{"id":"CVE-2026-74518","revision":"ebfb05ec4843407f8085ea61845ba24e","records":[{"revision":"ebfb05ec4843407f8085ea61845ba24e","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-74518","aliases":[],"title":"mm/hugetlb: fix list corruption in allocate_file_region_entries()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix list corruption in allocate_file_region_entries()\n\nallocate_file_region_entries() tops up resv->region_cache with freshly\nallocated file_region descriptors. The allocation uses GFP_KERNEL, so\nresv->lock is dropped around it: the new entries are gathered on a\nstack-local list head, allocated_regions, and spliced into\nresv->region_cache once the lock is re-acquired.\n\nThe splice used list_splice(), which moves the entries but does not\nre-initialize the source head, so allocated_regions is left pointing at an\nentry that now lives on resv->region_cache. The top-up runs in a while\nloop that re-checks the cache deficit after re-acquiring the lock. For a\nshared mapping the resv_map is shared by every mapper of the hugetlbfs\ninode, so a concurrent region_chg()/region_add()/region_del() on the same\nresv_map can consume cache entries during the unlocked window and force a\nsecond iteration. That iteration calls list_add() on the stale head and\ncorrupts the list; with CONFIG_DEBUG_LIST the __list_add_valid() check\ntrips:\n\n list_add corruption. next->prev should be prev (ffffc900011ff7f8),\n but was ffff88814c281460. (next=ffff88814c545640).\n kernel BUG at lib/list_debug.c:31!\n allocate_file_region_entries+0x191/0x420\n region_chg+0x267/0x300\n hugetlb_reserve_pages+0x387/0xc80\n hugetlbfs_file_mmap+0x2ce/0x3f0\n mmap_region+0x1348/0x1a80\n do_mmap+0x85e/0xb90\n vm_mmap_pgoff+0x18c/0x330\n ksys_mmap_pgoff+0x2a1/0x3e0\n do_syscall_64+0xd7/0x420\n\nWithout CONFIG_DEBUG_LIST the bad list_add() silently links a kernel-stack\naddress into resv->region_cache, leading to later use-after-free.\n\nThis was observed as a real host panic on a dense KVM host where a QEMU\nguest-RAM hugetlbfs file was mapped MAP_SHARED by both QEMU and a separate\nSPDK/DPDK vhost-user target, generating concurrent region_* traffic on one\nshared resv_map.\n\nUse list_splice_init() so the source head is re-initialized empty after\neach splice, making the retry loop safe.","state":0,"publishedAt":"2026-08-15T12:27:37.48+00:00","modifiedAt":"2026-10-16T19:05:52.396+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"mm/hugetlb.c\"\n ],\n \"versions\": [\n {\n \"version\": \"d3ec7b6e09e512ba902b86bcca2c512fb06d492f\",\n \"lessThan\": \"01b8569233e47693d6ff7efa96d9854c55f936fc\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3ec7b6e09e512ba902b86bcca2c512fb06d492f\",\n \"lessThan\": \"9c5fdffc5e1ce84403c58289ee72697051803bf7\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3ec7b6e09e512ba902b86bcca2c512fb06d492f\",\n \"lessThan\": \"f3e54f6a5e1681f83d13e8716bc92ef5ecf121d3\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3ec7b6e09e512ba902b86bcca2c512fb06d492f\",\n \"lessThan\": \"62e1c2741a4d923d9854efd5927a6212aad7a187\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3ec7b6e09e512ba902b86bcca2c512fb06d492f\",\n \"lessThan\": \"587a0accc2b4fccc5cf7baf0fe34e50efde51f9c\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3ec7b6e09e512ba902b86bcca2c512fb06d492f\",\n \"lessThan\": \"126a70bf1a08ddc9d79c471ebdaa2b08cfbab8df\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3ec7b6e09e512ba902b86bcca2c512fb06d492f\",\n \"lessThan\": \"ac1bb7fd45088d0db57a22ce7729f258ebd63cf5\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"d3ec7b6e09e512ba902b86bcca2c512fb06d492f\",\n \"lessThan\": \"dd9623f58ec702a07b2d67179d6fcea79c52231a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"mm/hugetlb.c\"\n ],\n \"versions\": [\n {\n \"version\": \"5.10\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"5.10\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.265\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.216\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.183\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.151\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.103\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.44\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.1.8\",\n \"lessThanOrEqual\": \"7.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/01b8569233e47693d6ff7efa96d9854c55f936fc","https://git.kernel.org/stable/c/9c5fdffc5e1ce84403c58289ee72697051803bf7","https://git.kernel.org/stable/c/f3e54f6a5e1681f83d13e8716bc92ef5ecf121d3","https://git.kernel.org/stable/c/62e1c2741a4d923d9854efd5927a6212aad7a187","https://git.kernel.org/stable/c/587a0accc2b4fccc5cf7baf0fe34e50efde51f9c","https://git.kernel.org/stable/c/126a70bf1a08ddc9d79c471ebdaa2b08cfbab8df","https://git.kernel.org/stable/c/ac1bb7fd45088d0db57a22ce7729f258ebd63cf5","https://git.kernel.org/stable/c/dd9623f58ec702a07b2d67179d6fcea79c52231a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74518","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-74518","identifiers":["CVE-2026-74518"]},"retained":false,"historicalAffected":[]}],"coverage":[]}