| Message ID | 20231016062446.695-1-binbin.wu@linux.intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] selftests/x86/lam: Zero out buffer for readlink() | expand |
On Mon, Oct 16, 2023 at 02:24:46PM +0800, Binbin Wu wrote: > 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> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
On 10/16/23 02:47, kirill.shutemov@linux.intel.com wrote: > On Mon, Oct 16, 2023 at 02:24:46PM +0800, Binbin Wu wrote: >> 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> > > Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Thank you. Applied to linux-kselftest next for Linux 6.7-rc1 thanks, -- Shuah
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 */
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(-) base-commit: 58720809f52779dc0f08e53e54b014209d13eebb