and safety.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several functions do not modify pointed data so arguments and local
variables can be const for correctness and safety.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several functions do not modify pointed data so arguments and local
variables can be const for correctness and safety. This allows also
making file-scope nci_core_get_config_otp_ram_version array const.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Loop iterators are simple integers, no point to optimize the size and
use u8. It only raises the question whether the variable is used in
some other context.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Size of firmware is a type of size_t, so print it directly instead of
casting to int.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
nfcsim_abort_cmd() does not modify struct nfcsim, so local variable
can be a pointer to const.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
virtual_ncidev_ioctl() does not modify struct nfc_dev, so local variable
can be a pointer to const.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several functions do not modify pointed data so arguments and local
variables can be const for correctness and safety.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several functions do not modify pointed data so arguments and local
variables can be const for correctness and safety.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The buffer passed to mei_nfc_send() can be const for correctness and
safety.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The struct nfc_dev is not modified by nfc_get_drvdata() and
nfc_device_name() so it can be made a const.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Paolo Abeni says:
====================
sk_buff: optimize GRO for the common case
This is a trimmed down revision of "sk_buff: optimize layout for GRO",
specifically dropping the changes to the sk_buff layout[1].
This series tries to accomplish 2 goals:
- optimize the GRO stage for the most common scenario, avoiding a bunch
of conditional and some more code
- let owned skbs entering the GRO engine, allowing backpressure in the
veth GRO forward path.
A new sk_buff flag (!!!) is introduced and maintained for GRO's sake.
Such field uses an existing hole, so there is no change to the sk_buff
size.
[1] two main reasons:
- move skb->inner_ field requires some extra care, as some in kernel
users access and the fields regardless of skb->encapsulation.
- extending secmark size clash with ct and nft uAPIs
address the all above is possible, I think, but for sure not in a single
series.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Leveraging the previous patch we can now avoid orphaning the
skb in the veth gro path, allowing correct backpressure.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change leverages the infrastructure introduced by the previous
patches to allow soft devices passing to the GRO engine owned skbs
without impacting the fast-path.
It's up to the GRO caller ensuring the slow_gro bit validity before
invoking the GRO engine. The new helper skb_prepare_for_gro() is
introduced for that goal.
On slow_gro, skbs are aggregated only with equal sk.
Additionally, skb truesize on GRO recycle and free is correctly
updated so that sk wmem is not changed by the GRO processing.
rfc-> v1:
- fixed bad truesize on dev_gro_receive NAPI_FREE
- use the existing state bit
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After the previous patches, at GRO time, skb->slow_gro is
usually 0, unless the packets comes from some H/W offload
slowpath or tunnel.
We can optimize the GRO code assuming !skb->slow_gro is likely.
This remove multiple conditionals in the most common path, at the
price of an additional one when we hit the above "slow-paths".
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to the previous one, but tracking the
active_extensions field status.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to the previous patch, but covering the dst field:
the slow_gro flag is additionally set when a dst is attached
to the skb
RFC -> v1:
- use the existing flag instead of adding a new one
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The new flag tracks if any state field is set, so that
GRO requires 'unusual'/slow prepare steps.
Set such flag when a ct entry is attached to the skb,
and never clear it.
The new bit uses an existing hole into the sk_buff struct
RFC -> v1:
- use a single state bit, never clear it
- avoid moving the _nfct field
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Building with -Warray-bounds on systems with 64K pages there's a
warning:
fs/btrfs/disk-io.c: In function ‘csum_tree_block’:
fs/btrfs/disk-io.c:226:34: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds]
226 | kaddr = page_address(buf->pages[i]);
| ~~~~~~~~~~^~~
./include/linux/mm.h:1630:48: note: in definition of macro ‘page_address’
1630 | #define page_address(page) lowmem_page_address(page)
| ^~~~
In file included from fs/btrfs/ctree.h:32,
from fs/btrfs/disk-io.c:23:
fs/btrfs/extent_io.h:98:15: note: while referencing ‘pages’
98 | struct page *pages[1];
| ^~~~~
The compiler has no way to know that in that case the nodesize is exactly
PAGE_SIZE, so the resulting number of pages will be correct (1).
Let's use num_extent_pages that makes the case nodesize == PAGE_SIZE
explicitly 1.
