From 884ea892763d4dfba509743f65961c782c0442db Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Mon, 22 Nov 2010 22:58:06 -0800 Subject: [PATCH] ceph: avoid possible null deref in readdir after dir llseek last may be NULL, but we dereference it in the else branch without checking. Normally it doesn't trigger because last == NULL when fpos == 2, but it could happen on a newly opened dir if the user seeks forward. Reported-by: Dan Carpenter Signed-off-by: Sage Weil --- fs/ceph/dir.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 7d447af..158c700 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -114,8 +114,8 @@ static int __dcache_readdir(struct file *filp, spin_lock(&dcache_lock); /* start at beginning? */ - if (filp->f_pos == 2 || (last && - filp->f_pos < ceph_dentry(last)->offset)) { + if (filp->f_pos == 2 || last == NULL || + filp->f_pos < ceph_dentry(last)->offset) { if (list_empty(&parent->d_subdirs)) goto out_unlock; p = parent->d_subdirs.prev; -- 2.7.4