[PATCH bpf-next v9 02/23] bpf/verifier: do not clear meta in check_mem_size

From: Benjamin Tissoires
Date: Wed Aug 24 2022 - 09:41:36 EST


The purpose of this clear is to prevent meta->raw_mode to be evaluated
at true, but this also prevents to forward any other data to the other
callees.

Only switch back raw_mode to false so we don't entirely clear meta.

Acked-by: Yonghong Song <yhs@xxxxxx>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

---

no changes in v9

no changes in v8

no changes in v7

new in v6
---
kernel/bpf/verifier.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d694f43ab911..13190487fb12 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5287,7 +5287,7 @@ static int check_mem_size_reg(struct bpf_verifier_env *env,
* initialize all the memory that the helper could
* just partially fill up.
*/
- meta = NULL;
+ meta->raw_mode = false;

if (reg->smin_value < 0) {
verbose(env, "R%d min value is negative, either use unsigned or 'var &= const'\n",
--
2.36.1