| 3f8ad18f | 31-Mar-2025 |
Yonghong Song <[email protected]> |
selftests/bpf: Fix verifier_private_stack test failure
Several verifier_private_stack tests failed with latest bpf-next.
For example, for 'Private stack, single prog' subtest, the
jitted code:
fun
selftests/bpf: Fix verifier_private_stack test failure
Several verifier_private_stack tests failed with latest bpf-next.
For example, for 'Private stack, single prog' subtest, the
jitted code:
func #0:
0: f3 0f 1e fa endbr64
4: 0f 1f 44 00 00 nopl (%rax,%rax)
9: 0f 1f 00 nopl (%rax)
c: 55 pushq %rbp
d: 48 89 e5 movq %rsp, %rbp
10: f3 0f 1e fa endbr64
14: 49 b9 58 74 8a 8f 7d 60 00 00 movabsq $0x607d8f8a7458, %r9
1e: 65 4c 03 0c 25 28 c0 48 87 addq %gs:-0x78b73fd8, %r9
27: bf 2a 00 00 00 movl $0x2a, %edi
2c: 49 89 b9 00 ff ff ff movq %rdi, -0x100(%r9)
33: 31 c0 xorl %eax, %eax
35: c9 leave
36: e9 20 5d 0f e1 jmp 0xffffffffe10f5d5b
The insn 'addq %gs:-0x78b73fd8, %r9' does not match the expected
regex 'addq %gs:0x{{.*}}, %r9' and this caused test failure.
Fix it by changing '%gs:0x{{.*}}' to '%gs:{{.*}}' to accommodate the
possible negative offset. A few other subtests are fixed in a similar way.
Signed-off-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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| 14d84357 | 28-Mar-2025 |
Song Liu <[email protected]> |
selftests/bpf: Fix verifier_bpf_fastcall test
Commit [1] moves percpu data on x86 from address 0x000... to address
0xfff...
Before [1]:
159020: 0000000000030700 0 OBJECT GLOBAL DEFAULT 23 p
selftests/bpf: Fix verifier_bpf_fastcall test
Commit [1] moves percpu data on x86 from address 0x000... to address
0xfff...
Before [1]:
159020: 0000000000030700 0 OBJECT GLOBAL DEFAULT 23 pcpu_hot
After [1]:
152602: ffffffff83a3e034 4 OBJECT GLOBAL DEFAULT 35 pcpu_hot
As a result, verifier_bpf_fastcall tests should now expect a negative
value for pcpu_hot, IOW, the disassemble should show "r=" instead of
"w=".
Fix this in the test.
Note that, a later change created a new variable "cpu_number" for
bpf_get_smp_processor_id() [2]. The inlining logic is updated properly
as part of this change, so there is no need to fix anything on the
kernel side.
[1] commit 9d7de2aa8b41 ("x86/percpu/64: Use relative percpu offsets")
[2] commit 01c7bc5198e9 ("x86/smp: Move cpu number to percpu hot section")
Reported-by: Jakub Kicinski <[email protected]>
Signed-off-by: Song Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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| 5f3077d7 | 22-Mar-2025 |
Kohei Enju <[email protected]> |
selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid
syzbot reported out-of-bounds read in check_atomic_load/store() when the
register number is invalid in thi
selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid
syzbot reported out-of-bounds read in check_atomic_load/store() when the
register number is invalid in this context:
https://syzkaller.appspot.com/bug?extid=a5964227adc0f904549c
To avoid the issue from now on, let's add tests where the register number
is invalid for load-acquire/store-release.
After discussion with Eduard, I decided to use R15 as invalid register
because the actual slab-out-of-bounds read issue occurs when the register
number is R12 or larger.
Signed-off-by: Kohei Enju <[email protected]>
Acked-by: Eduard Zingerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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| c03bb2fa | 22-Mar-2025 |
Kohei Enju <[email protected]> |
bpf: Fix out-of-bounds read in check_atomic_load/store()
syzbot reported the following splat [0].
