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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2018-05-01 13:12:14 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-03 11:23:07 +0200
commita0fbcaf9993ea291955ead3dac4b52457b3ec799 (patch)
treeddd5ee774d3b245ed3ac7d61e846a9fb97766390 /fs
parentebdc37febe594035d8cf3f5424ce97a926d2cddf (diff)
fuse: don't keep dead fuse_conn at fuse_fill_super().
commit 543b8f8662fe6d21f19958b666ab0051af9db21a upstream. syzbot is reporting use-after-free at fuse_kill_sb_blk() [1]. Since sb->s_fs_info field is not cleared after fc was released by fuse_conn_put() when initialization failed, fuse_kill_sb_blk() finds already released fc and tries to hold the lock. Fix this by clearing sb->s_fs_info field after calling fuse_conn_put(). [1] https://syzkaller.appspot.com/bug?id=a07a680ed0a9290585ca424546860464dd9658db Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+ec3986119086fe4eec97@syzkaller.appspotmail.com> Fixes: 3b463ae0c626 ("fuse: invalidation reverse calls") Cc: John Muir <john@jmuir.com> Cc: Csaba Henk <csaba@gluster.com> Cc: Anand Avati <avati@redhat.com> Cc: <stable@vger.kernel.org> # v2.6.31 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/fuse/inode.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 6fe6a88ecb4a..f95e1d49b048 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1184,6 +1184,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
err_put_conn:
fuse_bdi_destroy(fc);
fuse_conn_put(fc);
+ sb->s_fs_info = NULL;
err_fput:
fput(file);
err: