Messages in this thread | | | Date | Tue, 2 Aug 2022 21:09:34 -0700 | From | Eric Biggers <> | Subject | Re: [syzbot] KASAN: use-after-free Read in post_one_notification |
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On Wed, Aug 03, 2022 at 09:34:10AM +0530, Siddh Raman Pant wrote: > On Wed, 03 Aug 2022 03:57:19 +0530 Eric Biggers <ebiggers@kernel.org> wrote: > > It appears this was already fixed, so no need for any more activity on this bug: > > > > #syz fix: watchqueue: make sure to serialize 'wqueue->defunct' properly > > > > - Eric > > It doesn't address the dangling pointer remaining in the watch_queue, > which was the root cause of this crash. The use-after-free happened > because the pipe was freed but a dangling pointer of it remained in > a watch_queue, and an attempt to dereference it was there. >
I don't think that's true; the pointer doesn't get dereferenced after watch_queue::defunct is set. See my message on the other thread where I explained this: https://lore.kernel.org/lkml/YunKlJCDlmyn2hJ4@sol.localdomain
Of course, if you actually have a reproducer, or a KASAN report, or anything at all that shows there is still a problem, then please post it.
- Eric
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