Reported-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit fixes a functional regression introduced by the commit 82f09a637dd3
("HID: ft260: improve error handling of ft260_hid_feature_report_get()")
when upon USB disconnect, the FTDI FT260 i2c device is still available within
the /dev folder.
In my company's product, where the host USB to FT260 USB connection is
hard-wired in the PCB, the issue is not reproducible. To reproduce it, I used
the VirtualBox Ubuntu 20.04 VM and the UMFT260EV1A development module for the
FTDI FT260 chip:
Plug the UMFT260EV1A module into a USB port and attach it to VM.
The VM shows 2 i2c devices under the /dev:
michael@michael-VirtualBox:~$ ls /dev/i2c-*
/dev/i2c-0 /dev/i2c-1
The i2c-0 is not related to the FTDI FT260:
michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-0/name
SMBus PIIX4 adapter at 4100
The i2c-1 is created by hid-ft260.ko:
michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-1/name
FT260 usb-i2c bridge on hidraw1
Now, detach the FTDI FT260 USB device from VM. We expect the /dev/i2c-1
to disappear, but it's still here:
michael@michael-VirtualBox:~$ ls /dev/i2c-*
/dev/i2c-0 /dev/i2c-1
And the kernel log shows:
[ +0.001202] usb 2-2: USB disconnect, device number 3
[ +0.000109] ft260 0003:0403:6030.0002: failed to retrieve system status
[ +0.000316] ft260 0003:0403:6030.0003: failed to retrieve system status
It happens because the commit 82f09a637dd3 changed the ft260_get_system_config()
return logic. This caused the ft260_is_interface_enabled() to exit with error
upon the FT260 device USB disconnect, which in turn, aborted the ft260_remove()
before deleting the FT260 i2c device and cleaning its sysfs stuff.
This commit restores the FT260 USB removal functionality and improves the
ft260_is_interface_enabled() code to handle correctly all chip modes defined
by the device interface configuration pins DCNF0 and DCNF1.
Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Acked-by: Aaron Jones (FTDI-UK) <aaron.jones@ftdichip.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The memory reserved by console/PALcode or non-volatile memory is not added
to memblock.memory.
Since commit fa3354e4ea39 (mm: free_area_init: use maximal zone PFNs rather
than zone sizes) the initialization of the memory map relies on the
accuracy of memblock.memory to properly calculate zone sizes. The holes in
memblock.memory caused by absent regions reserved by the firmware cause
incorrect initialization of struct pages which leads to BUG() during the
initial page freeing:
BUG: Bad page state in process swapper pfn:2ffc53
page:fffffc000ecf14c0 refcount:0 mapcount:1 mapping:0000000000000000 index:0x0
flags: 0x0()
raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
page dumped because: nonzero mapcount
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 5.7.0-03841-gfa3354e4ea39-dirty #26
fffffc0001b5bd68 fffffc0001b5be80 fffffc00011cd148 fffffc000ecf14c0
fffffc00019803df fffffc0001b5be80 fffffc00011ce340 fffffc000ecf14c0
0000000000000000 fffffc0001b5be80 fffffc0001b482c0 fffffc00027d6618
fffffc00027da7d0 00000000002ff97a 0000000000000000 fffffc0001b5be80
fffffc00011d1abc fffffc000ecf14c0 fffffc0002d00000 fffffc0001b5be80
fffffc0001b2350c 0000000000300000 fffffc0001b48298 fffffc0001b482c0
Trace:
[<fffffc00011cd148>] bad_page+0x168/0x1b0
[<fffffc00011ce340>] free_pcp_prepare+0x1e0/0x290
[<fffffc00011d1abc>] free_unref_page+0x2c/0xa0
[<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30
[<fffffc00014ee5f0>] cmp_ex_sort+0x0/0x30
[<fffffc000101001c>] _stext+0x1c/0x20
Fix this by registering the reserved ranges in memblock.memory.
Link: https://lore.kernel.org/lkml/20210726192311.uffqnanxw3ac5wwi@ivybridge
Fixes: fa3354e4ea39 ("mm: free_area_init: use maximal zone PFNs rather than zone sizes")
Reported-by: Matt Turner <mattst88@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
- Fix vbt port mask
- Fix around reading the right DSC disable fuse in display_ver 10
- Split display version 9 and 10 in intel_setup_outputs
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Merge tag 'drm-intel-fixes-2021-07-28' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes
Display related fixes:
- Fix vbt port mask
- Fix around reading the right DSC disable fuse in display_ver 10
- Split display version 9 and 10 in intel_setup_outputs
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/YQF63ruuE72x2T45@intel.com
Daniel Borkmann says:
====================
pull-request: bpf 2021-07-29
The following pull-request contains BPF updates for your *net* tree.
