CVE-2026-31580
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BaseFortify
Vulnerability report for CVE-2026-31580, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-04-24
Last updated on: 2026-06-01
Assigner: kernel.org
Description
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 Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | From 6.13 (inc) to 6.18.24 (exc) |
| linux | linux_kernel | From 6.19 (inc) to 6.19.14 (exc) |
| linux | linux_kernel | From 7.0 (inc) to 7.0.1 (exc) |
| linux | linux_kernel | to 6.6.136 (exc) |
| linux | linux_kernel | From 6.12 (inc) to 6.12.83 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
