6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
[ 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>
---
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 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 */
--
2.42.0
