CVE-2017-12190

low-risk
Published 2017-11-22

The bio_map_user_iov and bio_unmap_user functions in block/bio.c in the Linux kernel before 4.13.8 do unbalanced refcounting when a SCSI I/O vector has small consecutive buffers belonging to the same page. The bio_add_pc_page function merges them into one, but the page reference is never dropped. This causes a memory leak and possible system lockup (exploitable against the host OS by a guest OS user, if a SCSI disk is passed through to a virtual machine) due to an out-of-memory condition.

Do I need to act?

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0.08% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
6
CVSS 6.5/10 Medium
LOCAL / LOW complexity

Affected Products (1)

Affected Vendors

26
/ 100
low-risk
Severity 21/34 · High
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal