selftests/x86/lam: Zero out buffer for readlink()

[ Upstream commit 29060633411a02f6f2dd9d5245919385d69d81f0 ]

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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/20231016062446.695-1-binbin.wu@linux.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Binbin Wu 2023-10-16 14:24:46 +08:00 committed by Greg Kroah-Hartman
parent b0ebeb5956
commit b13513e764

View File

@ -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 */