Hi Pavel, > On 12/02/2021 12:49, Petr Vorel wrote: > > Hi all, > >> On 2/10/21 12:32 PM, Pavel Begunkov wrote: > >>> On 10/02/2021 19:08, Petr Vorel wrote: > >>>> Hi all, > >>>> I found that the reproducer for CVE-2020-29373 from Nicolai Stange (source attached), > >>>> which was backported to LTP as io_uring02 by Martin Doucha [1] is failing since > >>>> 10cad2c40dcb ("io_uring: don't take fs for recvmsg/sendmsg") from v5.11-rc1. > >>> Thanks for letting us know, we need to revert it > >> I'll queue up a revert. Would also be nice to turn that into > >> a liburing regression test. > > Jens (or others), could you please have look that the other commit 907d1df30a51 > > ("io_uring: fix wqe->lock/completion_lock deadlock") from v5.11-rc6 didn't cause > > any regression? Changed behavior causing io_uring02 test [1] and the original > > reproducer [2] to fail is probably a test bug, but better double check that. > Thanks for keeping an eye on it. That's on the test because DRAIN doesn't > punt to worker threads anymore, and DRAIN is used for those prepended > requests. > Can we just use IOSQE_ASYNC instead and fallback to DRAIN for older kernels > as you mentioned? It would be much more reliable. Or replace IOSQE_IO_DRAIN > with IOSQE_IO_LINK, but there are nuances to that... Thanks for your tips! Kind regards, Petr > > Kind regards, > > Petr > > [1] https://github.com/linux-test-project/ltp/tree/master/testcases/kernel/syscalls/io_uring/io_uring02.c > > [2] https://lore.kernel.org/io-uring/YCQvL8%2FDMNVLLuuf@pevik/