CVE-2026-74482

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74482", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.904Z", "datePublished": "2026-08-15T12:27:15.083Z", "dateUpdated": "2026-10-16T19:05:49.129Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:37:38.544Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios\n\n__folio_split() keeps dereferencing the mapping after the split:\nshmem_uncharge(mapping->host) and remap_page() while the folios are still\nfrozen/locked, and i_mmap_unlock_read(mapping) at the very end, after the\nafter-split folios have been unlocked and freed.\n\nNothing holds an inode reference across that. The split relies on @folio\n-- which the beyond-EOF drop loop never removes, as it starts at\nfolio_next(folio) -- staying locked and in the page cache to hold off\neviction. But the unlock loop unlocks @folio before i_mmap_unlock_read()\nruns. If the caller's @lock_at is a tail beyond EOF, as memory_failure()\npasses when splitting a poisoned tail of a shmem THP that reaches past\ni_size during truncation, it too is gone from the page cache; so once\n@folio is unlocked no locked, in-cache folio pins the inode, and a\nconcurrent final iput() can evict and RCU-free it before\ni_mmap_unlock_read() touches i_mmap_rwsem:\n\n BUG: KASAN: slab-use-after-free in __up_read+0x634/0x790\n i_mmap_unlock_read include/linux/fs.h:537 [inline]\n __folio_split+0x732/0x1640 mm/huge_memory.c:4100\n try_to_split_thp_page+0xab/0x390 mm/memory-failure.c:1675\n memory_failure+0x1394/0x26e0 mm/memory-failure.c:2470\n\n Freed by task 4601:\n shmem_free_in_core_inode+0x54/0xb0 mm/shmem.c:5177\n evict+0x57f/0xac0 fs/inode.c:870\n\nDo every mapping dereference while @folio still pins the inode: drop\ni_mmap_rwsem right after remap_page(), before the loop that unlocks and\nfrees the after-split folios, and clear @mapping so the exit path does not\nunlock it again. shmem_uncharge() and remap_page() already run before\nthat point, so after this nothing past the unlock loop touches the inode\nor the mapping.\n\nThis is now a rule the split depends on, alongside keeping @folio frozen\nuntil the page cache is updated: no inode or mapping dereference once the\nafter-split folios start being unlocked."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The UAF is in __folio_split() on the memory_failure()->try_to_split_thp_page() path while splitting file-backed shmem THPs; reachability is via local syscalls (memfd/mmap/madvise/ftruncate) or admin hwpoison injection, not network or physical interfaces.\nAC:L - An attacker can deterministically create a shmem THP with tail pages beyond EOF and race MADV_HWPOISON-driven memory_failure() against concurrent truncate/close(iput) using attacker-controlled threads; both sides of the race are attacker-driven.\nPR:L - Reliable exploitation uses MADV_HWPOISON to invoke memory_failure() on a chosen tail page; CAP_SYS_ADMIN is available to user-namespace/container root, and the shmem THP setup needs only ordinary local mapping and truncation privileges.\nUI:N - No separate victim action is required; the attacker creates, maps, poisons, and truncates their own memfd/shmem/tmpfs object to reach the vulnerable split path.\nS:U - Impact is a kernel slab use-after-free on inode/mapping metadata in core MM within the same kernel security domain, not a VM escape, sandbox breakout, or other cross-authority boundary violation.\nC:H - KASAN reports slab-use-after-free in i_mmap_unlock_read() after shmem_free_in_core_inode() RCU-frees the inode; this inode/mapping UAF can be heap-sprayed into an arbitrary kernel memory read primitive.\nI:H - The same UAF corrupts freed inode slab objects and i_mmap_rwsem state, enabling heap grooming for arbitrary kernel writes and potential privilege escalation via control-flow hijacking per kernel UAF guidance.\nA:H - The use-after-free provokes a KASAN BUG/oops during i_mmap_unlock_read() and corrupts core MM inode state, capable of kernel panic or hang when triggered on production shmem/tmpfs workloads."