We've added 9 non-merge commits during the last 14 day(s) which contain
a total of 20 files changed, 446 insertions(+), 138 deletions(-).
The main changes are:
1) Fix UBSAN out-of-bounds splat for showing XDP link fdinfo, from Lorenz Bauer.
2) Fix insufficient Spectre v4 mitigation in BPF runtime, from Daniel Borkmann,
Piotr Krysiuk and Benedict Schlueter.
3) Batch of fixes for BPF sockmap found under stress testing, from John Fastabend.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Spectre v4 gadgets make use of memory disambiguation, which is a set of
techniques that execute memory access instructions, that is, loads and
stores, out of program order; Intel's optimization manual, section 2.4.4.5:
A load instruction micro-op may depend on a preceding store. Many
microarchitectures block loads until all preceding store addresses are
known. The memory disambiguator predicts which loads will not depend on
any previous stores. When the disambiguator predicts that a load does
not have such a dependency, the load takes its data from the L1 data
cache. Eventually, the prediction is verified. If an actual conflict is
detected, the load and all succeeding instructions are re-executed.
af86ca4e3088 ("bpf: Prevent memory disambiguation attack") tried to mitigate
this attack by sanitizing the memory locations through preemptive "fast"
(low latency) stores of zero prior to the actual "slow" (high latency) store
of a pointer value such that upon dependency misprediction the CPU then
speculatively executes the load of the pointer value and retrieves the zero
value instead of the attacker controlled scalar value previously stored at
that location, meaning, subsequent access in the speculative domain is then
redirected to the "zero page".
The sanitized preemptive store of zero prior to the actual "slow" store is
done through a simple ST instruction based on r10 (frame pointer) with
relative offset to the stack location that the verifier has been tracking
on the original used register for STX, which does not have to be r10. Thus,
there are no memory dependencies for this store, since it's only using r10
and immediate constant of zero; hence af86ca4e3088 /assumed/ a low latency
operation.
However, a recent attack demonstrated that this mitigation is not sufficient
since the preemptive store of zero could also be turned into a "slow" store
and is thus bypassed as well:
[...]
// r2 = oob address (e.g. scalar)
// r7 = pointer to map value
31: (7b) *(u64 *)(r10 -16) = r2
// r9 will remain "fast" register, r10 will become "slow" register below
32: (bf) r9 = r10
// JIT maps BPF reg to x86 reg:
// r9 -> r15 (callee saved)
// r10 -> rbp
// train store forward prediction to break dependency link between both r9
// and r10 by evicting them from the predictor's LRU table.
33: (61) r0 = *(u32 *)(r7 +24576)
34: (63) *(u32 *)(r7 +29696) = r0
35: (61) r0 = *(u32 *)(r7 +24580)
36: (63) *(u32 *)(r7 +29700) = r0
37: (61) r0 = *(u32 *)(r7 +24584)
38: (63) *(u32 *)(r7 +29704) = r0
39: (61) r0 = *(u32 *)(r7 +24588)
40: (63) *(u32 *)(r7 +29708) = r0
[...]
543: (61) r0 = *(u32 *)(r7 +25596)
544: (63) *(u32 *)(r7 +30716) = r0
// prepare call to bpf_ringbuf_output() helper. the latter will cause rbp
// to spill to stack memory while r13/r14/r15 (all callee saved regs) remain
// in hardware registers. rbp becomes slow due to push/pop latency. below is
// disasm of bpf_ringbuf_output() helper for better visual context:
//
// ffffffff8117ee20: 41 54 push r12
// ffffffff8117ee22: 55 push rbp
// ffffffff8117ee23: 53 push rbx
// ffffffff8117ee24: 48 f7 c1 fc ff ff ff test rcx,0xfffffffffffffffc
// ffffffff8117ee2b: 0f 85 af 00 00 00 jne ffffffff8117eee0 <-- jump taken
// [...]
