{"id":"CVE-2024-35877","revision":null,"records":[{"revision":"efaba95b31454460be47f733ee5119b0","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2024-35877","aliases":[],"title":"x86/mm/pat: fix VM_PAT handling in COW mappings","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm/pat: fix VM_PAT handling in COW mappings\n\nPAT handling won't do the right thing in COW mappings: the first PTE (or,\nin fact, all PTEs) can be replaced during write faults to point at anon\nfolios.  Reliably recovering the correct PFN and cachemode using\nfollow_phys() from PTEs will not work in COW mappings.\n\nUsing follow_phys(), we might just get the address+protection of the anon\nfolio (which is very wrong), or fail on swap/nonswap entries, failing\nfollow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and\ntrack_pfn_copy(), not properly calling free_pfn_range().\n\nIn free_pfn_range(), we either wouldn't call memtype_free() or would call\nit with the wrong range, possibly leaking memory.\n\nTo fix that, let's update follow_phys() to refuse returning anon folios,\nand fallback to using the stored PFN inside vma->vm_pgoff for COW mappings\nif we run into that.\n\nWe will now properly handle untrack_pfn() with COW mappings, where we\ndon't need the cachemode.  We'll have to fail fork()->track_pfn_copy() if\nthe first page was replaced by an anon folio, though: we'd have to store\nthe cachemode in the VMA to make this work, likely growing the VMA size.\n\nFor now, lets keep it simple and let track_pfn_copy() just fail in that\ncase: it would have failed in the past with swap/nonswap entries already,\nand it would have done the wrong thing with anon folios.\n\nSimple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn():\n\n<--- C reproducer --->\n #include <stdio.h>\n #include <sys/mman.h>\n #include <unistd.h>\n #include <liburing.h>\n\n int main(void)\n {\n         struct io_uring_params p = {};\n         int ring_fd;\n         size_t size;\n         char *map;\n\n         ring_fd = io_uring_setup(1, &p);\n         if (ring_fd < 0) {\n                 perror(\"io_uring_setup\");\n                 return 1;\n         }\n         size = p.sq_off.array + p.sq_entries * sizeof(unsigned);\n\n         /* Map the submission queue ring MAP_PRIVATE */\n         map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,\n                    ring_fd, IORING_OFF_SQ_RING);\n         if (map == MAP_FAILED) {\n                 perror(\"mmap\");\n                 return 1;\n         }\n\n         /* We have at least one page. Let's COW it. */\n         *map = 0;\n         pause();\n         return 0;\n }\n<--- C reproducer --->\n\nOn a system with 16 GiB RAM and swap configured:\n # ./iouring &\n # memhog 16G\n # killall iouring\n[  301.552930] ------------[ cut here ]------------\n[  301.553285] WARNING: CPU: 7 PID: 1402 at arch/x86/mm/pat/memtype.c:1060 untrack_pfn+0xf4/0x100\n[  301.553989] Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_g\n[  301.558232] CPU: 7 PID: 1402 Comm: iouring Not tainted 6.7.5-100.fc38.x86_64 #1\n[  301.558772] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebu4\n[  301.559569] RIP: 0010:untrack_pfn+0xf4/0x100\n[  301.559893] Code: 75 c4 eb cf 48 8b 43 10 8b a8 e8 00 00 00 3b 6b 28 74 b8 48 8b 7b 30 e8 ea 1a f7 000\n[  301.561189] RSP: 0018:ffffba2c0377fab8 EFLAGS: 00010282\n[  301.561590] RAX: 00000000ffffffea RBX: ffff9208c8ce9cc0 RCX: 000000010455e047\n[  301.562105] RDX: 07fffffff0eb1e0a RSI: 0000000000000000 RDI: ffff9208c391d200\n[  301.562628] RBP: 0000000000000000 R08: ffffba2c0377fab8 R09: 0000000000000000\n[  301.563145] R10: ffff9208d2292d50 R11: 0000000000000002 R12: 00007fea890e0000\n[  301.563669] R13: 0000000000000000 R14: ffffba2c0377fc08 R15: 0000000000000000\n[  301.564186] FS:  0000000000000000(0000) GS:ffff920c2fbc0000(0000) knlGS:0000000000000000\n[  301.564773] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  301.565197] CR2: 00007fea88ee8a20 CR3: 00000001033a8000 CR4: 0000000000750ef0\n[  301.565725] PKRU: 55555554\n[  301.565944] Call Trace:\n[  301.566148]  <TASK>\n[  301.566325]  ? untrack_pfn+0xf4/0x100\n[  301.566618]  ? __warn+0x81/0x130\n[  301.566876]  ? untrack_pfn+0xf4/0x100\n[  3\n---truncated---","state":0,"publishedAt":"2024-05-19T08:34:34.604+00:00","modifiedAt":"2026-10-15T00:41:06.214+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                        \"arch/x86/mm/pat/memtype.c\",\n                        \"mm/memory.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5899329b19100c0b82dc78e9b21ed8b920c9ffb3\",\n                            \"lessThan\": \"f18681daaec9665a15c5e7e0f591aad5d0ac622b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5899329b19100c0b82dc78e9b21ed8b920c9ffb3\",\n                            \"lessThan\": \"09e6bb53217bf388a0d2fd7fb21e74ab9dffc173\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5899329b19100c0b82dc78e9b21ed8b920c9ffb3\",\n                            \"lessThan\": \"c2b2430b48f3c9eaccd2c3d2ad75bb540d4952f4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5899329b19100c0b82dc78e9b21ed8b920c9ffb3\",\n                            \"lessThan\": \"7cfee26d1950250b14c5cb0a37b142f3fcc6396a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5899329b19100c0b82dc78e9b21ed8b920c9ffb3\",\n                            \"lessThan\": \"97e93367e82752e475a33839a80b33bdbef1209f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5899329b19100c0b82dc78e9b21ed8b920c9ffb3\",\n                            \"lessThan\": \"51b7841f3fe84606ec0bd8da859d22e05e5419ec\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5899329b19100c0b82dc78e9b21ed8b920c9ffb3\",\n                            \"lessThan\": \"1341e4b32e1fb1b0acd002ccd56f07bd32f2abc6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5899329b19100c0b82dc78e9b21ed8b920c9ffb3\",\n                            \"lessThan\": \"04c35ab3bdae7fefbd7c7a7355f29fa03a035221\",\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                        \"arch/x86/mm/pat/memtype.c\",\n                        \"mm/memory.