Messages in this thread Patch in this message | | | Subject | Re: KASAN: use-after-free Read in fuse_kill_sb_blk | From | Tetsuo Handa <> | Date | Tue, 1 May 2018 19:03:05 +0900 |
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From 606d54cd24b5b00e7a7e3597aabbe89719defc56 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Date: Tue, 1 May 2018 13:12:14 +0900 Subject: [PATCH] fuse: don't keep dead fuse_conn at fuse_fill_super().
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: 3b463ae0c6264f70 ("fuse: invalidation reverse calls") Cc: John Muir <john@jmuir.com> Cc: Csaba Henk <csaba@gluster.com> Cc: Anand Avati <avati@redhat.com> Cc: Miklos Szeredi <mszeredi@redhat.com> --- fs/fuse/inode.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index ef30995..9b37cf8 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1179,6 +1179,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) fuse_dev_free(fud); err_put_conn: fuse_conn_put(fc); + sb->s_fs_info = NULL; err_fput: fput(file); err: -- 1.8.3.1
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