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| author | Sechang Lim <rhkrqnwk98@gmail.com> | 2026-07-01 08:07:51 +0000 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2026-07-01 13:10:20 -0700 |
| commit | 2ce3f548cfc6a1fe4c53479cf8a21931cdfd51d8 (patch) | |
| tree | 48169be3ebfa0bf538536c469c84f8677f9f0961 | |
| parent | 27a0f3635d862919dd7e5e93e19f3f5d1b240e57 (diff) | |
| download | linux-next-2ce3f548cfc6a1fe4c53479cf8a21931cdfd51d8.tar.gz linux-next-2ce3f548cfc6a1fe4c53479cf8a21931cdfd51d8.zip | |
bpf,lsm: Drop bpf_prog_free from sleepable_lsm_hooks
__bpf_prog_put_rcu() is the call_rcu() callback for non-sleepable programs.
security_bpf_prog_free() called from there fires bpf_prog_free in softirq;
if a sleepable LSM prog is attached to that hook, might_fault() BUGs:
BUG: sleeping function called from invalid context
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 5038
preempt_count: 101, expected: 0
Call Trace:
<IRQ>
__bpf_prog_enter_sleepable+0x1cd/0x320 kernel/bpf/trampoline.c:1255
bpf_trampoline_6442549705+0x53/0xd7
security_bpf_prog_free+0xde/0x130 security/security.c:5465
__bpf_prog_put_rcu+0xab/0xd0 kernel/bpf/syscall.c:2365
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
handle_softirqs+0x236/0x800 kernel/softirq.c:622
</IRQ>
The call_rcu/call_rcu_tasks_trace split reflects the freed program's
sleepability, not that of any attached observer.
security_bpf_prog_free() also frees prog->aux->security, which has to stay
after the grace period, so drop bpf_prog_free from sleepable_lsm_hooks
rather than move the call. Non-sleepable observers still run there.
Fixes: 1b67772e4e3f ("bpf,lsm: Refactor bpf_prog_alloc/bpf_prog_free LSM hooks")
Signed-off-by: Sechang Lim <rhkrqnwk98@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260701080757.1394144-1-rhkrqnwk98@gmail.com
| -rw-r--r-- | kernel/bpf/bpf_lsm.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c index 1433809bb166..3983b4ce73c8 100644 --- a/kernel/bpf/bpf_lsm.c +++ b/kernel/bpf/bpf_lsm.c @@ -295,7 +295,6 @@ BTF_ID(func, bpf_lsm_bpf_map_create) BTF_ID(func, bpf_lsm_bpf_map_free) BTF_ID(func, bpf_lsm_bpf_prog) BTF_ID(func, bpf_lsm_bpf_prog_load) -BTF_ID(func, bpf_lsm_bpf_prog_free) BTF_ID(func, bpf_lsm_bpf_token_create) BTF_ID(func, bpf_lsm_bpf_token_free) BTF_ID(func, bpf_lsm_bpf_token_cmd) |