bpf: Check active lock count in in_sleepable_context()

The in_sleepable_context() function is used to specialize the BPF code
in do_misc_fixups(). With the addition of nonsleepable arena kfuncs,
there are kfuncs whose specialization depends on whether we are
holding a lock. We should use the nonsleepable version while
holding a lock and the sleepable one when not.

Add a check for active_locks to account for locking when specializing
arena kfuncs.

Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260106-arena-under-lock-v2-1-378e9eab3066@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 9394b0de2ef0085690b0a0052f82cd48d8722e89..7f82e27dd7e7c3e8328a5c4aa629b79db2dbe03f 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -11466,6 +11466,7 @@ static inline bool in_sleepable_context(struct bpf_verifier_env *env)
 {
        return !env->cur_state->active_rcu_locks &&
               !env->cur_state->active_preempt_locks &&
+              !env->cur_state->active_locks &&
               !env->cur_state->active_irq_id &&
               in_sleepable(env);
 }