In check_atomic_load/store(), register validity is not checked before
atomic_ptr_type_ok(). This ca
bpf: Fix out-of-bounds read in check_atomic_load/store()
syzbot reported the following splat [0].
In check_atomic_load/store(), register validity is not checked before
atomic_ptr_type_ok(). This causes the out-of-bounds read in is_ctx_reg()
called from atomic_ptr_type_ok() when the register number is MAX_BPF_REG
or greater.
Call check_load_mem()/check_store_reg() before atomic_ptr_type_ok()
to avoid the OOB read.
However, some tests introduced by commit ff3afe5da998 ("selftests/bpf: Add
selftests for load-acquire and store-release instructions") assume
calling atomic_ptr_type_ok() before checking register validity.
Therefore the swapping of order unintentionally changes verifier messages
of these tests.
For example in the test load_acquire_from_pkt_pointer(), expected message
is 'BPF_ATOMIC loads from R2 pkt is not allowed' although actual messages
are different.
validate_msgs:FAIL:754 expect_msg
VERIFIER LOG:
=============
Global function load_acquire_from_pkt_pointer() doesn't return scalar. Only those are supported.
0: R1=ctx() R10=fp0
; asm volatile ( @ verifier_load_acquire.c:140
0: (61) r2 = *(u32 *)(r1 +0) ; R1=ctx() R2_w=pkt(r=0)
1: (d3) r0 = load_acquire((u8 *)(r2 +0))
invalid access to packet, off=0 size=1, R2(id=0,off=0,r=0)
R2 offset is outside of the packet
processed 2 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
=============
EXPECTED SUBSTR: 'BPF_ATOMIC loads from R2 pkt is not allowed'
#505/19 verifier_load_acquire/load-acquire from pkt pointer:FAIL
This is because instructions in the test don't pass check_load_mem() and
therefore don't enter the atomic_ptr_type_ok() path.
In this case, we have to modify instructions so that they pass the
check_load_mem() and trigger atomic_ptr_type_ok().
Similarly for store-release tests, we need to modify instructions so that
they pass check_store_reg().
Like load_acquire_from_pkt_pointer(), modify instructions in:
load_acquire_from_sock_pointer()
store_release_to_ctx_pointer()
store_release_to_pkt_pointer()
Also in store_release_to_sock_pointer(), check_store_reg() returns error
early and atomic_ptr_type_ok() is not triggered, since write to sock
pointer is not possible in general.
We might be able to remove the test, but for now let's leave it and just
change the expected message.
[0]
BUG: KASAN: slab-out-of-bounds in is_ctx_reg kernel/bpf/verifier.c:6185 [inline]
BUG: KASAN: slab-out-of-bounds in atomic_ptr_type_ok+0x3d7/0x550 kernel/bpf/verifier.c:6223
Read of size 4 at addr ffff888141b0d690 by task syz-executor143/5842
CPU: 1 UID: 0 PID: 5842 Comm: syz-executor143 Not tainted 6.14.0-rc3-syzkaller-gf28214603dc6 #0
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0x16e/0x5b0 mm/kasan/report.c:521
kasan_report+0x143/0x180 mm/kasan/report.c:634
is_ctx_reg kernel/bpf/verifier.c:6185 [inline]
atomic_ptr_type_ok+0x3d7/0x550 kernel/bpf/verifier.c:6223
check_atomic_store kernel/bpf/verifier.c:7804 [inline]
check_atomic kernel/bpf/verifier.c:7841 [inline]
do_check+0x89dd/0xedd0 kernel/bpf/verifier.c:19334
do_check_common+0x1678/0x2080 kernel/bpf/verifier.c:22600
do_check_main kernel/bpf/verifier.c:22691 [inline]
bpf_check+0x165c8/0x1cca0 kernel/bpf/verifier.c:23821
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=a5964227adc0f904549c
Tested-by: [email protected]
Fixes: e24bbad29a8d ("bpf: Introduce load-acquire and store-release instructions")
Fixes: ff3afe5da998 ("selftests/bpf: Add selftests for load-acquire and store-release instructions")
Signed-off-by: Kohei Enju <[email protected]>
Acked-by: Eduard Zingerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
show more ...
