Re: CVE-2020-29373 reproducer fails on v5.11

[Petr Vorel <pvorel@suse.cz>]

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.

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/