| 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-2023-52811: scsi: ibmvfc: Remove BUG_ON in the case of an empty event pool |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| scsi: ibmvfc: Remove BUG_ON in the case of an empty event pool |
| |
| In practice the driver should never send more commands than are allocated |
| to a queue's event pool. In the unlikely event that this happens, the code |
| asserts a BUG_ON, and in the case that the kernel is not configured to |
| crash on panic returns a junk event pointer from the empty event list |
| causing things to spiral from there. This BUG_ON is a historical artifact |
| of the ibmvfc driver first being upstreamed, and it is well known now that |
| the use of BUG_ON is bad practice except in the most unrecoverable |
| scenario. There is nothing about this scenario that prevents the driver |
| from recovering and carrying on. |
| |
| Remove the BUG_ON in question from ibmvfc_get_event() and return a NULL |
| pointer in the case of an empty event pool. Update all call sites to |
| ibmvfc_get_event() to check for a NULL pointer and perfrom the appropriate |
| failure or recovery action. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52811 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.15.140 with commit e1d1f79b1929dce470a5dc9281c574cd58e8c6c0 |
| Fixed in 6.1.64 with commit 88984ec4792766df5a9de7a2ff2b5f281f94c7d4 |
| Fixed in 6.5.13 with commit d2af4ef80601224b90630c1ddc7cd2c7c8ab4dd8 |
| Fixed in 6.6.3 with commit 8bbe784c2ff28d56ca0c548aaf3e584edc77052d |
| Fixed in 6.7 with commit b39f2d10b86d0af353ea339e5815820026bca48f |
| |
| 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-2023-52811 |
| 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: |
| drivers/scsi/ibmvscsi/ibmvfc.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/e1d1f79b1929dce470a5dc9281c574cd58e8c6c0 |
| https://git.kernel.org/stable/c/88984ec4792766df5a9de7a2ff2b5f281f94c7d4 |
| https://git.kernel.org/stable/c/d2af4ef80601224b90630c1ddc7cd2c7c8ab4dd8 |
| https://git.kernel.org/stable/c/8bbe784c2ff28d56ca0c548aaf3e584edc77052d |
| https://git.kernel.org/stable/c/b39f2d10b86d0af353ea339e5815820026bca48f |