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"2.6.29\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"2.6.29\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"4.19.312\",\n                            \"lessThanOrEqual\": \"4.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.4.274\",\n                            \"lessThanOrEqual\": \"5.4.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.215\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.155\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.85\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.26\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.8.5\",\n                            \"lessThanOrEqual\": \"6.8.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.9\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/f18681daaec9665a15c5e7e0f591aad5d0ac622b","https://git.kernel.org/stable/c/09e6bb53217bf388a0d2fd7fb21e74ab9dffc173","https://git.kernel.org/stable/c/c2b2430b48f3c9eaccd2c3d2ad75bb540d4952f4","https://git.kernel.org/stable/c/7cfee26d1950250b14c5cb0a37b142f3fcc6396a","https://git.kernel.org/stable/c/97e93367e82752e475a33839a80b33bdbef1209f","https://git.kernel.org/stable/c/51b7841f3fe84606ec0bd8da859d22e05e5419ec","https://git.kernel.org/stable/c/1341e4b32e1fb1b0acd002ccd56f07bd32f2abc6","https://git.kernel.org/stable/c/04c35ab3bdae7fefbd7c7a7355f29fa03a035221"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2024-35877","license":"CVE Program Terms of Use","key":"cve-program:CVE-2024-35877","identifiers":["CVE-2024-35877"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-09T21:04:24.7578035+00:00","complete":true,"records":1773,"lastAttemptAt":"2026-11-09T21:04:24.7578035+00:00","lastSuccessAt":"2026-11-09T21:04:24.9268553+00:00","error":null,"lastVerifiedAt":"2026-11-09T21:04:24.9268558+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-24e6fde7b744113daefb8f6135035fb8a5c69c9617c9c0d40574a0376532ffd3-053f9ef31f64a58e1cca81479dcc447749281d31bad8cf441e11bc47a86a0a95","complete":true,"records":421662,"lastAttemptAt":"2026-11-09T21:02:16.6599285+00:00","lastSuccessAt":"2026-11-09T21:02:16.5514646+00:00","error":null,"lastVerifiedAt":"2026-11-09T21:02:16.6599285+00:00","snapshotPublishedAt":"2026-11-09T20:28:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-c0d08c6d568c485b97f7477173a8f37a","complete":false,"records":13661,"lastAttemptAt":"2026-11-09T21:17:08.552025+00:00","lastSuccessAt":"2026-11-09T21:17:08.543+00:00","error":"19 identifier lookups failed; latest failures include HTTP 403. Other identifiers were checked independently.","lastVerifiedAt":"2026-11-09T21:17:08.543+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13205,"expectedIdentifiers":13714,"failedIdentifiers":19},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-09T21:04:24.7578035+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T21:04:24.7578035+00:00","lastSuccessAt":"2026-11-09T21:04:28.0976125+00:00","error":null,"lastVerifiedAt":"2026-11-09T21:04:28.0976126+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-0bbee8bbb4ab420e9cc5a178c14c3d7c","complete":false,"records":13673,"lastAttemptAt":"2026-11-09T21:04:53.6647083+00:00","lastSuccessAt":"2026-11-09T21:04:53.656+00:00","error":null,"lastVerifiedAt":"2026-11-09T21:04:53.656+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13704,"expectedIdentifiers":13714,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-f3867a42f9521b26d30bf45a82113d9245ec430c8ce8e24ac384524aacc94234","complete":true,"records":9916,"lastAttemptAt":"2026-11-09T21:04:24.6555906+00:00","lastSuccessAt":"2026-11-09T21:04:24.2243141+00:00","error":null,"lastVerifiedAt":"2026-11-09T21:04:24.6555906+00:00","snapshotPublishedAt":"2026-11-09T21:03:14+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-26503967ae4379db8f374089589d6e03fb15bd31f820c9e992aaf93840c2236c","complete":true,"records":1971,"lastAttemptAt":"2026-11-09T21:02:20.5882227+00:00","lastSuccessAt":"2026-11-09T21:02:20.472473+00:00","error":null,"lastVerifiedAt":"2026-11-09T21:02:20.5882227+00:00","snapshotPublishedAt":"2026-11-09T20:18:18+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-761ecc9061239b0da572dc9254c6f384c1d19339eb08408c436647a2f26129e9","complete":true,"records":3064,"lastAttemptAt":"2026-11-09T21:04:24.720759+00:00","lastSuccessAt":"2026-11-09T17:05:03.4044794+00:00","error":null,"lastVerifiedAt":"2026-11-09T21:04:24.720759+00:00","snapshotPublishedAt":"2026-11-09T16:33:20+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-2e8b7295933e7bde85a0f6f5814c210f0d64871f05755388951863da683dd321","complete":true,"records":231324,"lastAttemptAt":"2026-11-09T21:04:14.5816688+00:00","lastSuccessAt":"2026-11-09T21:04:13.103121+00:00","error":null,"lastVerifiedAt":"2026-11-09T21:04:14.5816688+00:00","snapshotPublishedAt":"2026-11-09T20:48:07+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}