CVE-2026-53160: misc: fastrpc: fix use-after-free race in fastrpc_map_create

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-25 · updated 2026-07-06
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: fix use-after-free race in fastrpc_map_create fastrpc_map_lookup returns a raw pointer after releasing fl->lock. The caller fastrpc_map_create then calls fastrpc_map_get (kref_get_unless_zero) on this unprotected pointer. A concurrent MEM_UNMAP can free the map between the lock release and the kref operation, resulting in a use-after-free on the freed slab object. Restore the take_ref parameter to fastrpc_map_lookup so the reference is acquired atomically under fl->lock before the pointer is exposed to the caller.

Affected products

Linux kernel: from 6.1.156 before 6.1.176; from 6.6.112 before 6.6.143; from 6.12.53 before 6.12.94; from 6.17.3 before 6.18.36; from 6.19 before 7.0.13; 7.1-rc1, 7.1-rc2, 7.1-rc3, 7.1-rc4, 7.1-rc5, 7.1-rc6 (+1) — fixed in 6.1.176, 6.12.94, 6.18.36, 6.6.143, 7.0.13

How to fix

Upgrade to a fixed version: Linux kernel 6.1.176, 6.12.94, 6.18.36, 6.6.143. Check the vendor advisory for mitigations.

References

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