[PATCH AUTOSEL 5.15 10/20] pstore/zone: Add a null pointer check to the psz_kmsg_read

[Sasha Levin]

From: Kunwu Chan <chentao@xxxxxxxxxx>

[ Upstream commit 98bc7e26e14fbb26a6abf97603d59532475e97f8 ]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.

Signed-off-by: Kunwu Chan <chentao@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240118100206.213928-1-chentao@xxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/pstore/zone.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c
index 5d3f944f60185..295040c249d91 100644
--- a/fs/pstore/zone.c
+++ b/fs/pstore/zone.c
@@ -973,6 +973,8 @@ static ssize_t psz_kmsg_read(struct pstore_zone *zone,
 		char *buf = kasprintf(GFP_KERNEL, "%s: Total %d times\n",
 				      kmsg_dump_reason_str(record->reason),
 				      record->count);
+		if (!buf)
+			return -ENOMEM;
 		hlen = strlen(buf);
 		record->buf = krealloc(buf, hlen + size, GFP_KERNEL);
 		if (!record->buf) {
-- 
2.43.0