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["mm/huge_memory.c"], "versions": [{"version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "bc2f5eabaaf60ec18da70b619a8fba1bfb7dea3a", "status": "affected", "versionType": "git"}, {"version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "f87c08060818ebb19bafed37c38244538da25097", "status": "affected", "versionType": "git"}, {"version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "6f5c272d71845a669e4c8ee5c72b376e29a0e6e5", "status": "affected", "versionType": "git"}, {"version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "be106f7855f03d3128ed0ce70ba74b484a90b473", "status": "affected", "versionType": "git"}, {"version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "e3dd774dbfd0b5bc2dbd0995221751b1234f8205", "status": "affected", "versionType": "git"}, {"version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "10065fb891651d9541e7a5a2db84c1e656ece4f9", "status": "affected", "versionType": "git"}, {"version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "d640efe94d86d3be893d4c19220362546a637e90", "status": "affected", "versionType": "git"}, {"version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "e923bd21058ea02fd0dcd3549d151d143fd036e5", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["mm/huge_memory.c"], "versions": [{"version": "4.8", "status": "affected"}, {"version": "0", "lessThan": "4.8", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.8", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "5.10.265"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "5.15.216"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.1.183"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.6.151"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.12.103"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "6.18.44"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "7.1.8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.8", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/bc2f5eabaaf60ec18da70b619a8fba1bfb7dea3a"}, {"url": "https://git.kernel.org/stable/c/f87c08060818ebb19bafed37c38244538da25097"}, {"url": "https://git.kernel.org/stable/c/6f5c272d71845a669e4c8ee5c72b376e29a0e6e5"}, {"url": "https://git.kernel.org/stable/c/be106f7855f03d3128ed0ce70ba74b484a90b473"}, {"url": "https://git.kernel.org/stable/c/e3dd774dbfd0b5bc2dbd0995221751b1234f8205"}, {"url": "https://git.kernel.org/stable/c/10065fb891651d9541e7a5a2db84c1e656ece4f9"}, {"url": "https://git.kernel.org/stable/c/d640efe94d86d3be893d4c19220362546a637e90"}, {"url": "https://git.kernel.org/stable/c/e923bd21058ea02fd0dcd3549d151d143fd036e5"}], "title": "mm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74482", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T18:57:49.050841Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:05:49.129Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74482", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T18:57:49.050841Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T18:57:49.963Z"}}], "cna": {"title": "mm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 7.8, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:L - The UAF is in __folio_split() on the memory_failure()->try_to_split_thp_page() path while splitting file-backed shmem THPs; reachability is via local syscalls (memfd/mmap/madvise/ftruncate) or admin hwpoison injection, not network or physical interfaces.\nAC:L - An attacker can deterministically create a shmem THP with tail pages beyond EOF and race MADV_HWPOISON-driven memory_failure() against concurrent truncate/close(iput) using attacker-controlled threads; both sides of the race are attacker-driven.\nPR:L - Reliable exploitation uses MADV_HWPOISON to invoke memory_failure() on a chosen tail page; CAP_SYS_ADMIN is available to user-namespace/container root, and the shmem THP setup needs only ordinary local mapping and truncation privileges.\nUI:N - No separate victim action is required; the attacker creates, maps, poisons, and truncates their own memfd/shmem/tmpfs object to reach the vulnerable split path.\nS:U - Impact is a kernel slab use-after-free on inode/mapping metadata in core MM within the same kernel security domain, not a VM escape, sandbox breakout, or other cross-authority boundary violation.\nC:H - KASAN reports slab-use-after-free in i_mmap_unlock_read() after shmem_free_in_core_inode() RCU-frees the inode; this inode/mapping UAF can be heap-sprayed into an arbitrary kernel memory read primitive.\nI:H - The same UAF corrupts freed inode slab objects and i_mmap_rwsem state, enabling heap grooming for arbitrary kernel writes and potential privilege escalation via control-flow hijacking per kernel UAF guidance.\nA:H - The use-after-free provokes a KASAN BUG/oops during i_mmap_unlock_read() and corrupts core MM inode state, capable of kernel panic or hang when triggered on production shmem/tmpfs workloads."