{"id":"CVE-2023-54069","url":"https://www.cyber-defence.io/tools/cve/CVE-2023-54069","generatedAt":"2026-10-27T23:57:57.264Z","title":"In the Linux kernel, the following vulnerability has been resolved: ext4: fix BUG in ext4_mb_new_inode_pa() due to overflow When we calculate the end position of ext4_free_extent, this position may be exactly where ext4_lblk_t (i.e. uint) overflows.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix BUG in ext4_mb_new_inode_pa() due to overflow\n\nWhen we calculate the end position of ext4_free_extent, this position may\nbe exactly where ext4_lblk_t (i.e. uint) overflows. For example, if\nac_g_ex.fe_logical is 4294965248 and ac_orig_goal_len is 2048, then the\ncomputed end is 0x100000000, which is 0. If ac->ac_o_ex.fe_logical is not\nthe first case of adjusting the best extent, that is, new_bex_end > 0, the\nfollowing BUG_ON will be triggered:\n\n=========================================================\nkernel BUG at fs/ext4/mballoc.c:5116!\ninvalid opcode: 0000 [#1] PREEMPT SMP PTI\nCPU: 3 PID: 673 Comm: xfs_io Tainted: G E 6.5.0-rc1+ #279\nRIP: 0010:ext4_mb_new_inode_pa+0xc5/0x430\nCall Trace:\n <TASK>\n ext4_mb_use_best_found+0x203/0x2f0\n ext4_mb_try_best_found+0x163/0x240\n ext4_mb_regular_allocator+0x158/0x1550\n ext4_mb_new_blocks+0x86a/0xe10\n ext4_ext_map_blocks+0xb0c/0x13a0\n ext4_map_blocks+0x2cd/0x8f0\n ext4_iomap_begin+0x27b/0x400\n iomap_iter+0x222/0x3d0\n __iomap_dio_rw+0x243/0xcb0\n iomap_dio_rw+0x16/0x80\n=========================================================\n\nA simple reproducer demonstrating the problem:\n\n\tmkfs.ext4 -F /dev/sda -b 4096 100M\n\tmount /dev/sda /tmp/test\n\tfallocate -l1M /tmp/test/tmp\n\tfallocate -l10M /tmp/test/file\n\tfallocate -i -o 1M -l16777203M /tmp/test/file\n\tfsstress -d /tmp/test -l 0 -n 100000 -p 8 &\n\tsleep 10 && killall -9 fsstress\n\trm -f /tmp/test/tmp\n\txfs_io -c \"open -ad /tmp/test/file\" -c \"pwrite -S 0xff 0 8192\"\n\nWe simply refactor the logic for adjusting the best extent by adding\na temporary ext4_free_extent ex and use extent_logical_end() to avoid\noverflow, which also simplifies the code.","published":"2025-12-24T13:16:09.000Z","lastModified":"2026-06-17T06:46:45.000Z","status":"Deferred","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00209,"percentile":0.11031,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"unknown","text":"Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/58fe961c606c446f5612f6897827b1cac42c2e89","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/83ecffd40c65844a73c2e93d7c841455786605ac","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b7e9ec38b6a0beb5a49cd1e76be0a9a07c218e90","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bc056e7163ac7db945366de219745cf94f32a3e6","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f2c3a3aa6f11ad9878dbc3a067b0633e07b586c1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fcefddf3a151b2c416b20120c06bb1ba9ad676fb","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2023-54069","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}