An iterator stack slot can be MEM_RCU or PTR_UNTRUSTED. These states
must not be equal, or the verifier can prune an unsafe path.
Compare the pointer type for STACK_ITER slots.
Fixes: dfab99df147b ("bpf: teach the verifier to enforce css_iter and task_iter
in RCU CS")
Signed-off-by: Ning Ding <[email protected]>
Acked-by: Eduard Zingerman <[email protected]>
---
kernel/bpf/states.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/states.c b/kernel/bpf/states.c
index ea2153cf28d0a..4e6aafad33bd2 100644
--- a/kernel/bpf/states.c
+++ b/kernel/bpf/states.c
@@ -812,7 +812,8 @@ static bool stacksafe(struct bpf_verifier_env *env, struct
bpf_func_state *old,
* infinite loop check triggering, see
* iter_active_depths_differ()
*/
- if (old_reg->iter.btf != cur_reg->iter.btf ||
+ if (old_reg->type != cur_reg->type ||
+ old_reg->iter.btf != cur_reg->iter.btf ||
old_reg->iter.btf_id != cur_reg->iter.btf_id ||
old_reg->iter.state != cur_reg->iter.state ||
/* ignore {old_reg,cur_reg}->iter.depth, see above
*/
--
2.43.0