// ffffffff8117eee0: 49 c7 c4 ea ff ff ff mov r12,0xffffffffffffffea
// ffffffff8117eee7: 5b pop rbx
// ffffffff8117eee8: 5d pop rbp
// ffffffff8117eee9: 4c 89 e0 mov rax,r12
// ffffffff8117eeec: 41 5c pop r12
// ffffffff8117eeee: c3 ret
545: (18) r1 = map[id:4]
547: (bf) r2 = r7
548: (b7) r3 = 0
549: (b7) r4 = 4
550: (85) call bpf_ringbuf_output#194288
// instruction 551 inserted by verifier \
551: (7a) *(u64 *)(r10 -16) = 0 | /both/ are now slow stores here
// storing map value pointer r7 at fp-16 | since value of r10 is "slow".
552: (7b) *(u64 *)(r10 -16) = r7 /
// following "fast" read to the same memory location, but due to dependency
// misprediction it will speculatively execute before insn 551/552 completes.
553: (79) r2 = *(u64 *)(r9 -16)
// in speculative domain contains attacker controlled r2. in non-speculative
// domain this contains r7, and thus accesses r7 +0 below.
554: (71) r3 = *(u8 *)(r2 +0)
// leak r3
As can be seen, the current speculative store bypass mitigation which the
verifier inserts at line 551 is insufficient since /both/, the write of
the zero sanitation as well as the map value pointer are a high latency
instruction due to prior memory access via push/pop of r10 (rbp) in contrast
to the low latency read in line 553 as r9 (r15) which stays in hardware
registers. Thus, architecturally, fp-16 is r7, however, microarchitecturally,
fp-16 can still be r2.
Initial thoughts to address this issue was to track spilled pointer loads
from stack and enforce their load via LDX through r10 as well so that /both/
the preemptive store of zero /as well as/ the load use the /same/ register
such that a dependency is created between the store and load. However, this
option is not sufficient either since it can be bypassed as well under
speculation. An updated attack with pointer spill/fills now _all_ based on
r10 would look as follows:
[...]
// r2 = oob address (e.g. scalar)
// r7 = pointer to map value
[...]
// longer store forward prediction training sequence than before.
2062: (61) r0 = *(u32 *)(r7 +25588)
2063: (63) *(u32 *)(r7 +30708) = r0
2064: (61) r0 = *(u32 *)(r7 +25592)
2065: (63) *(u32 *)(r7 +30712) = r0
2066: (61) r0 = *(u32 *)(r7 +25596)
2067: (63) *(u32 *)(r7 +30716) = r0
// store the speculative load address (scalar) this time after the store
// forward prediction training.
2068: (7b) *(u64 *)(r10 -16) = r2
// preoccupy the CPU store port by running sequence of dummy stores.
2069: (63) *(u32 *)(r7 +29696) = r0
2070: (63) *(u32 *)(r7 +29700) = r0
2071: (63) *(u32 *)(r7 +29704) = r0
2072: (63) *(u32 *)(r7 +29708) = r0
2073: (63) *(u32 *)(r7 +29712) = r0
2074: (63) *(u32 *)(r7 +29716) = r0
2075: (63) *(u32 *)(r7 +29720) = r0
2076: (63) *(u32 *)(r7 +29724) = r0
2077: (63) *(u32 *)(r7 +29728) = r0
2078: (63) *(u32 *)(r7 +29732) = r0
2079: (63) *(u32 *)(r7 +29736) = r0
2080: (63) *(u32 *)(r7 +29740) = r0
2081: (63) *(u32 *)(r7 +29744) = r0
2082: (63) *(u32 *)(r7 +29748) = r0
2083: (63) *(u32 *)(r7 +29752) = r0
2084: (63) *(u32 *)(r7 +29756) = r0
2085: (63) *(u32 *)(r7 +29760) = r0
2086: (63) *(u32 *)(r7 +29764) = r0
2087: (63) *(u32 *)(r7 +29768) = r0
2088: (63) *(u32 *)(r7 +29772) = r0
2089: (63) *(u32 *)(r7 +29776) = r0
2090: (63) *(u32 *)(r7 +29780) = r0
2091: (63) *(u32 *)(r7 +29784) = r0
2092: (63) *(u32 *)(r7 +29788) = r0
2093: (63) *(u32 *)(r7 +29792) = r0
2094: (63) *(u32 *)(r7 +29796) = r0
2095: (63) *(u32 *)(r7 +29800) = r0
2096: (63) *(u32 *)(r7 +29804) = r0
2097: (63) *(u32 *)(r7 +29808) = r0
2098: (63) *(u32 *)(r7 +29812) = r0
// overwrite scalar with dummy pointer; same as before, also including the
// sanitation store with 0 from the current mitigation by the verifier.
