read_iter() always NUL-terminated at the end of the buffer, so strstr() could scan uninitialized stack bytes on short reads. Terminate at len and use O_RDONLY.
Signed-off-by: Sun Jian <[email protected]> --- tools/testing/selftests/bpf/prog_tests/test_bpffs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c index ea933fd151c3..e8021ff0581c 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c +++ b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c @@ -17,11 +17,11 @@ static int read_iter(char *file) char buf[1024]; int fd, len; - fd = open(file, 0); + fd = open(file, O_RDONLY); if (fd < 0) return -1; - while ((len = read(fd, buf, sizeof(buf))) > 0) { - buf[sizeof(buf) - 1] = '\0'; + while ((len = read(fd, buf, sizeof(buf) - 1)) > 0) { + buf[len] = '\0'; if (strstr(buf, "iter")) { close(fd); return 0; base-commit: 1f318b96cc84d7c2ab792fcc0bfd42a7ca890681 -- 2.43.0
