From 9652c73246b980b9f2387916c35e02638d163472 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 31 Jan 2021 14:40:40 -0500 Subject: [PATCH] 9p: fix misuse of sscanf() in v9fs_stat2inode() 1) sscanf() return value needs to be checked, damnit 2) sscanf() is perfectly capable of checking for fixed prefix, no need for that %13s + strncmp with constant string. 3) st->extension is a valid string; no need for voodoo with str*cpy() there. Signed-off-by: Al Viro --- fs/9p/vfs_inode.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 4a937fac1acb..58f6b56ef145 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -1137,9 +1137,6 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode, struct super_block *sb, unsigned int flags) { umode_t mode; - char ext[32]; - char tag_name[14]; - unsigned int i_nlink; struct v9fs_session_info *v9ses = sb->s_fs_info; struct v9fs_inode *v9inode = V9FS_I(inode); @@ -1157,18 +1154,18 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode, inode->i_gid = stat->n_gid; } if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) { - if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) { + if (v9fs_proto_dotu(v9ses)) { + unsigned int i_nlink; /* - * Hadlink support got added later to - * to the .u extension. So there can be - * server out there that doesn't support - * this even with .u extension. So check - * for non NULL stat->extension + * Hadlink support got added later to the .u extension. + * So there can be a server out there that doesn't + * support this even with .u extension. That would + * just leave us with stat->extension being an empty + * string, though. */ - strlcpy(ext, stat->extension, sizeof(ext)); /* HARDLINKCOUNT %u */ - sscanf(ext, "%13s %u", tag_name, &i_nlink); - if (!strncmp(tag_name, "HARDLINKCOUNT", 13)) + if (sscanf(stat->extension, + " HARDLINKCOUNT %u", &i_nlink) == 1) set_nlink(inode, i_nlink); } }