From: Thomas Weißschuh linux@weissschuh.net

[ Upstream commit 9c5e490093e83e165022e0311bd7df5aa06cc860 ]

If read() fails and returns -1 (or returns garbage for some other reason) buf would be accessed out of bounds. Only use the return value of read() after it has been validated.

Signed-off-by: Thomas Weißschuh linux@weissschuh.net Signed-off-by: Willy Tarreau w@1wt.eu Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/nolibc/nolibc-test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 55628a25df0a3..8e7750e2eb97c 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -769,7 +769,6 @@ static int expect_vfprintf(int llen, size_t c, const char *expected, const char lseek(fd, 0, SEEK_SET);

r = read(fd, buf, sizeof(buf) - 1); - buf[r] = '\0';

fclose(memfile);

@@ -779,6 +778,7 @@ static int expect_vfprintf(int llen, size_t c, const char *expected, const char return 1; }

+ buf[r] = '\0'; llen += printf(" "%s" = "%s"", expected, buf); ret = strncmp(expected, buf, c);