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "bc2f5eabaaf60ec18da70b619a8fba1bfb7dea3a", "versionType": "git"}, {"status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "f87c08060818ebb19bafed37c38244538da25097", "versionType": "git"}, {"status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "6f5c272d71845a669e4c8ee5c72b376e29a0e6e5", "versionType": "git"}, {"status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "be106f7855f03d3128ed0ce70ba74b484a90b473", "versionType": "git"}, {"status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "e3dd774dbfd0b5bc2dbd0995221751b1234f8205", "versionType": "git"}, {"status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "10065fb891651d9541e7a5a2db84c1e656ece4f9", "versionType": "git"}, {"status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "d640efe94d86d3be893d4c19220362546a637e90", "versionType": "git"}, {"status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "lessThan": "e923bd21058ea02fd0dcd3549d151d143fd036e5", "versionType": "git"}], "programFiles": ["mm/huge_memory.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.8"}, {"status": "unaffected", "version": "0", "lessThan": "4.8", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.265", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.216", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.183", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.151", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.103", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.44", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.8", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["mm/huge_memory.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/bc2f5eabaaf60ec18da70b619a8fba1bfb7dea3a"}, {"url": "https://git.kernel.org/stable/c/f87c08060818ebb19bafed37c38244538da25097"}, {"url": "https://git.kernel.org/stable/c/6f5c272d71845a669e4c8ee5c72b376e29a0e6e5"}, {"url": "https://git.kernel.org/stable/c/be106f7855f03d3128ed0ce70ba74b484a90b473"}, {"url": "https://git.kernel.org/stable/c/e3dd774dbfd0b5bc2dbd0995221751b1234f8205"}, {"url": "https://git.kernel.org/stable/c/10065fb891651d9541e7a5a2db84c1e656ece4f9"}, {"url": "https://git.kernel.org/stable/c/d640efe94d86d3be893d4c19220362546a637e90"}, {"url": "https://git.kernel.org/stable/c/e923bd21058ea02fd0dcd3549d151d143fd036e5"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios\n\n__folio_split() keeps dereferencing the mapping after the split:\nshmem_uncharge(mapping->host) and remap_page() while the folios are still\nfrozen/locked, and i_mmap_unlock_read(mapping) at the very end, after the\nafter-split folios have been unlocked and freed.\n\nNothing holds an inode reference across that. The split relies on @folio\n-- which the beyond-EOF drop loop never removes, as it starts at\nfolio_next(folio) -- staying locked and in the page cache to hold off\neviction. But the unlock loop unlocks @folio before i_mmap_unlock_read()\nruns. If the caller's @lock_at is a tail beyond EOF, as memory_failure()\npasses when splitting a poisoned tail of a shmem THP that reaches past\ni_size during truncation, it too is gone from the page cache; so once\n@folio is unlocked no locked, in-cache folio pins the inode, and a\nconcurrent final iput() can evict and RCU-free it before\ni_mmap_unlock_read() touches i_mmap_rwsem:\n\n BUG: KASAN: slab-use-after-free in __up_read+0x634/0x790\n i_mmap_unlock_read include/linux/fs.h:537 [inline]\n __folio_split+0x732/0x1640 mm/huge_memory.c:4100\n try_to_split_thp_page+0xab/0x390 mm/memory-failure.c:1675\n memory_failure+0x1394/0x26e0 mm/memory-failure.c:2470\n\n Freed by task 4601:\n shmem_free_in_core_inode+0x54/0xb0 mm/shmem.c:5177\n evict+0x57f/0xac0 fs/inode.c:870\n\nDo every mapping dereference while @folio still pins the inode: drop\ni_mmap_rwsem right after remap_page(), before the loop that unlocks and\nfrees the after-split folios, and clear @mapping so the exit path does not\nunlock it again. shmem_uncharge() and remap_page() already run before\nthat point, so after this nothing past the unlock loop touches the inode\nor the mapping.\n\nThis is now a rule the split depends on, alongside keeping @folio frozen\nuntil the page cache is updated: no inode or mapping dereference once the\nafter-split folios start being unlocked."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.265", "versionStartIncluding": "4.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.216", "versionStartIncluding": "4.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.183", "versionStartIncluding": "4.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.151", "versionStartIncluding": "4.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.103", "versionStartIncluding": "4.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.44", "versionStartIncluding": "4.