2099: (7a) *(u64 *)(r10 -16) = 0 | /both/ are now slow stores here
2100: (7b) *(u64 *)(r10 -16) = r7 | since store unit is still busy.
// load from stack intended to bypass stores.
2101: (79) r2 = *(u64 *)(r10 -16)
2102: (71) r3 = *(u8 *)(r2 +0)
// leak r3
[...]
Looking at the CPU microarchitecture, the scheduler might issue loads (such
as seen in line 2101) before stores (line 2099,2100) because the load execution
units become available while the store execution unit is still busy with the
sequence of dummy stores (line 2069-2098). And so the load may use the prior
stored scalar from r2 at address r10 -16 for speculation. The updated attack
may work less reliable on CPU microarchitectures where loads and stores share
execution resources.
This concludes that the sanitizing with zero stores from af86ca4e3088 ("bpf:
Prevent memory disambiguation attack") is insufficient. Moreover, the detection
of stack reuse from af86ca4e3088 where previously data (STACK_MISC) has been
written to a given stack slot where a pointer value is now to be stored does
not have sufficient coverage as precondition for the mitigation either; for
several reasons outlined as follows:
1) Stack content from prior program runs could still be preserved and is
therefore not "random", best example is to split a speculative store
bypass attack between tail calls, program A would prepare and store the
oob address at a given stack slot and then tail call into program B which
does the "slow" store of a pointer to the stack with subsequent "fast"
read. From program B PoV such stack slot type is STACK_INVALID, and
therefore also must be subject to mitigation.
2) The STACK_SPILL must not be coupled to register_is_const(&stack->spilled_ptr)
condition, for example, the previous content of that memory location could
also be a pointer to map or map value. Without the fix, a speculative
store bypass is not mitigated in such precondition and can then lead to
a type confusion in the speculative domain leaking kernel memory near
these pointer types.
While brainstorming on various alternative mitigation possibilities, we also
stumbled upon a retrospective from Chrome developers [0]:
[...] For variant 4, we implemented a mitigation to zero the unused memory
of the heap prior to allocation, which cost about 1% when done concurrently
and 4% for scavenging. Variant 4 defeats everything we could think of. We
explored more mitigations for variant 4 but the threat proved to be more
pervasive and dangerous than we anticipated. For example, stack slots used
by the register allocator in the optimizing compiler could be subject to
type confusion, leading to pointer crafting. Mitigating type confusion for
stack slots alone would have required a complete redesign of the backend of
the optimizing compiler, perhaps man years of work, without a guarantee of
completeness. [...]
From BPF side, the problem space is reduced, however, options are rather
limited. One idea that has been explored was to xor-obfuscate pointer spills
to the BPF stack:
[...]
// preoccupy the CPU store port by running sequence of dummy stores.
[...]
2106: (63) *(u32 *)(r7 +29796) = r0
2107: (63) *(u32 *)(r7 +29800) = r0
2108: (63) *(u32 *)(r7 +29804) = r0
2109: (63) *(u32 *)(r7 +29808) = r0
2110: (63) *(u32 *)(r7 +29812) = r0
// overwrite scalar with dummy pointer; xored with random 'secret' value
// of 943576462 before store ...
2111: (b4) w11 = 943576462
2112: (af) r11 ^= r7
2113: (7b) *(u64 *)(r10 -16) = r11
2114: (79) r11 = *(u64 *)(r10 -16)
2115: (b4) w2 = 943576462
2116: (af) r2 ^= r11
// ... and restored with the same 'secret' value with the help of AX reg.
2117: (71) r3 = *(u8 *)(r2 +0)
[...]
