This is a note to let you know that I've just added the patch titled
selftests/x86/lam: Zero out buffer for readlink()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-x86-lam-zero-out-buffer-for-readlink.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 546103aba344fd0ab05c2b336b1dd71e711ffd31
Author: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
Date: Mon Oct 16 14:24:46 2023 +0800
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@xxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231016062446.695-1-binbin.wu@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/testing/selftests/x86/lam.c b/tools/testing/selftests/x86/lam.c
index eb0e46905bf9d..8f9b06d9ce039 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 */