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.8", "versionStartIncluding": "4.8"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "4.8"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:37:38.544Z"}}}, "cveMetadata": {"cveId": "CVE-2026-74482", "state": "PUBLISHED", "dateUpdated": "2026-10-16T19:05:49.129Z", "dateReserved": "2026-08-15T05:44:03.904Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-15T12:27:15.083Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["mm/huge_memory.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "bc2f5eabaaf60ec18da70b619a8fba1bfb7dea3a", "status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "versionType": "git"}, {"lessThan": "f87c08060818ebb19bafed37c38244538da25097", "status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "versionType": "git"}, {"lessThan": "6f5c272d71845a669e4c8ee5c72b376e29a0e6e5", "status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "versionType": "git"}, {"lessThan": "be106f7855f03d3128ed0ce70ba74b484a90b473", "status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "versionType": "git"}, {"lessThan": "e3dd774dbfd0b5bc2dbd0995221751b1234f8205", "status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "versionType": "git"}, {"lessThan": "10065fb891651d9541e7a5a2db84c1e656ece4f9", "status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "versionType": "git"}, {"lessThan": "d640efe94d86d3be893d4c19220362546a637e90", "status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "versionType": "git"}, {"lessThan": "e923bd21058ea02fd0dcd3549d151d143fd036e5", "status": "affected", "version": "baa355fd331424526e742d41d9b90d5f9d10f716", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["mm/huge_memory.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.8"}, {"lessThan": "4.8", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.265", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.216", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.183", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.151", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.103", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.44", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.8", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios\n\n__folio_split() keeps dereferencing the mapping after the split:\nshmem_uncharge(mapping->host) and remap_page() while the folios are still\nfrozen/locked, and i_mmap_unlock_read(mapping) at the very end, after the\nafter-split folios have been unlocked and freed.\n\nNothing holds an inode reference across that. The split relies on @folio\n-- which the beyond-EOF drop loop never removes, as it starts at\nfolio_next(folio) -- staying locked and in the page cache to hold off\neviction. But the unlock loop unlocks @folio before i_mmap_unlock_read()\nruns. If the caller's @lock_at is a tail beyond EOF, as memory_failure()\npasses when splitting a poisoned tail of a shmem THP that reaches past\ni_size during truncation, it too is gone from the page cache; so once\n@folio is unlocked no locked, in-cache folio pins the inode, and a\nconcurrent final iput() can evict and RCU-free it before\ni_mmap_unlock_read() touches i_mmap_rwsem:\n\n BUG: KASAN: slab-use-after-free in __up_read+0x634/0x790\n i_mmap_unlock_read include/linux/fs.h:537 [inline]\n __folio_split+0x732/0x1640 mm/huge_memory.c:4100\n try_to_split_thp_page+0xab/0x390 mm/memory-failure.c:1675\n memory_failure+0x1394/0x26e0 mm/memory-failure.c:2470\n\n Freed by task 4601:\n shmem_free_in_core_inode+0x54/0xb0 mm/shmem.c:5177\n evict+0x57f/0xac0 fs/inode.c:870\n\nDo every mapping dereference while @folio still pins the inode: drop\ni_mmap_rwsem right after remap_page(), before the loop that unlocks and\nfrees the after-split folios, and clear @mapping so the exit path does not\nunlock it again. shmem_uncharge() and remap_page() already run before\nthat point, so after this nothing past the unlock loop touches the inode\nor the mapping.\n\nThis is now a rule the split depends on, alongside keeping @folio frozen\nuntil the page cache is updated: no inode or mapping dereference once the\nafter-split folios start being unlocked."