CVE-2025-21873: Linux kernel · scsi: ufs: core: bsg: Fix crash when arpmb command fails
Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 29 Oct 2026, 23:15 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Mar 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
AI-suggested
The vulnerability has been resolved in the Linux kernel. Users should apply the official kernel updates that include the fix for this issue. Since this is a kernel-level vulnerability, updating to a patched kernel version is the recommended mitigation. No additional workarounds or mitigations are indicated.
Description
A vulnerability in the Linux kernel's SCSI UFS core bsg subsystem could cause a crash when the arpmb command fails. This occurs because the kernel attempts to copy user data even if the device does not support arpmb, leading to a crash in bsg_transport_sg_io_fn(). The issue is triggered when ufs_bsg_exec_advanced_rpmb_req() returns an error but the job's reply length is still set.
References
- nvd.nist.gov/vuln/detail/CVE-2025-21873 (opens in a new tab)
- git.kernel.org/stable/c/32fb5ec825f6f76bc28902181c65429a904a07fe (opens in a new tab)
- git.kernel.org/stable/c/59455f968c1004ed897ba873237657745d81ce0f (opens in a new tab)
- git.kernel.org/stable/c/7e3c96ff5c5f3206984ed077b2aa8c9b7c4e0327 (opens in a new tab)
- git.kernel.org/stable/c/f27a95845b01e86d67c8b014b4f41bd3327daa63 (opens in a new tab)