[PATCH 4/4] 9p p9mode2perm: remove useless strlcpy and check sscanf return code

From: Dominique Martinet
Date: Tue Nov 02 2021 - 10:08:42 EST


From: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>

This is also a checkpatch warning fix but this one might have implications
so keeping it separate

Signed-off-by: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>
---
fs/9p/vfs_inode.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 139dfee23b98..328c338ff304 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -109,7 +109,7 @@ static int p9mode2perm(struct v9fs_session_info *v9ses,
static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
struct p9_wstat *stat, dev_t *rdev)
{
- int res;
+ int res, r;
u32 mode = stat->mode;

*rdev = 0;
@@ -127,11 +127,16 @@ static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
res |= S_IFIFO;
else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
&& (v9ses->nodev == 0)) {
- char type = 0, ext[32];
+ char type = 0;
int major = -1, minor = -1;

- strlcpy(ext, stat->extension, sizeof(ext));
- sscanf(ext, "%c %i %i", &type, &major, &minor);
+ r = sscanf(stat->extension, "%c %i %i", &type, &major, &minor);
+ if (r != 3) {
+ p9_debug(P9_DEBUG_ERROR,
+ "invalid device string, umode will be bogus: %s\n",
+ stat->extension);
+ return res;
+ }
switch (type) {
case 'c':
res |= S_IFCHR;
--
2.31.1