{ "dataType": "CVE_RECORD", "cveMetadata": { "cveId": "CVE-2024-26640", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-19T14:20:24.137Z", "datePublished": "2024-03-18T10:19:07.025Z", "dateUpdated": "2026-08-05T11:26:27.948Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:26:27.948Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: add sanity checks to rx zerocopy\n\nTCP rx zerocopy intent is to map pages initially allocated\nfrom NIC drivers, not pages owned by a fs.\n\nThis patch adds to can_map_frag() these additional checks:\n\n- Page must not be a compound one.\n- page->mapping must be NULL.\n\nThis fixes the panic reported by ZhangPeng.\n\nsyzbot was able to loopback packets built with sendfile(),\nmapping pages owned by an ext4 file to TCP rx zerocopy.\n\nr3 = socket$inet_tcp(0x2, 0x1, 0x0)\nmmap(&(0x7f0000ff9000/0x4000)=nil, 0x4000, 0x0, 0x12, r3, 0x0)\nr4 = socket$inet_tcp(0x2, 0x1, 0x0)\nbind$inet(r4, &(0x7f0000000000)={0x2, 0x4e24, @multicast1}, 0x10)\nconnect$inet(r4, &(0x7f00000006c0)={0x2, 0x4e24, @empty}, 0x10)\nr5 = openat$dir(0xffffffffffffff9c, &(0x7f00000000c0)='./file0\\x00',\n 0x181e42, 0x0)\nfallocate(r5, 0x0, 0x0, 0x85b8)\nsendfile(r4, r5, 0x0, 0x8ba0)\ngetsockopt$inet_tcp_TCP_ZEROCOPY_RECEIVE(r4, 0x6, 0x23,\n &(0x7f00000001c0)={&(0x7f0000ffb000/0x3000)=nil, 0x3000, 0x0, 0x0, 0x0,\n 0x0, 0x0, 0x0, 0x0}, &(0x7f0000000440)=0x40)\nr6 = openat$dir(0xffffffffffffff9c, &(0x7f00000000c0)='./file0\\x00',\n 0x181e42, 0x0)" } ], "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 - Triggering requires local syscalls on the attacker's own process — mmap() of a TCP socket, sendfile() of a page-cache-backed file over loopback, and getsockopt(TCP_ZEROCOPY_RECEIVE). A purely remote peer cannot supply page-cache or compound pages into the receive frags, since those come from the local NIC/page_pool allocator.\nAC:L - The syzbot reproducer is fully deterministic with no race window and no dependence on memory layout: sendfile() guarantees PAGE_SIZE frags at offset 0 pointing at ext4 page-cache pages, and loopback delivers them unchanged to the same socket's receive queue. Follow-on inode eviction is likewise triggered on demand by the attacker via O_TRUNC/unlink+close.\nPR:L - Every step is available to an ordinary unprivileged user — tcp_mmap() performs no capability check, TCP_ZEROCOPY_RECEIVE is unconditionally compiled in under CONFIG_MMU, and sendfile() on a file the user owns needs no privilege. No CAP_NET_ADMIN or namespace trickery is required at all.\nUI:N - A single unprivileged process performs the entire sequence against itself via a loopback self-connect; no victim process must be running, and no administrator or user action is needed.\nS:U - The corruption is confined to the kernel's own page-cache/rmap accounting and the attacking process's address space, managed by the same security authority. There is no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - Because the page is mapped outside the inode's i_mmap tree, filemap_unaccount_folio()'s recovery path resets mapcount and subtracts the PTE's reference, letting the page be freed and reallocated while the attacker retains a valid read-only PTE to it — an arbitrary-read window into whatever kernel data (slab objects, page tables, other processes' pages) subsequently occupies that physical page.\nI:H - The dropped reference plus the later munmap-time page_remove_rmap()/put_page() drives _mapcount and the page refcount negative, producing a double-free of a buddy-allocator page that can be handed out twice and used as a write primitive into kernel-owned memory. The mismatched rmap/_nr_pages_mapped accounting for compound folios corrupts kernel state directly.\nA:H - This is exactly the reported crash — truncating the file makes filemap_unaccount_folio() hit VM_BUG_ON_FOLIO(folio_mapped(folio)) and panic the kernel; on non-DEBUG_VM builds it produces \"BUG: Bad page cache\"/bad-page-state taints and freelist corruption that destabilizes the whole system." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv4/tcp.c" ], "versions": [ { "version": "93ab6cc69162775201587cc9da00d5016dc890e2", "lessThan": "f48bf9a83b1666d934247cb58a9887d7b3127b6f", "status": "affected", "versionType": "git" }, { "version": "93ab6cc69162775201587cc9da00d5016dc890e2", "lessThan": "718f446e60316bf606946f7f42367d691d21541e", "status": "affected", "versionType": "git" }, { "version": "93ab6cc69162775201587cc9da00d5016dc890e2", "lessThan": "b383d4ea272fe5795877506dcce5aad1f6330e5e", "status": "affected", "versionType": "git" }, { "version": "93ab6cc69162775201587cc9da00d5016dc890e2", "lessThan": "d15cc0f66884ef2bed28c7ccbb11c102aa3a0760", "status": "affected", "versionType": "git" }, { "version": "93ab6cc69162775201587cc9da00d5016dc890e2", "lessThan": "1b8adcc0e2c584fec778add7777fe28e20781e60", "status": "affected", "versionType": "git" }, { "version": "93ab6cc69162775201587cc9da00d5016dc890e2", "lessThan": "577e4432f3ac810049cb7e6b71f4d96ec7c6e894", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv4/tcp.c" ], "versions": [ { "version": "4.18", "status": "affected" }, { "version": "0", "lessThan": "4.18", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.210", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.149", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.77", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.16", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.7.4", "lessThanOrEqual": "6.7.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.8", "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": "4.18", "versionEndExcluding": "5.10.210" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "5.15.149" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "6.1.77" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "6.6.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "6.7.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "6.8" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f48bf9a83b1666d934247cb58a9887d7b3127b6f" }, { "url": "https://git.kernel.org/stable/c/718f446e60316bf606946f7f42367d691d21541e" }, { "url": "https://git.kernel.org/stable/c/b383d4ea272fe5795877506dcce5aad1f6330e5e" }, { "url": "https://git.kernel.org/stable/c/d15cc0f66884ef2bed28c7ccbb11c102aa3a0760" }, { "url": "https://git.kernel.org/stable/c/1b8adcc0e2c584fec778add7777fe28e20781e60" }, { "url": "https://git.kernel.org/stable/c/577e4432f3ac810049cb7e6b71f4d96ec7c6e894" } ], "title": "tcp: add sanity checks to rx zerocopy", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CISA ADP Vulnrichment", "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-26640", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-03-18T14:20:07.780920Z" } } } ], "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:48:57.803Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T00:07:19.826Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/f48bf9a83b1666d934247cb58a9887d7b3127b6f", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/718f446e60316bf606946f7f42367d691d21541e", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/b383d4ea272fe5795877506dcce5aad1f6330e5e", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/d15cc0f66884ef2bed28c7ccbb11c102aa3a0760", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/1b8adcc0e2c584fec778add7777fe28e20781e60", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/577e4432f3ac810049cb7e6b71f4d96ec7c6e894", "tags": [ "x_transferred" ] }, { "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html", "tags": [ "x_transferred" ] } ] } ] }, "dataVersion": "5.2" }