| Message ID | 1351624868-14936-1-git-send-email-sprabhu@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 7c0a812..d903647 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -398,6 +398,13 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry, * in network traffic in the other paths. */ if (!(oflags & O_CREAT)) { + /* + * Check for hashed negative dentry. We have already revalidated + * the dentry and it is fine. No need to perform another lookup. + */ + if (!d_unhashed(direntry)) + return -ENOENT; + struct dentry *res = cifs_lookup(inode, direntry, 0); if (IS_ERR(res)) return PTR_ERR(res);
We do not need to lookup a hashed negative directory since we have already revalidated it before and have found it to be fine. This also prevents a crash in cifs_lookup() when it attempts to rehash the already hashed negative lookup dentry. The patch has been tested using the reproducer at https://bugzilla.redhat.com/show_bug.cgi?id=867344#c28 Cc: <stable@kernel.org> # 3.6.x Reported-by: Vit Zahradka <vit.zahradka@tiscali.cz> Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> --- fs/cifs/dir.c | 7 +++++++ 1 file changed, 7 insertions(+)