}], "id": "CVE-2026-74482", "lastModified": "2026-10-16T20:17:31.267", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-74482", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T18:57:49.050841Z", "version": "2.0.3"}}]}, "published": "2026-08-15T13:17:53.053", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/10065fb891651d9541e7a5a2db84c1e656ece4f9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6f5c272d71845a669e4c8ee5c72b376e29a0e6e5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bc2f5eabaaf60ec18da70b619a8fba1bfb7dea3a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/be106f7855f03d3128ed0ce70ba74b484a90b473"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d640efe94d86d3be893d4c19220362546a637e90"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e3dd774dbfd0b5bc2dbd0995221751b1234f8205"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e923bd21058ea02fd0dcd3549d151d143fd036e5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f87c08060818ebb19bafed37c38244538da25097"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: mm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios", "id": "2517056", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2517056"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nmm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios\n__folio_split() keeps dereferencing the mapping after the split:\nshmem_uncharge(mapping->host) and remap_page() while the folios are still\nfrozen/locked, and i_mmap_unlock_read(mapping) at the very end, after the\nafter-split folios have been unlocked and freed.\nNothing holds an inode reference across that. The split relies on @folio\n-- which the beyond-EOF drop loop never removes, as it starts at\nfolio_next(folio) -- staying locked and in the page cache to hold off\neviction. But the unlock loop unlocks @folio before i_mmap_unlock_read()\nruns. If the caller's @lock_at is a tail beyond EOF, as memory_failure()\npasses when splitting a poisoned tail of a shmem THP that reaches past\ni_size during truncation, it too is gone from the page cache; so once\n@folio is unlocked no locked, in-cache folio pins the inode, and a\nconcurrent final iput() can evict and RCU-free it before\ni_mmap_unlock_read() touches i_mmap_rwsem:\nBUG: KASAN: slab-use-after-free in __up_read+0x634/0x790\ni_mmap_unlock_read include/linux/fs.h:537 [inline]\n__folio_split+0x732/0x1640 mm/huge_memory.c:4100\ntry_to_split_thp_page+0xab/0x390 mm/memory-failure.c:1675\nmemory_failure+0x1394/0x26e0 mm/memory-failure.c:2470\nFreed by task 4601:\nshmem_free_in_core_inode+0x54/0xb0 mm/shmem.c:5177\nevict+0x57f/0xac0 fs/inode.c:870\nDo every mapping dereference while @folio still pins the inode: drop\ni_mmap_rwsem right after remap_page(), before the loop that unlocks and\nfrees the after-split folios, and clear @mapping so the exit path does not\nunlock it again. shmem_uncharge() and remap_page() already run before\nthat point, so after this nothing past the unlock loop touches the inode\nor the mapping.\nThis is now a rule the split depends on, alongside keeping @folio frozen\nuntil the page cache is updated: no inode or mapping dereference once the\nafter-split folios start being unlocked.", "A flaw was found in the Linux kernel's huge memory management (mm/huge_memory). A race condition exists in the `__folio_split()` function where the `i_mmap_rwsem` lock is released prematurely before all after-split folios are fully processed. This allows a concurrent operation to free the inode while subsequent memory management operations attempt to access it, leading to a use-after-free vulnerability. This can result in system instability or a denial of service."], "name": "CVE-2026-74482", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74482\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74482\nhttps://lore.kernel.org/linux-cve-announce/2026081537-CVE-2026-74482-571b@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[baa355fd331424526e742d41d9b90d5f9d10f716,be106f7855f03d3128ed0ce70ba74b484a90b473)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[baa355fd331424526e742d41d9b90d5f9d10f716,e3dd774dbfd0b5bc2dbd0995221751b1234f8205)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[baa355fd331424526e742d41d9b90d5f9d10f716,d640efe94d86d3be893d4c19220362546a637e90)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[baa355fd331424526e742d41d9b90d5f9d10f716,e923bd21058ea02fd0dcd3549d151d143fd036e5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[baa355fd331424526e742d41d9b90d5f9d10f716,10065fb891651d9541e7a5a2db84c1e656ece4f9)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "4.8"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,4.8)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.151,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.103,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.44,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.8,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc6,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-15T15:45:06.744639+00:00", "updated": "2026-08-21T20:45:03.860326+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-416", "CWE-825"]}