print_reg_state() should not consider adding reg->off to reg->var_off.value
when dumping scalars. Scalars can be produced with reg->off != 0 through
BPF_ADD_CONST, and thus as-is this can skew the register log dump.
Fixes: 98d7ca374ba4 ("bpf: Track delta between "linked" registers.")
Reported-by: Nathaniel Theis <nathaniel.theis@xxxxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
---
kernel/bpf/log.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c
index 5aebfc3051e3..4a858fdb6476 100644
--- a/kernel/bpf/log.c
+++ b/kernel/bpf/log.c
@@ -688,8 +688,7 @@ static void print_reg_state(struct bpf_verifier_env *env,
if (t == SCALAR_VALUE && reg->precise)
verbose(env, "P");
if (t == SCALAR_VALUE && tnum_is_const(reg->var_off)) {
- /* reg->off should be 0 for SCALAR_VALUE */
- verbose_snum(env, reg->var_off.value + reg->off);
+ verbose_snum(env, reg->var_off.value);
return;
}
--
2.43.0
