linuxmsm/laptops-kernel
0
0
Fork 0
mirror of https://github.com/linux-msm/laptops-kernel.git synced 2026-08-13 14:19:53 -07:00
Code Issues Packages Projects Releases Wiki Activity

bpf,lsm: Drop bpf_prog_free from sleepable_lsm_hooks

Browse Source 
__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: 1b67772e4e ("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
This commit is contained in:
Sechang Lim
2026-07-01 13:10:20 -07:00
committed by Andrii Nakryiko
parent 27a0f3635d
commit 2ce3f548cf
1 changed files with 0 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/bpf/bpf_lsm.c
-1
View File
@@ -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)