CVE-2026-31580
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: ```…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/2d6965581e164fa2ba3f7652ddae5535f6336576Patch
- https://git.kernel.org/stable/c/383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9Patch
- https://git.kernel.org/stable/c/47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1Patch
- https://git.kernel.org/stable/c/4f71c8ba2dc009042493021d94a9718fbe2ebf27Patch
- https://git.kernel.org/stable/c/81f44ed8c3f54abb7561ece774ea4cca5070b2f2
- https://git.kernel.org/stable/c/9467d360be70e6ee55b0c1cd2a1f1424f57b5b85
- https://git.kernel.org/stable/c/add4982510f3b7c318a2dd7438bdc9c63171e753Patch
- https://git.kernel.org/stable/c/f50e7c325ab1207fe941555bcff659f6d7050572
- https://git.kernel.org/stable/c/fec114a98b8735ee89c75216c45a78e28be0f128Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.