diff options
| author | Ihor Solodrai <ihor.solodrai@linux.dev> | 2026-03-19 17:08:09 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-03-21 12:51:44 -0700 |
| commit | a1e5c46eaed3151be93e1aec9af0d8f8db79b8f6 (patch) | |
| tree | 772297acd3f36ad1bb6afb699b838187b0f3ee32 /tools | |
| parent | 6c2128505f61b504c79a20b89596feba61388112 (diff) | |
selftests/bpf: Add tests for bpf_throw lock leak from subprogs
Add test cases to ensure the verifier correctly rejects bpf_throw from
subprogs when RCU, preempt, or IRQ locks are held:
* reject_subprog_rcu_lock_throw: subprog acquires bpf_rcu_read_lock and
then calls bpf_throw
* reject_subprog_throw_preempt_lock: always-throwing subprog called while
caller holds bpf_preempt_disable
* reject_subprog_throw_irq_lock: always-throwing subprog called while
caller holds bpf_local_irq_save
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260320000809.643798-2-ihor.solodrai@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/exceptions_fail.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/exceptions_fail.c b/tools/testing/selftests/bpf/progs/exceptions_fail.c index d7f1c492e3dd..9ea1353488d7 100644 --- a/tools/testing/selftests/bpf/progs/exceptions_fail.c +++ b/tools/testing/selftests/bpf/progs/exceptions_fail.c @@ -9,6 +9,10 @@ extern void bpf_rcu_read_lock(void) __ksym; extern void bpf_rcu_read_unlock(void) __ksym; +extern void bpf_preempt_disable(void) __ksym; +extern void bpf_preempt_enable(void) __ksym; +extern void bpf_local_irq_save(unsigned long *) __ksym; +extern void bpf_local_irq_restore(unsigned long *) __ksym; #define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8))) @@ -349,4 +353,47 @@ int reject_exception_throw_cb_diff(struct __sk_buff *ctx) return 0; } +__noinline static int always_throws(void) +{ + bpf_throw(0); + return 0; +} + +__noinline static int rcu_lock_then_throw(void) +{ + bpf_rcu_read_lock(); + bpf_throw(0); + return 0; +} + +SEC("?tc") +__failure __msg("bpf_throw cannot be used inside bpf_rcu_read_lock-ed region") +int reject_subprog_rcu_lock_throw(void *ctx) +{ + rcu_lock_then_throw(); + return 0; +} + +SEC("?tc") +__failure __msg("bpf_throw cannot be used inside bpf_preempt_disable-ed region") +int reject_subprog_throw_preempt_lock(void *ctx) +{ + bpf_preempt_disable(); + always_throws(); + bpf_preempt_enable(); + return 0; +} + +SEC("?tc") +__failure __msg("bpf_throw cannot be used inside bpf_local_irq_save-ed region") +int reject_subprog_throw_irq_lock(void *ctx) +{ + unsigned long flags; + + bpf_local_irq_save(&flags); + always_throws(); + bpf_local_irq_restore(&flags); + return 0; +} + char _license[] SEC("license") = "GPL"; |