While the above would not prevent speculation, it would make data leakage
infeasible by directing it to random locations. In order to be effective
and prevent type confusion under speculation, such random secret would have
to be regenerated for each store. The additional complexity involved for a
tracking mechanism that prevents jumps such that restoring spilled pointers
would not get corrupted is not worth the gain for unprivileged. Hence, the
fix in here eventually opted for emitting a non-public BPF_ST | BPF_NOSPEC
instruction which the x86 JIT translates into a lfence opcode. Inserting the
latter in between the store and load instruction is one of the mitigations
options [1]. The x86 instruction manual notes:
[...] An LFENCE that follows an instruction that stores to memory might
complete before the data being stored have become globally visible. [...]
The latter meaning that the preceding store instruction finished execution
and the store is at minimum guaranteed to be in the CPU's store queue, but
it's not guaranteed to be in that CPU's L1 cache at that point (globally
visible). The latter would only be guaranteed via sfence. So the load which
is guaranteed to execute after the lfence for that local CPU would have to
rely on store-to-load forwarding. [2], in section 2.3 on store buffers says:
[...] For every store operation that is added to the ROB, an entry is
allocated in the store buffer. This entry requires both the virtual and
physical address of the target. Only if there is no free entry in the store
buffer, the frontend stalls until there is an empty slot available in the
store buffer again. Otherwise, the CPU can immediately continue adding
subsequent instructions to the ROB and execute them out of order. On Intel
CPUs, the store buffer has up to 56 entries. [...]
One small upside on the fix is that it lifts constraints from af86ca4e3088
where the sanitize_stack_off relative to r10 must be the same when coming
from different paths. The BPF_ST | BPF_NOSPEC gets emitted after a BPF_STX
or BPF_ST instruction. This happens either when we store a pointer or data
value to the BPF stack for the first time, or upon later pointer spills.
The former needs to be enforced since otherwise stale stack data could be
leaked under speculation as outlined earlier. For non-x86 JITs the BPF_ST |
BPF_NOSPEC mapping is currently optimized away, but others could emit a
speculation barrier as well if necessary. For real-world unprivileged
programs e.g. generated by LLVM, pointer spill/fill is only generated upon
register pressure and LLVM only tries to do that for pointers which are not
used often. The program main impact will be the initial BPF_ST | BPF_NOSPEC
sanitation for the STACK_INVALID case when the first write to a stack slot
occurs e.g. upon map lookup. In future we might refine ways to mitigate
the latter cost.
[0] https://arxiv.org/pdf/1902.05178.pdf
[1] https://msrc-blog.microsoft.com/2018/05/21/analysis-and-mitigation-of-speculative-store-bypass-cve-2018-3639/
[2] https://arxiv.org/pdf/1905.05725.pdf
Fixes: af86ca4e3088 ("bpf: Prevent memory disambiguation attack")
Fixes: f7cf25b2026d ("bpf: track spill/fill of constants")
Co-developed-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
In case of JITs, each of the JIT backends compiles the BPF nospec instruction
/either/ to a machine instruction which emits a speculation barrier /or/ to
/no/ machine instruction in case the underlying architecture is not affected
by Speculative Store Bypass or has different mitigations in place already.
This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence'
instruction for mitigation. In case of arm64, we rely on the firmware mitigation
as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled,
it works for all of the kernel code with no need to provide any additional
instructions here (hence only comment in arm64 JIT). Other archs can follow
as needed. The BPF nospec instruction is specifically targeting Spectre v4
since i) we don't use a serialization barrier for the Spectre v1 case, and
ii) mitigation instructions for v1 and v4 might be different on some archs.
The BPF nospec is required for a future commit, where the BPF verifier does
annotate intermediate BPF programs with speculation barriers.
Co-developed-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Append ioam6-sysctl to toctree in order to get rid of building warnings.
Signed-off-by: Hu Haowen <src.res@email.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently there are issues when adding a bridge FDB entry as VLAN-aware
and deleting it as VLAN-unaware, or vice versa.
However this is an unneeded complication, since the bridge always
installs its default FDB entries in VLAN 0 to match on VLAN-unaware
ports, and in the default_pvid (VLAN 1) to match on VLAN-aware ports.
