| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2023-52895: io_uring/poll: don't reissue in case of poll race on multishot request |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| io_uring/poll: don't reissue in case of poll race on multishot request |
| |
| A previous commit fixed a poll race that can occur, but it's only |
| applicable for multishot requests. For a multishot request, we can safely |
| ignore a spurious wakeup, as we never leave the waitqueue to begin with. |
| |
| A blunt reissue of a multishot armed request can cause us to leak a |
| buffer, if they are ring provided. While this seems like a bug in itself, |
| it's not really defined behavior to reissue a multishot request directly. |
| It's less efficient to do so as well, and not required to rearm anything |
| like it is for singleshot poll requests. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52895 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.1.7 with commit c06015ebc4367be38904b88582e13cc079672075 and fixed in 6.1.8 with commit 36fc7317cdb16cfeae0f879916995037bb615ac4 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2023-52895 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| io_uring/poll.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/36fc7317cdb16cfeae0f879916995037bb615ac4 |
| https://git.kernel.org/stable/c/8caa03f10bf92cb8657408a6ece6a8a73f96ce13 |
