On 4/9/24 5:33 PM, Edward Adam Davis wrote:
The strnchr() is not suitable for obtaining the end of a string with a length
exceeding 1 and ending with a NUL character.
Could you give more detailed explanation with specific examples? I think
strnchr() does the right thing here. Note that if fmt is not NULL,
strnchrnul() never returns NULL pointer so in the change below,
'if (!fmt_end)' will be always false.
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;