|
| e16e64f9 | 18-Mar-2025 |
Björn Töpel <[email protected]> |
selftests/bpf: Sanitize pointer prior fclose()
There are scenarios where env.{sub,}test_state->stdout_saved, can be
NULL, e.g. sometimes when the watchdog timeout kicks in, or if the
open_memstream
selftests/bpf: Sanitize pointer prior fclose()
There are scenarios where env.{sub,}test_state->stdout_saved, can be
NULL, e.g. sometimes when the watchdog timeout kicks in, or if the
open_memstream syscall is not available.
Avoid crashing test_progs by adding an explicit NULL check prior the
fclose() call.
Signed-off-by: Björn Töpel <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
show more ...
|
| 8c10109a | 11-Mar-2025 |
Saket Kumar Bhaskar <[email protected]> |
selftests/bpf: Fix sockopt selftest failure on powerpc
The SO_RCVLOWAT option is defined as 18 in the selftest header,
which matches the generic definition. However, on powerpc,
SO_RCVLOWAT is defin
selftests/bpf: Fix sockopt selftest failure on powerpc
The SO_RCVLOWAT option is defined as 18 in the selftest header,
which matches the generic definition. However, on powerpc,
SO_RCVLOWAT is defined as 16. This discrepancy causes
sol_socket_sockopt() to fail with the default switch case on powerpc.
This commit fixes by defining SO_RCVLOWAT as 16 for powerpc.
Signed-off-by: Saket Kumar Bhaskar <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Tested-by: Venkat Rao Bagalkote <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
show more ...
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| de07b182 | 13-Mar-2025 |
Viktor Malik <[email protected]> |
selftests/bpf: Fix string read in strncmp benchmark
The strncmp benchmark uses the bpf_strncmp helper and a hand-written
loop to compare two strings. The values of the strings are filled from
usersp
selftests/bpf: Fix string read in strncmp benchmark
The strncmp benchmark uses the bpf_strncmp helper and a hand-written
loop to compare two strings. The values of the strings are filled from
userspace. One of the strings is non-const (in .bss) while the other is
const (in .rodata) since that is the requirement of bpf_strncmp.
The problem is that in the hand-written loop, Clang optimizes the reads
from the const string to always return 0 which breaks the benchmark.
Use barrier_var to prevent the optimization.
The effect can be seen on the strncmp-no-helper variant.
Before this change:
# ./bench strncmp-no-helper
Setting up benchmark 'strncmp-no-helper'...
Benchmark 'strncmp-no-helper' started.
Iter 0 (112.309us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 1 (-23.238us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 2 ( 58.994us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 3 (-30.466us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 4 ( 29.996us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 5 ( 16.949us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Iter 6 (-60.035us): hits 0.000M/s ( 0.000M/prod), drops 0.000M/s, total operations 0.000M/s
Summary: hits 0.000 ± 0.000M/s ( 0.000M/prod), drops 0.000 ± 0.000M/s, total operations 0.000 ± 0.000M/s
After this change:
# ./bench strncmp-no-helper
Setting up benchmark 'strncmp-no-helper'...
Benchmark 'strncmp-no-helper' started.
