dm array: fix releasing a faulty array block twice in dm_array_cursor_end
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 5.4.290, 5.10.234, 5.15.177, 6.1.125, 6.6.72, and 1 more
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: dm array: fix releasing a faulty array block twice in dm_array_cursor_end When dm_bm_read_lock() fails due to locking or checksum errors, it releases the faulty block implicitly while leaving an invalid output pointer behind. The caller of dm_bm_read_lock() should not operate on this invalid dm_block pointer, or it will lead to undefined result. For example, the dm_array_cursor incorrectly caches the invalid pointer on reading a faulty array block, causing a double release in dm_array_cursor_end(), then hitting the BUG_ON in dm-bufio cache_put(). Reproduce steps: 1. initialize a cache device 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 $262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" 2. wipe the second array block offline dmsteup remove cache cmeta cdata corig mapping_root=$(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 reopen the cache device 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 --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" Kernel logs: (snip) device-mapper: array: array_block_check failed: blocknr 0 != wanted 10 device-mapper: block manager: array validator check failed for block 10 device-mapper: array: get_ablock failed device-mapper: cache metadata: dm_array_cursor_next for mapping failed ------------[ cut here ]------------ kernel BUG at drivers/md/dm-bufio.c:638! Fix by setting the cached block pointer to NULL on errors. In addition to the reproducer described above, this fix can be verified using the "array_cursor/damaged" test in dm-unit: dm-unit run /pdata/array_cursor/damaged --kernel-dir <KERNEL_DIR>
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From fdd1315aa5f022fe6574efdc2d9535f75a0ee255 · fixed in 9c7c03d0e926762adf3a3a0ba86156fb5e19538b; From fdd1315aa5f022fe6574efdc2d9535f75a0ee255 · fixed in fc1ef07c3522e257e32702954f265debbcb096a7; From fdd1315aa5f022fe6574efdc2d9535f75a0ee255 · fixed in 738994872d77e189b2d13c501a1d145e95d98f46; From fdd1315aa5f022fe6574efdc2d9535f75a0ee255 · fixed in e477021d252c007f0c6d45b5d13d341efed03979; From fdd1315aa5f022fe6574efdc2d9535f75a0ee255 · fixed in 6002bec5354f86d1a2df21468f68e3ec03ede9da; From fdd1315aa5f022fe6574efdc2d9535f75a0ee255 · fixed in 017c4470bff53585370028fec9341247bad358ff; From fdd1315aa5f022fe6574efdc2d9535f75a0ee255 · fixed in f2893c0804d86230ffb8f1c8703fdbb18648abc8
- Linux Linux
4.9
- KernelLinux
From 4.9.0 · fixed in 5.4.290; From 5.5.0 · fixed in 5.10.234; From 5.11.0 · fixed in 5.15.177; From 5.16.0 · fixed in 6.1.125; From 6.2.0 · fixed in 6.6.72; From 6.7.0 · fixed in 6.12.10
References 7
git.kernel.org
- stable/c/9c7c03d0e926762adf3a3a0ba86156fb5e19538b
- stable/c/fc1ef07c3522e257e32702954f265debbcb096a7
- stable/c/738994872d77e189b2d13c501a1d145e95d98f46
- stable/c/e477021d252c007f0c6d45b5d13d341efed03979
- stable/c/6002bec5354f86d1a2df21468f68e3ec03ede9da
- stable/c/017c4470bff53585370028fec9341247bad358ff
- stable/c/f2893c0804d86230ffb8f1c8703fdbb18648abc8