Messages in this thread | | | Date | Tue, 10 Oct 2023 11:51:32 +0800 | Subject | Re: [PATCH] selftests/x86/lam: Zero out buffer for readlink() | From | Binbin Wu <> |
| |
On 9/27/2023 7:02 PM, kirill.shutemov@linux.intel.com wrote: > On Sun, Sep 24, 2023 at 07:33:46AM +0800, Binbin Wu wrote: >> Zero out the buffer for readlink() since readlink() does not append a >> terminating null byte to the buffer. >> >> Fixes: 833c12ce0f430 ("selftests/x86/lam: Add inherit test cases for linear-address masking") >> >> Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com> >> --- >> tools/testing/selftests/x86/lam.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/testing/selftests/x86/lam.c b/tools/testing/selftests/x86/lam.c >> index eb0e46905bf9..9f06942a8e25 100644 >> --- a/tools/testing/selftests/x86/lam.c >> +++ b/tools/testing/selftests/x86/lam.c >> @@ -680,7 +680,7 @@ 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}; > Shouldn't it be PATH_MAX+1 to handle the case when readlink(2) stores > exactly PATH_MAX bytes into the buffer? According to the definition of PATH_MAX in include/uapi/linux/limits.h #define PATH_MAX 4096 /* # chars in a path name including nul */
IIUC, Linux limits the path length to 4095 and PATH_MAX includes the terminating nul.
> >> >> /* Set LAM mode in parent process */ >> if (set_lam(lam) != 0) >> >> base-commit: ce9ecca0238b140b88f43859b211c9fdfd8e5b70 >> -- >> 2.25.1 >>
| |