{"id":"DEBIAN-CVE-2025-38066","details":"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 \u003c\u003cEOF \u003e\u003e cmeta.xml \u003csuperblock uuid=\"\" block_size=\"128\" nr_cache_blocks=\"512\" \\ policy=\"smq\" hint_width=\"4\"\u003e   \u003cmappings\u003e     \u003cmapping cache_block=\"0\" origin_block=\"0\" dirty=\"false\"/\u003e   \u003c/mappings\u003e \u003c/superblock\u003e 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=$(dd if=/dev/sdc bs=1c count=8 skip=192 \\ 2\u003e/dev/null | hexdump -e '1/8 \"%u\\n\"') ablock=$(dd if=/dev/sdc bs=1c count=8 skip=$((4096*mapping_root+2056)) \\ 2\u003e/dev/null | hexdump -e '1/8 \"%u\\n\"') dd if=/dev/zero of=/dev/sdc bs=4k count=1 seek=$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.","modified":"2026-09-01T16:06:13.521542752Z","published":"2025-06-18T10:15:39.620Z","upstream":["CVE-2025-38066"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2025-38066"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.147-1"}]}],"versions":["6.1.106-1","6.1.106-2","6.1.106-3","6.1.112-1","6.1.115-1","6.1.119-1","6.1.123-1","6.1.124-1","6.1.128-1","6.1.129-1","6.1.133-1","6.1.135-1","6.1.137-1","6.1.139-1","6.1.140-1","6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1","6.1.90-1~bpo11+1","6.1.94-1","6.1.94-1~bpo11+1","6.1.98-1","6.1.99-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-38066.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.32-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-38066.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.32-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-38066.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}