CVE-2026-31580

Description

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.

Gravité et risque d'exploitation

CVE-2026-31580 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.13 %, ce qui la place devant 2.4 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, <=7.0.*, <=6.12.*, <81f44ed8c3f54abb7561ece774ea4cca5070b2f2, 0, 6.12.83, 7.0.1, cafe563591446cf80bfbc2fe3bc72a2e36cf1060, 5.15.209, <3.10, <=5.10.*, <=6.6.*, 6.1.175, <=6.19.*, 6.6.136, <fec114a98b8735ee89c75216c45a78e28be0f128, <2d6965581e164fa2ba3f7652ddae5535f6336576, <f50e7c325ab1207fe941555bcff659f6d7050572, 7.1, <=6.18.*, <9467d360be70e6ee55b0c1cd2a1f1424f57b5b85, 5.10.258, <add4982510f3b7c318a2dd7438bdc9c63171e753, <=*, 6.19.14, <=5.15.*, 3.10, <4f71c8ba2dc009042493021d94a9718fbe2ebf27, <47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1, <383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9, 6.18.24) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/81f44ed8c3f54abb7561ece774ea4cca5070b2f2
• https://git.kernel.org/stable/c/f50e7c325ab1207fe941555bcff659f6d7050572
• https://git.kernel.org/stable/c/9467d360be70e6ee55b0c1cd2a1f1424f57b5b85
• https://git.kernel.org/stable/c/47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1
• https://git.kernel.org/stable/c/add4982510f3b7c318a2dd7438bdc9c63171e753
• https://git.kernel.org/stable/c/2d6965581e164fa2ba3f7652ddae5535f6336576
• https://git.kernel.org/stable/c/4f71c8ba2dc009042493021d94a9718fbe2ebf27
• https://git.kernel.org/stable/c/383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9
• https://git.kernel.org/stable/c/fec114a98b8735ee89c75216c45a78e28be0f128