Re: [syzbot] [netfs?] KASAN: slab-use-after-free Read in iov_iter_advance

[Hillf Danton]

On Fri, 20 Sep 2024 07:26:34 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    a430d95c5efa Merge tag 'lsm-pr-20240911' of git://git.kern..
> git tree:       upstream
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10c7d69f980000

#syz test

--- x/fs/netfs/write_collect.c
+++ y/fs/netfs/write_collect.c
@@ -548,7 +548,9 @@ void netfs_write_collection_worker(struc
 		return;
 	}
 
+	mutex_lock(&ictx->wb_lock);
 	netfs_collect_write_results(wreq);
+	mutex_unlock(&ictx->wb_lock);
 
 	/* We're done when the app thread has finished posting subreqs and all
 	 * the queues in all the streams are empty.
--