[PATCH] bpf: strnchr not suitable for getting NUL-terminator

From: Edward Adam Davis
Date: Tue Apr 09 2024 - 20:33:22 EST


The strnchr() is not suitable for obtaining the end of a string with a length
exceeding 1 and ending with a NUL character.

Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>
---
kernel/bpf/helpers.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 449b9a5d3fe3..07490eba24fe 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -826,7 +826,7 @@ int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args,
u64 cur_arg;
char fmt_ptype, cur_ip[16], ip_spec[] = "%pXX";

- fmt_end = strnchr(fmt, fmt_size, 0);
+ fmt_end = strnchrnul(fmt, fmt_size, 0);
if (!fmt_end)
return -EINVAL;
fmt_size = fmt_end - fmt;
--
2.43.0