CVE-2026-31580
bcache: fix cached_dev.sb_bio use-after-free and crash
In the Linux kernel, the following vulnerability has been resolved: bcache: fix cached_dev.sb_bio use-after-free and crash In our production environment, we have received multiple crash reports regarding libceph, which have caught our attention: ``` [6888366.280350] Call Trace: [6888366.280452] blk_update_request+0x14e/0x370 [6888366.280561] blk_mq_end_request+0x1a/0x130 [6888366.280671] rbd_img_handle_request+0x1a0/0x1b0 [rbd] [6888366.280792] rbd_obj_handle_request+0x32/0x40 [rbd] [6888366.280903] __complete_request+0x22/0x70 [libceph] [6888366.281032] osd_dispatch+0x15e/0xb40 [libceph] [6888366.281164] ? inet_recvmsg+0x5b/0xd0 [6888366.281272] ? ceph_tcp_recvmsg+0x6f/0xa0 [libceph] [6888366.281405] ceph_con_process_message+0x79/0x140 [libceph] [6888366.281534] ceph_con_v1_try_read+0x5d7/0xf30 [libceph] [6888366.281661] ceph_con_workfn+0x329/0x680 [libceph] ``` After analyzing the coredump file, we found that the address of dc->sb_bio has been freed. We know that cached_dev is only freed when it is stopped. Since sb_bio is a part of struct cached_dev, rather than an alloc every time. If the device is stopped while writing to the superblock, the released address will be accessed at endio. This patch hopes to wait for sb_write to complete in cached_dev_free. It should be noted that we analyzed the cause of the problem, then tell all details to the QWEN and adopted the modifications it made.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| Linux Linux |
≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060; < 81f44ed8c3f54abb7561ece774ea4cca5070b2f2 (affected, git) ≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060; < f50e7c325ab1207fe941555bcff659f6d7050572 (affected, git) ≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060; < 9467d360be70e6ee55b0c1cd2a1f1424f57b5b85 (affected, git) ≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060; < 47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1 (affected, git) ≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060; < add4982510f3b7c318a2dd7438bdc9c63171e753 (affected, git) ≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060; < 2d6965581e164fa2ba3f7652ddae5535f6336576 (affected, git) ≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060; < 4f71c8ba2dc009042493021d94a9718fbe2ebf27 (affected, git) ≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060; < 383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9 (affected, git) ≥ cafe563591446cf80bfbc2fe3bc72a2e36cf1060; < fec114a98b8735ee89c75216c45a78e28be0f128 (affected, git) Other versions: unaffected |
CNA: Linux |
| Linux Linux |
3.10 (affected) ≥ 0; < 3.10 (unaffected, semver) ≥ 5.10.258; ≤ 5.10.* (unaffected, semver) ≥ 5.15.209; ≤ 5.15.* (unaffected, semver) ≥ 6.1.175; ≤ 6.1.* (unaffected, semver) ≥ 6.6.136; ≤ 6.6.* (unaffected, semver) ≥ 6.12.83; ≤ 6.12.* (unaffected, semver) ≥ 6.18.24; ≤ 6.18.* (unaffected, semver) ≥ 6.19.14; ≤ 6.19.* (unaffected, semver) ≥ 7.0.1; ≤ 7.0.* (unaffected, semver) ≥ 7.1; ≤ * (unaffected, original_commit_for_fix) Other versions: affected |
CNA: Linux |
| SIMATIC S7-1500 TM MFP - GNU/Linux subsystem Siemens |
≥ 0; < * (affected, custom)
Other versions: unknown |
ADP: siemens-SADP |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
No CVSS assessment reported. An unscored record is not a low-severity determination.
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://git.kernel.org/stable/c/81f44ed8c3f54abb7561ece774ea4cca5070b2f2CNA: Linux
- https://git.kernel.org/stable/c/f50e7c325ab1207fe941555bcff659f6d7050572CNA: Linux
- https://git.kernel.org/stable/c/9467d360be70e6ee55b0c1cd2a1f1424f57b5b85CNA: Linux
- https://git.kernel.org/stable/c/47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1CNA: Linux
- https://git.kernel.org/stable/c/add4982510f3b7c318a2dd7438bdc9c63171e753CNA: Linux
- https://git.kernel.org/stable/c/2d6965581e164fa2ba3f7652ddae5535f6336576CNA: Linux
- https://git.kernel.org/stable/c/4f71c8ba2dc009042493021d94a9718fbe2ebf27CNA: Linux
- https://git.kernel.org/stable/c/383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9CNA: Linux
- https://git.kernel.org/stable/c/fec114a98b8735ee89c75216c45a78e28be0f128CNA: Linux
- https://cert-portal.siemens.com/productcert/html/ssa-784472.htmlADP: siemens-SADP
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