{"id":"CVE-2024-57929","summary":"dm array: fix releasing a faulty array block twice in dm_array_cursor_end","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm array: fix releasing a faulty array block twice in dm_array_cursor_end\n\nWhen dm_bm_read_lock() fails due to locking or checksum errors, it\nreleases the faulty block implicitly while leaving an invalid output\npointer behind. The caller of dm_bm_read_lock() should not operate on\nthis invalid dm_block pointer, or it will lead to undefined result.\nFor example, the dm_array_cursor incorrectly caches the invalid pointer\non reading a faulty array block, causing a double release in\ndm_array_cursor_end(), then hitting the BUG_ON in dm-bufio cache_put().\n\nReproduce steps:\n\n1. initialize a cache device\n\ndmsetup create cmeta --table \"0 8192 linear /dev/sdc 0\"\ndmsetup create cdata --table \"0 65536 linear /dev/sdc 8192\"\ndmsetup create corig --table \"0 524288 linear /dev/sdc $262144\"\ndd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1\ndmsetup create cache --table \"0 524288 cache /dev/mapper/cmeta \\\n/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0\"\n\n2. wipe the second array block offline\n\ndmsteup remove cache cmeta cdata corig\nmapping_root=$(dd if=/dev/sdc bs=1c count=8 skip=192 \\\n2\u003e/dev/null | hexdump -e '1/8 \"%u\\n\"')\nablock=$(dd if=/dev/sdc bs=1c count=8 skip=$((4096*mapping_root+2056)) \\\n2\u003e/dev/null | hexdump -e '1/8 \"%u\\n\"')\ndd if=/dev/zero of=/dev/sdc bs=4k count=1 seek=$ablock\n\n3. try reopen the cache device\n\ndmsetup create cmeta --table \"0 8192 linear /dev/sdc 0\"\ndmsetup create cdata --table \"0 65536 linear /dev/sdc 8192\"\ndmsetup create corig --table \"0 524288 linear /dev/sdc $262144\"\ndmsetup create cache --table \"0 524288 cache /dev/mapper/cmeta \\\n/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0\"\n\nKernel logs:\n\n(snip)\ndevice-mapper: array: array_block_check failed: blocknr 0 != wanted 10\ndevice-mapper: block manager: array validator check failed for block 10\ndevice-mapper: array: get_ablock failed\ndevice-mapper: cache metadata: dm_array_cursor_next for mapping failed\n------------[ cut here ]------------\nkernel BUG at drivers/md/dm-bufio.c:638!\n\nFix by setting the cached block pointer to NULL on errors.\n\nIn addition to the reproducer described above, this fix can be\nverified using the \"array_cursor/damaged\" test in dm-unit:\n  dm-unit run /pdata/array_cursor/damaged --kernel-dir \u003cKERNEL_DIR\u003e","modified":"2026-03-20T12:41:04.063207Z","published":"2025-01-19T11:52:46.096Z","related":["MGASA-2025-0030","MGASA-2025-0032","SUSE-SU-2025:0289-1","SUSE-SU-2025:0428-1","SUSE-SU-2025:0499-1","SUSE-SU-2025:0557-1","SUSE-SU-2025:0565-1","SUSE-SU-2025:20165-1","SUSE-SU-2025:20166-1","SUSE-SU-2025:20248-1","SUSE-SU-2025:20249-1","USN-7379-2","USN-7380-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/57xxx/CVE-2024-57929.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/017c4470bff53585370028fec9341247bad358ff"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6002bec5354f86d1a2df21468f68e3ec03ede9da"},{"type":"WEB","url":"https://git.kernel.org/stable/c/738994872d77e189b2d13c501a1d145e95d98f46"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9c7c03d0e926762adf3a3a0ba86156fb5e19538b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e477021d252c007f0c6d45b5d13d341efed03979"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f2893c0804d86230ffb8f1c8703fdbb18648abc8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fc1ef07c3522e257e32702954f265debbcb096a7"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/57xxx/CVE-2024-57929.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-57929"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"fdd1315aa5f022fe6574efdc2d9535f75a0ee255"},{"fixed":"9c7c03d0e926762adf3a3a0ba86156fb5e19538b"},{"fixed":"fc1ef07c3522e257e32702954f265debbcb096a7"},{"fixed":"738994872d77e189b2d13c501a1d145e95d98f46"},{"fixed":"e477021d252c007f0c6d45b5d13d341efed03979"},{"fixed":"6002bec5354f86d1a2df21468f68e3ec03ede9da"},{"fixed":"017c4470bff53585370028fec9341247bad358ff"},{"fixed":"f2893c0804d86230ffb8f1c8703fdbb18648abc8"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-57929.json"}}],"schema_version":"1.7.5"}