Zero out the buffer for readlink() since readlink() does not append a terminating null byte to the buffer. Also change the buffer length passed to readlink() to 'PATH_MAX - 1' to ensure the resulting string is always null terminated.

Fixes: 833c12ce0f430 ("selftests/x86/lam: Add inherit test cases for linear-address masking")

Signed-off-by: Binbin Wu binbin.wu@linux.intel.com --- v1->v2: - Change the buffer length passed to readlink() to 'PATH_MAX - 1' to ensure the resulting string is always null terminated. [Kirill]

tools/testing/selftests/x86/lam.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/x86/lam.c b/tools/testing/selftests/x86/lam.c index eb0e46905bf9..8f9b06d9ce03 100644 --- a/tools/testing/selftests/x86/lam.c +++ b/tools/testing/selftests/x86/lam.c @@ -573,7 +573,7 @@ int do_uring(unsigned long lam) char path[PATH_MAX] = {0};

/* get current process path */ - if (readlink("/proc/self/exe", path, PATH_MAX) <= 0) + if (readlink("/proc/self/exe", path, PATH_MAX - 1) <= 0) return 1;

int file_fd = open(path, O_RDONLY); @@ -680,14 +680,14 @@ static int handle_execve(struct testcases *test) perror("Fork failed."); ret = 1; } else if (pid == 0) { - char path[PATH_MAX]; + char path[PATH_MAX] = {0};

/* Set LAM mode in parent process */ if (set_lam(lam) != 0) return 1;

/* Get current binary's path and the binary was run by execve */ - if (readlink("/proc/self/exe", path, PATH_MAX) <= 0) + if (readlink("/proc/self/exe", path, PATH_MAX - 1) <= 0) exit(-1);

/* run binary to get LAM mode and return to parent process */

base-commit: 58720809f52779dc0f08e53e54b014209d13eebb