Answer in brief
CVE-2025-38066 records a Medium severity (CVSS 5.5) vulnerability in dm cache: prevent BUG_ON by blocking retries on failed device resumes. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=66a636356647a9be8885c2ce2948de126577698a <c614584c2a66b538f469089ac089457a34590c14 || >=66a636356647a9be8885c2ce2948de126577698a <c5356a5e80442131e2714d0d26bb110590e4e568 || >=66a636356647a9be8885c2ce2948de126577698a <025c8f477625eb39006ded650e7d027bcfb20e79 || >=66a636356647a9be8885c2ce2948de126577698a <00586b78eeb7c626a14ca13453a1631f88a7cf36 || >=66a636356647a9be8885c2ce2948de126577698a <3986ef4a9b6a0d9c28bc325d8713beba5e67586f || >=66a636356647a9be8885c2ce2948de126577698a <cc80a5cc520939d0a7d071cc4ae4b3c55ef171d0 || >=66a636356647a9be8885c2ce2948de126577698a <f3128e3074e8af565cc6a66fe3384a56df87f803 || >=66a636356647a9be8885c2ce2948de126577698a <5da692e2262b8f81993baa9592f57d12c2703dea | c614584c2a66b538f469089ac089457a34590c14, c5356a5e80442131e2714d0d26bb110590e4e568, 025c8f477625eb39006ded650e7d027bcfb20e79, 00586b78eeb7c626a14ca13453a1631f88a7cf36, 3986ef4a9b6a0d9c28bc325d8713beba5e67586f, cc80a5cc520939d0a7d071cc4ae4b3c55ef171d0, f3128e3074e8af565cc6a66fe3384a56df87f803, 5da692e2262b8f81993baa9592f57d12c2703dea |
| Linux/Linuxgeneric | 4.2 | Not reported |
Published upstream
Jun 18, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 5, 2026
In the Linux kernel, the following vulnerability has been resolved: dm cache: prevent BUG_ON by blocking retries on failed device resumes A cache device failing to resume due to mapping errors should not be retried, as the failure leaves a partially initialized policy object. Repeating the resume operation risks triggering BUG_ON when reloading cache mappings into the incomplete policy object. Reproduce steps: 1. create a cache metadata consisting of 512 or more cache blocks, with some mappings stored in the first array block of the mapping array. Here we use cache_restore v1.0 to build the metadata. cat <<EOF >> cmeta.xml <superblock uuid="" block_size="128" nr_cache_blocks="512" \ policy="smq" hint_width="4"> <mappings> <mapping cache_block="0" origin_block="0" dirty="false"/> </mappings> </superblock> EOF dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" cache_restore -i cmeta.xml -o /dev/mapper/cmeta --metadata-version=2 dmsetup remove cmeta 2. wipe the second array block of the mapping array to simulate data degradations. mapping_root=$(dd if=/dev/sdc bs=1c count=8 skip=192 \ 2>/dev/null | hexdump -e '1/8 "%u\n"') ablock=$(dd if=/dev/sdc bs=1c count=8 skip=$((4096*mapping_root+2056)) \ 2>/dev/null | hexdump -e '1/8 "%u\n"') dd if=/dev/zero of=/dev/sdc bs=4k count=1 seek=$ablock 3. try bringing up the cache device. The resume is expected to fail due to the broken array block. dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 65536 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dmsetup create cache --notable dmsetup load cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" dmsetup resume cache 4. try resuming the cache again. An unexpected BUG_ON is triggered while loading cache mappings. dmsetup resume cache Kernel logs: (snip) ------------[ cut here ]------------ kernel BUG at drivers/md/dm-cache-policy-smq.c:752! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 UID: 0 PID: 332 Comm: dmsetup Not tainted 6.13.4 #3 RIP: 0010:smq_load_mapping+0x3e5/0x570 Fix by disallowing resume operations for devices that failed the initial attempt.
Quoted source text, attributed separately from HOL analysis.