cbcvebase.
CVE-2025-40270
published 2025-12-06

CVE-2025-40270: In the Linux kernel, the following vulnerability has been resolved: mm, swap: fix potential UAF issue for VMA readahead Since commit 78524b05f1a3 ("mm, swap…

PriorityP338high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.13%
3.2th percentile
In the Linux kernel, the following vulnerability has been resolved: mm, swap: fix potential UAF issue for VMA readahead Since commit 78524b05f1a3 ("mm, swap: avoid redundant swap device pinning"), the common helper for allocating and preparing a folio in the swap cache layer no longer tries to get a swap device reference internally, because all callers of __read_swap_cache_async are already holding a swap entry reference. The repeated swap device pinning isn't needed on the same swap device. Caller of VMA readahead is also holding a reference to the target entry's swap device, but VMA readahead walks the page table, so it might encounter swap entries from other devices, and call __read_swap_cache_async on another device without holding a reference to it. So it is possible to cause a UAF when swapoff of device A raced with swapin on device B, and VMA readahead tries to read swap entries from device A. It's not easy to trigger, but in theory, it could cause real issues. Make VMA readahead try to get the device reference first if the swap device is a different one from the target entry.

Affected

9 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.17.9-1 (forky)linux 6.17.9-1 (forky)
linuxlinux
linuxlinux>= 78524b05f1a3e16a5d00cc9c6259c41a9d6003ce < a4145be7b56bfa87dce56415c3ad993071462b8aa4145be7b56bfa87dce56415c3ad993071462b8a
linuxlinux>= 78524b05f1a3e16a5d00cc9c6259c41a9d6003ce < 1c2a936edd71e133f2806e68324ec81a4eb075881c2a936edd71e133f2806e68324ec81a4eb07588
linuxlinux_kernel>= 0 < 6.17.9-16.17.9-1
linuxlinux_kernel>= 0 < 6.17.0-14.146.17.0-14.14
linuxlinux_kernel>= 6.15.0 < 6.17.96.17.9
ubuntulinux-aws
ubuntulinux-oracle

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vendor_redhat5.8MEDIUM
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