oss-sec mailing list archives
Re: CVE-2021-20226 kernel: use-after-free in io_uring feature
From: Greg KH <greg () kroah com>
Date: Mon, 8 Feb 2021 13:28:57 +0100
On Mon, Feb 08, 2021 at 03:00:18PM +0530, Rohit Keshri wrote:
Hello, The flaw CVE-2021-20226 is identified as a use-after-free problem with breach to data integrity, confidentiality and system availability, and this may even cause escalated privileges with good troubleshooting skills. I also wanted to add that the affected souce (as was reported for kernel v5.7.0) has been modified from v5.10 kernel version with patch 233295130e53 with following cleanup details. ~~~ $ git show 233295130e53 commit 233295130e53c8dfe6dbef3f52634c3f7e44cd6a Author: Pavel Begunkov <asml.silence () gmail com> Date: Sat Oct 10 18:34:06 2020 +0100 io_uring: clean up ->files grabbing Move work.files grabbing into io_prep_async_work() to all other work resources initialisation. We don't need to keep it separately now, as ->ring_fd/file are gone. It also allows to not grab it when a request is not going to io-wq. .. $ git tag --contains 233295130e53 v5.10 v5.10-rc1 v5.10-rc2 v5.10-rc3 v5.10-rc4 v5.10-rc5 v5.10-rc6 v5.10-rc7 v5.11-rc1 v5.11-rc2 v5.11-rc3 v5.11-rc4 v5.11-rc5 v5.11-rc6 v5.11-rc7
That's odd, don't use `git tag --contains`, the better thing to do is: $ git describes --contains 233295130e53 v5.10-rc1~167^2~10 Which means is showed up in the tree in the 5.10-rc1 release, so anything newer than that is fine. Note, this does not include tests for backports to stable kernel releases or distro kernels. That kind of query is left as an exercise for the reader :) Hope this helps, greg k-h
Current thread:
- CVE-2021-20226 kernel: use-after-free in io_uring feature Rohit Keshri (Feb 05)
- Re: CVE-2021-20226 kernel: use-after-free in io_uring feature Alex Gaynor (Feb 05)
- Re: CVE-2021-20226 kernel: use-after-free in io_uring feature Rohit Keshri (Feb 08)
- Re: CVE-2021-20226 kernel: use-after-free in io_uring feature Greg KH (Feb 08)
- Re: CVE-2021-20226 kernel: use-after-free in io_uring feature Rohit Keshri (Feb 08)
- Re: CVE-2021-20226 kernel: use-after-free in io_uring feature Salvatore Bonaccorso (Feb 05)
- Re: CVE-2021-20226 kernel: use-after-free in io_uring feature Alex Gaynor (Feb 05)