From 2ce3f548cfc6a1fe4c53479cf8a21931cdfd51d8 Mon Sep 17 00:00:00 2001 From: Sechang Lim Date: Wed, 1 Jul 2026 08:07:51 +0000 Subject: [PATCH] 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: __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 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 Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260701080757.1394144-1-rhkrqnwk98@gmail.com --- kernel/bpf/bpf_lsm.c | 1 - 1 file changed, 1 deletion(-) 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)