leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup()

Browse Source 
Add checking for the path component length and verify it is <= the maximum
that the server advertizes via FileFsAttributeInformation.

With this patch cifs.ko will now return ENAMETOOLONG instead of ENOENT
when users to access an overlong path.

To test this, try to cd into a (non-existing) directory on a CIFS share
that has a too long name:
cd /mnt/aaaaaaaaaaaaaaa...

and it now should show a good error message from the shell:
bash: cd: /mnt/aaaaaaaaaaaaaaaa...aaaaaa: File name too long

rh bz 1153996

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Cc: <stable@vger.kernel.org>
This commit is contained in:
Ronnie Sahlberg 2017-08-23 14:48:14 +10:00 committed by Steve French
parent 42bec214d8
commit d3edede29f
1 changed files with 12 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
fs/cifs/dir.c
View File

@ -194,15 +194,20 @@ cifs_bp_rename_retry:
}
/*
* Don't allow path components longer than the server max.
* Don't allow the separator character in a path component.
* The VFS will not allow "/", but "\" is allowed by posix.
*/
static int
check_name(struct dentry *direntry)
check_name(struct dentry *direntry, struct cifs_tcon *tcon)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
int i;
if (unlikely(direntry->d_name.len >
tcon->fsAttrInfo.MaxPathNameComponentLength))
return -ENAMETOOLONG;
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
for (i = 0; i < direntry->d_name.len; i++) {
if (direntry->d_name.name[i] == '\\') {
@ -500,10 +505,6 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry,
return finish_no_open(file, res);
}
rc = check_name(direntry);
if (rc)
return rc;
xid = get_xid();
cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
@ -516,6 +517,11 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry,
}
tcon = tlink_tcon(tlink);
rc = check_name(direntry, tcon);
if (rc)
goto out_free_xid;
server = tcon->ses->server;
if (server->ops->new_lease_key)
@ -776,7 +782,7 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
}
pTcon = tlink_tcon(tlink);
rc = check_name(direntry);
rc = check_name(direntry, pTcon);
if (rc)
goto lookup_out;