Newer GCC warns about a possible truncation of a generated sysfs path name as we're concatenating a directory path with a file name and placing the result in a buffer that is half the size of the maximum length of the directory path (which is user controlled).
loopback_test.c: In function 'open_poll_files': loopback_test.c:651:31: warning: '%s' directive output may be truncated writing up to 511 bytes into a region of size 255 [-Wformat-truncation=] 651 | snprintf(buf, sizeof(buf), "%s%s", dev->sysfs_entry, "iteration_count"); | ^~ loopback_test.c:651:3: note: 'snprintf' output between 16 and 527 bytes into a destination of size 255 651 | snprintf(buf, sizeof(buf), "%s%s", dev->sysfs_entry, "iteration_count"); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix this by making sure the buffer is large enough the concatenated strings.
Fixes: 6b0658f68786 ("greybus: tools: Add tools directory to greybus repo and add loopback") Fixes: 9250c0ee2626 ("greybus: Loopback_test: use poll instead of inotify") Signed-off-by: Johan Hovold johan@kernel.org --- drivers/staging/greybus/tools/loopback_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/staging/greybus/tools/loopback_test.c b/drivers/staging/greybus/tools/loopback_test.c index 41e1820d9ac9..d38bb4fbd6b9 100644 --- a/drivers/staging/greybus/tools/loopback_test.c +++ b/drivers/staging/greybus/tools/loopback_test.c @@ -637,7 +637,7 @@ int find_loopback_devices(struct loopback_test *t) static int open_poll_files(struct loopback_test *t) { struct loopback_device *dev; - char buf[MAX_STR_LEN]; + char buf[MAX_SYSFS_PATH + MAX_STR_LEN]; char dummy; int fds_idx = 0; int i;