From: Al Viro <viro@zeniv.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: syzbot <syzbot+7a8ba368b47fdefca61e@syzkaller.appspotmail.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: ceph: fix use-after-free on symlink traversal
Date: Tue, 26 Mar 2019 01:38:58 +0000 [thread overview]
Message-ID: <20190326013858.GU2217@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20190325233731.GS2217@ZenIV.linux.org.uk>
free the symlink body after the same RCU delay we have for freeing the
struct inode itself, so that traversal during RCU pathwalk wouldn't step
into freed memory.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index e3346628efe2..2d61ddda9bf5 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -524,6 +524,7 @@ static void ceph_i_callback(struct rcu_head *head)
struct inode *inode = container_of(head, struct inode, i_rcu);
struct ceph_inode_info *ci = ceph_inode(inode);
+ kfree(ci->i_symlink);
kmem_cache_free(ceph_inode_cachep, ci);
}
@@ -566,7 +567,6 @@ void ceph_destroy_inode(struct inode *inode)
}
}
- kfree(ci->i_symlink);
while ((n = rb_first(&ci->i_fragtree)) != NULL) {
frag = rb_entry(n, struct ceph_inode_frag, node);
rb_erase(n, &ci->i_fragtree);
next prev parent reply other threads:[~2019-03-26 1:39 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-28 17:40 KASAN: use-after-free Read in path_lookupat syzbot
2019-03-25 0:44 ` syzbot
2019-03-25 1:25 ` Linus Torvalds
2019-03-25 1:23 ` Linus Torvalds
2019-03-25 4:57 ` Al Viro
2019-03-25 9:15 ` Daniel Borkmann
2019-03-25 11:11 ` Al Viro
2019-03-25 11:17 ` Al Viro
2019-03-25 11:21 ` Daniel Borkmann
2019-03-25 18:36 ` Linus Torvalds
2019-03-25 19:18 ` Linus Torvalds
2019-03-25 21:14 ` Al Viro
2019-03-25 21:45 ` Linus Torvalds
2019-03-25 22:04 ` Daniel Borkmann
2019-03-25 22:13 ` Linus Torvalds
2019-03-25 22:41 ` Daniel Borkmann
2019-03-25 22:49 ` Al Viro
2019-03-25 23:37 ` Al Viro
2019-03-25 23:44 ` Alexei Starovoitov
2019-03-26 0:21 ` Al Viro
2019-03-26 1:38 ` Al Viro [this message]
2019-03-26 1:39 ` jffs2: fix use-after-free on symlink traversal Al Viro
2019-03-26 1:40 ` ubifs: " Al Viro
2019-03-26 1:43 ` debugfs: " Al Viro
2019-03-26 10:41 ` ceph: " Jeff Layton
2019-03-26 11:38 ` Ilya Dryomov
2019-03-26 1:45 ` KASAN: use-after-free Read in path_lookupat Al Viro
2019-04-10 18:11 ` Al Viro
2019-04-10 19:44 ` Linus Torvalds
2019-03-25 19:43 ` Al Viro
2019-03-25 22:48 ` Dave Chinner
2019-03-25 23:02 ` Al Viro
[not found] ` <CAGe7X7mb=gK7zhSwmT_6mmmkcbjhZAOb=wj31BdUcHkNUPsm2Q@mail.gmail.com>
2019-03-26 4:15 ` Al Viro
2019-03-27 16:58 ` Jan Kara
2019-03-27 18:59 ` Al Viro
2019-03-28 9:00 ` Jan Kara
2019-03-27 17:22 ` Jan Kara
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