# CVE-2021-47369: linux: In the Linux kernel, the following vulnerability has been resolved: s390/qeth: fix NULL deref in qeth_clear_working_... CVE-2021-47369 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47369, released May 21, 2024. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2021-47369 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0024 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 21, 2024 ## Description In the Linux kernel, the following vulnerability has been resolved: s390/qeth: fix NULL deref in qeth_clear_working_pool_list() When qeth_set_online() calls qeth_clear_working_pool_list() to roll back after an error exit from qeth_hardsetup_card(), we are at risk of accessing card->qdio.in_q before it was allocated by qeth_alloc_qdio_queues() via qeth_mpc_initialize(). qeth_clear_working_pool_list() then dereferences NULL, and by writing to queue->bufs[i].pool_entry scribbles all over the CPU's lowcore. Resulting in a crash when those lowcore areas are used next (eg. on the next machine-check interrupt). Such a scenario would typically happen when the device is first set online and its queues aren't allocated yet. An early IO error or certain misconfigs (eg. mismatched transport mode, bad portno) then cause us to error out from qeth_hardsetup_card() with card->qdio.in_q still being NULL. Fix it by checking the pointer for NULL before accessing it. Note that we also have (rare) paths inside qeth_mpc_initialize() where a configuration change can cause us to free the existing queues, expecting that subsequent code will allocate them again. If we then error out before that re-allocation happens, the same bug occurs. Root-caused-by: Heiko Carstens ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | linux Debian 12.15 (bookworm) | 5.14.9-1 | [DEBIAN-CVE-2021-47369](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47369.md) | May 21, 2024 | | Linux | linux Debian 13.5 (trixie) | 5.14.9-1 | [DEBIAN-CVE-2021-47369](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47369.md) | May 21, 2024 | | Linux | linux Debian 14 | 5.14.9-1 | [DEBIAN-CVE-2021-47369](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47369.md) | May 21, 2024 | --- Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.