On Tue, 30 Oct 2012 16:43:33 +0000 Sachin Prabhu <sprabhu@xxxxxxxxxx> wrote: > 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@xxxxxxxxxx> # 3.6.x > Reported-by: Vit Zahradka <vit.zahradka@xxxxxxxxxx> > Signed-off-by: Sachin Prabhu <sprabhu@xxxxxxxxxx> > --- > fs/cifs/dir.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c > index 7c0a812..e26d0a6 100644 > --- a/fs/cifs/dir.c > +++ b/fs/cifs/dir.c > @@ -398,6 +398,12 @@ 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); Acked-by: Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
