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.
Affected products
linux: linux kernel
References10
- git.kernel.org/stable/c/2d6965581e164fa2ba3f7652ddae5535f6336576 Patch
- git.kernel.org/stable/c/383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9 Patch
- git.kernel.org/stable/c/47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1 Patch
- git.kernel.org/stable/c/4f71c8ba2dc009042493021d94a9718fbe2ebf27 Patch
- git.kernel.org/stable/c/add4982510f3b7c318a2dd7438bdc9c63171e753 Patch
- git.kernel.org/stable/c/fec114a98b8735ee89c75216c45a78e28be0f128 Patch
- git.kernel.org/stable/c/81f44ed8c3f54abb7561ece774ea4cca5070b2f2
- git.kernel.org/stable/c/9467d360be70e6ee55b0c1cd2a1f1424f57b5b85
- git.kernel.org/stable/c/f50e7c325ab1207fe941555bcff659f6d7050572
- cert-portal.siemens.com/productcert/html/ssa-784472.html
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 3 · as of 13 November 2026
- CWE
- CWE-416
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