{"id":"CVE-2026-80536","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-80536","summary":"xfs: bounds-check buffer log item's dirty bitmap","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: bounds-check buffer log item's dirty bitmap\n\nxlog_recover_do_reg_buffer() replays each dirty region described by a\nbuffer log item's bitmap into the buffer read for that item:\n\n\tmemcpy(xfs_buf_offset(bp, (uint)bit << XFS_BLF_SHIFT),\n\t\titem->ri_buf[i].iov_base,\n\t\tnbits << XFS_BLF_SHIFT);\n\nThe destination offset (bit/nbits, from the logged dirty bitmap) and the\nbuffer size (from the logged blf_len) are both attacker-controlled and\notherwise unrelated, yet the only thing bounding the copy is an ASSERT(),\nwhich compiles away on production kernels. A crafted image logging a\nsmall blf_len together with a bitmap bit past the end of that buffer\ndrives the memcpy() past the buffer's allocation, corrupting adjacent\nkernel heap during mount-time log recovery. This is reachable by anyone\nwho can get a crafted image mounted -- the malicious-filesystem threat\nmodel XFS already guards against elsewhere.\n\nTurn the ASSERT() into a real XFS_IS_CORRUPT() check that aborts recovery\nof the buffer with -EFSCORRUPTED, consistent with the validate-and-fail\nidiom already used in xlog_recover_do_inode_buffer() and\nxfs_dquot_item_recover.c. xlog_recover_do_reg_buffer() therefore becomes\nSTATIC int and its three callers propagate the error.\n\nFound and confirmed with KASAN on a CONFIG_XFS_DEBUG=n build: the crafted\nimage trips a slab-out-of-bounds write before this change and fails\nrecovery cleanly with -EFSCORRUPTED after it.","published":"2026-08-26T14:37:11.584Z","modified":"2026-08-28T03:47:24.199439625Z","cvss":{"score":8.4,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"5.10.267"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/7e32d4eebae6ca24f8a673c107fd7eca1f47afc2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/813f8136a2ce1fee266d02a7df73db6e8a541604"},{"type":"WEB","url":"https://git.kernel.org/stable/c/acb4e26295e7f0e685815a3fd3d70bd8329cefa1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b7528b42813f02724a78fce1da24d69d1bfc4d38"},{"type":"WEB","url":"https://git.kernel.org/stable/c/edaf5b6bd625356893da20d69a259b34a9de2694"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f3859c35a4fbc1c1c58431f684f808e43696891d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f7b5fa83e2c192be922121b764415fa8c7549ea1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f8288214459ead7e87d26e5822f62c14a4f2ed6b"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80536.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80536"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-28T03:47:24.199439625Z"}}