On Tue, May 23, 2023 at 07:16:20PM +0200, Jason A. Donenfeld wrote: > On Tue, May 23, 2023 at 06:47:41PM +0200, Jason A. Donenfeld wrote: > > On Tue, May 23, 2023 at 6:46 PM Jakub Kicinski <k...@kernel.org> wrote: > > > > > > On Tue, 23 May 2023 18:14:18 +0200 Jason A. Donenfeld wrote: > > > > So, IOW, not a wireguard bug, right? > > > > > > What's slightly concerning is that there aren't any other timers > > > leading to > > > > > > KASAN: slab-use-after-free Write in enqueue_timer > > > > > > :( If WG was just an innocent bystander there should be, right? > > > > Well, WG does mod this timer for every single packet in its RX path. > > So that's bound to turn things up I suppose. > > Here's one that is seemingly the same -- enqueuing a timer to a freed > base -- with the allocation and free being the same netdev core > function, but the UaF trigger for it is a JBD2 transaction thing: > https://syzkaller.appspot.com/text?tag=CrashReport&x=17dd2446280000 > No WG at all in it, but there's still the mysterious 5376 value...
In this one, you see the free happens in some infiniband code. Looking at ipoib_dev_priv, and going to the member at net_device+ipoib_dev_priv, we get this at 5320: struct delayed_work neigh_reap_task; 5376-5320=56, which doesn't quite put us at the timer_list. Close but no cigar?