Iter 0 ( 77.711us): hits 5.534M/s ( 5.534M/prod), drops 0.000M/s, total operations 5.534M/s
Iter 1 ( 11.215us): hits 6.006M/s ( 6.006M/prod), drops 0.000M/s, total operations 6.006M/s
Iter 2 (-14.253us): hits 5.931M/s ( 5.931M/prod), drops 0.000M/s, total operations 5.931M/s
Iter 3 ( 59.087us): hits 6.005M/s ( 6.005M/prod), drops 0.000M/s, total operations 6.005M/s
Iter 4 (-21.379us): hits 6.010M/s ( 6.010M/prod), drops 0.000M/s, total operations 6.010M/s
Iter 5 (-20.310us): hits 5.861M/s ( 5.861M/prod), drops 0.000M/s, total operations 5.861M/s
Iter 6 ( 53.937us): hits 6.004M/s ( 6.004M/prod), drops 0.000M/s, total operations 6.004M/s
Summary: hits 5.969 ± 0.061M/s ( 5.969M/prod), drops 0.000 ± 0.000M/s, total operations 5.969 ± 0.061M/s
Fixes: 9c42652f8be3 ("selftests/bpf: Add benchmark for bpf_strncmp() helper")
Suggested-by: Andrii Nakryiko <[email protected]>
Signed-off-by: Viktor Malik <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Hou Tao <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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| 1f375aef | 11-Mar-2025 |
Kumar Kartikeya Dwivedi <[email protected]> |
selftests/bpf: Fix arena_spin_lock compilation on PowerPC
Venkat reported a compilation error for BPF selftests on PowerPC [0].
The crux of the error is the following message:
In file included fro
selftests/bpf: Fix arena_spin_lock compilation on PowerPC
Venkat reported a compilation error for BPF selftests on PowerPC [0].
The crux of the error is the following message:
In file included from progs/arena_spin_lock.c:7:
/root/bpf-next/tools/testing/selftests/bpf/bpf_arena_spin_lock.h:122:8:
error: member reference base type '__attribute__((address_space(1)))
u32' (aka '__attribute__((address_space(1))) unsigned int') is not a
structure or union
122 | old = atomic_read(&lock->val);
This is because PowerPC overrides the qspinlock type changing the
lock->val member's type from atomic_t to u32.
To remedy this, import the asm-generic version in the arena spin lock
header, name it __qspinlock (since it's aliased to arena_spinlock_t, the
actual name hardly matters), and adjust the selftest to not depend on
the type in vmlinux.h.
[0]: https://lore.kernel.org/bpf/[email protected]
Fixes: 88d706ba7cc5 ("selftests/bpf: Introduce arena spin lock")
Reported-by: Venkat Rao Bagalkote <[email protected]>
Signed-off-by: Kumar Kartikeya Dwivedi <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Tested-by: Venkat Rao Bagalkote <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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| 082f1db0 | 10-Mar-2025 |
Blaise Boscaccy <[email protected]> |
security: Propagate caller information in bpf hooks
Certain bpf syscall subcommands are available for usage from both
userspace and the kernel. LSM modules or eBPF gatekeeper programs may
need to ta
security: Propagate caller information in bpf hooks
Certain bpf syscall subcommands are available for usage from both
userspace and the kernel. LSM modules or eBPF gatekeeper programs may
need to take a different course of action depending on whether or not
a BPF syscall originated from the kernel or userspace.
Additionally, some of the bpf_attr struct fields contain pointers to
arbitrary memory. Currently the functionality to determine whether or
not a pointer refers to kernel memory or userspace memory is exposed
to the bpf verifier, but that information is missing from various LSM
hooks.
Here we augment the LSM hooks to provide this data, by simply passing
a boolean flag indicating whether or not the call originated in the
kernel, in any hook that contains a bpf_attr struct that corresponds
to a subcommand that may be called from the kernel.
Signed-off-by: Blaise Boscaccy <[email protected]>
Acked-by: Song Liu <[email protected]>
Acked-by: Paul Moore <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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| a03d3753 | 10-Mar-2025 |
Chen Ni <[email protected]> |
selftests/bpf: Convert comma to semicolon
Replace comma between expressions with semicolons.
Using a ',' in place of a ';' can have unintended side effects.
Although that is not the case here, it i
selftests/bpf: Convert comma to semicolon
Replace comma between expressions with semicolons.
Using a ',' in place of a ';' can have unintended side effects.
Although that is not the case here, it is seems best to use ';'
unless ',' is intended.
Found by inspection.
No functional change intended.
Compile tested only.
Signed-off-by: Chen Ni <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Anton Protopopov <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
show more ...
|