So instead of trying to outsmart the bridge, just install all entries it
gives us, and they will start matching packets when the vlan_filtering
mode changes.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the following script:
1. ip link add br0 type bridge vlan_filtering 1 && ip link set br0 up
2. ip link set swp2 up && ip link set swp2 master br0
3. ip link set swp3 up && ip link set swp3 master br0
4. ip link set swp4 up && ip link set swp4 master br0
5. bridge vlan del dev swp2 vid 1
6. bridge vlan del dev swp3 vid 1
7. ip link set swp4 nomaster
8. ip link set swp3 nomaster
produces the following output:
[ 641.010738] sja1105 spi0.1: port 2 failed to delete 00:1f:7b:63:02:48 vid 1 from fdb: -2
[ swp2, swp3 and br0 all have the same MAC address, the one listed above ]
In short, this happens because the number of FDB entry additions
notified to switchdev is unbalanced with the number of deletions.
At step 1, the bridge has a random MAC address. At step 2, the
br_fdb_replay of swp2 receives this initial MAC address. Then the bridge
inherits the MAC address of swp2 via br_fdb_change_mac_address(), and it
notifies switchdev (only swp2 at this point) of the deletion of the
random MAC address and the addition of 00:1f:7b:63:02:48 as a local FDB
entry with fdb->dst == swp2, in VLANs 0 and the default_pvid (1).
During step 7:
del_nbp
-> br_fdb_delete_by_port(br, p, vid=0, do_all=1);
-> fdb_delete_local(br, p, f);
br_fdb_delete_by_port() deletes all entries towards the ports,
regardless of vid, because do_all is 1.
fdb_delete_local() has logic to migrate local FDB entries deleted from
one port to another port which shares the same MAC address and is in the
same VLAN, or to the bridge device itself. This migration happens
without notifying switchdev of the deletion on the old port and the
addition on the new one, just fdb->dst is changed and the added_by_user
flag is cleared.
In the example above, the del_nbp(swp4) causes the
"addr 00:1f:7b:63:02:48 vid 1" local FDB entry with fdb->dst == swp4
that existed up until then to be migrated directly towards the bridge
(fdb->dst == NULL). This is because it cannot be migrated to any of the
other ports (swp2 and swp3 are not in VLAN 1).
After the migration to br0 takes place, swp4 requests a deletion replay
of all FDB entries. Since the "addr 00:1f:7b:63:02:48 vid 1" entry now
point towards the bridge, a deletion of it is replayed. There was just
a prior addition of this address, so the switchdev driver deletes this
entry.
Then, the del_nbp(swp3) at step 8 triggers another br_fdb_replay, and
switchdev is notified again to delete "addr 00:1f:7b:63:02:48 vid 1".
But it can't because it no longer has it, so it returns -ENOENT.
There are other possibilities to trigger this issue, but this is by far
the simplest to explain.
To fix this, we must avoid the situation where the addition of an FDB
entry is notified to switchdev as a local entry on a port, and the
deletion is notified on the bridge itself.
Considering that the 2 types of FDB entries are completely equivalent
and we cannot have the same MAC address as a local entry on 2 bridge
ports, or on a bridge port and pointing towards the bridge at the same
time, it makes sense to hide away from switchdev completely the fact
that a local FDB entry is associated with a given bridge port at all.
Just say that it points towards the bridge, it should make no difference
whatsoever to the switchdev driver and should even lead to a simpler
overall implementation, will less cases to handle.
This also avoids any modification at all to the core bridge driver, just
what is reported to switchdev changes. With the local/permanent entries
on bridge ports being already reported to user space, it is hard to
believe that the bridge behavior can change in any backwards-incompatible
way such as making all local FDB entries point towards the bridge.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently when a switchdev port joins a bridge, we replay all FDB
entries pointing towards that port or towards the bridge.
However, this is insufficient in certain situations:
(a) DSA, through its assisted_learning_on_cpu_port logic, snoops
dynamically learned FDB entries on foreign interfaces.
These are FDB entries that are pointing neither towards the newly
joined switchdev port, nor towards the bridge. So these addresses
would be missed when joining a bridge where a foreign interface has
already learned some addresses, and they would also linger on if the
DSA port leaves the bridge before the foreign interface forgets them.
None of this happens if we replay the entire FDB when the port joins.
