diff options
| author | Mykyta Yatsenko <yatsenko@meta.com> | 2025-09-23 12:23:59 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-09-23 07:34:38 -0700 |
| commit | d2699bdb6ebad4fecd0f8765f35bd32a4a142b16 (patch) | |
| tree | 327c0cc222dbe80beea084d378bdebabc762e76a /kernel | |
| parent | acc3a0d2506c1b8186e9190adcd5bee4a1932abc (diff) | |
bpf: verifier: permit non-zero returns from async callbacks
The verifier currently enforces a zero return value for all async
callbacks—a constraint originally introduced for bpf_timer. That
restriction is too narrow for other async use cases.
Relax the rule by allowing non-zero return codes from async callbacks in
general, while preserving the zero-return requirement for bpf_timer to
maintain its existing semantics.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250923112404.668720-5-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index c1b726fb22c8..02b93a54a446 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -10789,7 +10789,7 @@ static int set_timer_callback_state(struct bpf_verifier_env *env, __mark_reg_not_init(env, &callee->regs[BPF_REG_4]); __mark_reg_not_init(env, &callee->regs[BPF_REG_5]); callee->in_async_callback_fn = true; - callee->callback_ret_range = retval_range(0, 1); + callee->callback_ret_range = retval_range(0, 0); return 0; } @@ -17073,9 +17073,8 @@ static int check_return_code(struct bpf_verifier_env *env, int regno, const char } if (frame->in_async_callback_fn) { - /* enforce return zero from async callbacks like timer */ exit_ctx = "At async callback return"; - range = retval_range(0, 0); + range = frame->callback_ret_range; goto enforce_retval; } |