(b) There is a desire to treat local FDB entries on a port (i.e. the
port's termination MAC address) identically to FDB entries pointing
towards the bridge itself. More details on the reason behind this in
the next patch. The point is that this cannot be done given the
current structure of br_fdb_replay() in this situation:
ip link set swp0 master br0 # br0 inherits its MAC address from swp0
ip link set swp1 master br0
What is desirable is that when swp1 joins the bridge, br_fdb_replay()
also notifies swp1 of br0's MAC address, but this won't in fact
happen because the MAC address of br0 does not have fdb->dst == NULL
(it doesn't point towards the bridge), but it has fdb->dst == swp0.
So our current logic makes it impossible for that address to be
replayed. But if we dump the entire FDB instead of just the entries
with fdb->dst == swp1 and fdb->dst == NULL, then the inherited MAC
address of br0 will be replayed too, which is what we need.
A natural question arises: say there is an FDB entry to be replayed,
like a MAC address dynamically learned on a foreign interface that
belongs to a bridge where no switchdev port has joined yet. If 10
switchdev ports belonging to the same driver join this bridge, one by
one, won't every port get notified 10 times of the foreign FDB entry,
amounting to a total of 100 notifications for this FDB entry in the
switchdev driver?
Well, yes, but this is where the "void *ctx" argument for br_fdb_replay
is useful: every port of the switchdev driver is notified whenever any
other port requests an FDB replay, but because the replay was initiated
by a different port, its context is different from the initiating port's
context, so it ignores those replays.
So the foreign FDB entry will be installed only 10 times, once per port.
This is done so that the following 4 code paths are always well balanced:
(a) addition of foreign FDB entry is replayed when port joins bridge
(b) deletion of foreign FDB entry is replayed when port leaves bridge
(c) addition of foreign FDB entry is notified to all ports currently in bridge
(c) deletion of foreign FDB entry is notified to all ports currently in bridge
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Michael Chan says:
====================
bnxt_en: PTP enhancements
This series adds two PTP enhancements. This first one is to register
the PHC during probe time and keep it registered whether it is in
ifup or ifdown state. It will get unregistered and possibly
reregistered if the firmware PTP capability changes after firmware
reset. The second one is to add the 1PPS (one pulse per second)
feature to support input/output of the 1PPS signal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
FW can report to driver via ASYNC event if it encountered an
invalid signal on any TSIO PIN. Driver will log this event
for the user to take corrective action.
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Arvind Susarla <arvind.susarla@broadcom.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Once the PPS pins are configured, the FW can report
PPS values using ASYNC event. This patch adds the
ASYNC event handler and subsequent reporting of the
events to kernel.
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Application will send ioctls to set/clear PPS pin functions
based on user input. This patch implements the driver
callbacks that will configure the TSIO pins using firmware
commands. After firmware reset, the TSIO pins will be reconfigured
again.
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1PPS (One Pulse Per Second) is a signal generated either
by the NIC PHC or an external timing source.
Integrating the support to configure and use 1PPS using
the TSIO pins along with PTP timestamps will add Grand
Master capability to the 5750X family chipsets.
This patch initializes the driver data structures and
registers the 1PPS with kernel, based on the TSIO pins'
capability in the hardware. This will create a /dev/ppsX
device which applications can use to receive PPS events.
Later patches will define functions to configure and use
the pins.
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
During error recovery or hot firmware upgrade, the chip may be under
reset and the PHC register read cycles may cause completion timeouts.
Check that the chip is not under reset condition before proceeding
to read the PHC by checking the flag BNXT_STATE_IN_FW_RESET. We also
need to take the ptp_lock before we set this flag to prevent race
conditions.
We need this logic because the PHC now will stay registered after
bnxt_close().
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It was pointed out by Richard Cochran that registering the PHC during
probe is better than during ifup, so move bnxt_ptp_init() back to
bnxt_init_one(). In order to work correctly after firmware reset which
may result in PTP config. changes, we modify bnxt_ptp_init() to return
if the PHC has been registered earlier. If PTP is no longer supported
by the new firmware, we will unregister the PHC and clean up.
This partially reverts:
d7859afb6880 ("bnxt_en: Move bnxt_ptp_init() to bnxt_open()")
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Merge tag 'fixes_for_v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull ext2 and reiserfs fixes from Jan Kara:
"A fix for the ext2 conversion to kmap_local() and two reiserfs
hardening fixes"
* tag 'fixes_for_v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
reiserfs: check directory items on read from disk
fs/ext2: Avoid page_address on pages returned by ext2_get_page
reiserfs: add check for root_inode in reiserfs_fill_super
