{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-49142", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-02-26T01:49:39.269Z", "datePublished": "2025-02-26T01:55:12.823Z", "dateUpdated": "2026-08-05T08:54:03.748Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:54:03.748Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: preserve skb_end_offset() in skb_unclone_keeptruesize()\n\nsyzbot found another way to trigger the infamous WARN_ON_ONCE(delta < len)\nin skb_try_coalesce() [1]\n\nI was able to root cause the issue to kfence.\n\nWhen kfence is in action, the following assertion is no longer true:\n\nint size = xxxx;\nvoid *ptr1 = kmalloc(size, gfp);\nvoid *ptr2 = kmalloc(size, gfp);\n\nif (ptr1 && ptr2)\n\tASSERT(ksize(ptr1) == ksize(ptr2));\n\nWe attempted to fix these issues in the blamed commits, but forgot\nthat TCP was possibly shifting data after skb_unclone_keeptruesize()\nhas been used, notably from tcp_retrans_try_collapse().\n\nSo we not only need to keep same skb->truesize value,\nwe also need to make sure TCP wont fill new tailroom\nthat pskb_expand_head() was able to get from a\naddr = kmalloc(...) followed by ksize(addr)\n\nSplit skb_unclone_keeptruesize() into two parts:\n\n1) Inline skb_unclone_keeptruesize() for the common case,\n when skb is not cloned.\n\n2) Out of line __skb_unclone_keeptruesize() for the 'slow path'.\n\nWARNING: CPU: 1 PID: 6490 at net/core/skbuff.c:5295 skb_try_coalesce+0x1235/0x1560 net/core/skbuff.c:5295\nModules linked in:\nCPU: 1 PID: 6490 Comm: syz-executor161 Not tainted 5.17.0-rc4-syzkaller-00229-g4f12b742eb2b #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nRIP: 0010:skb_try_coalesce+0x1235/0x1560 net/core/skbuff.c:5295\nCode: bf 01 00 00 00 0f b7 c0 89 c6 89 44 24 20 e8 62 24 4e fa 8b 44 24 20 83 e8 01 0f 85 e5 f0 ff ff e9 87 f4 ff ff e8 cb 20 4e fa <0f> 0b e9 06 f9 ff ff e8 af b2 95 fa e9 69 f0 ff ff e8 95 b2 95 fa\nRSP: 0018:ffffc900063af268 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: 00000000ffffffd5 RCX: 0000000000000000\nRDX: ffff88806fc05700 RSI: ffffffff872abd55 RDI: 0000000000000003\nRBP: ffff88806e675500 R08: 00000000ffffffd5 R09: 0000000000000000\nR10: ffffffff872ab659 R11: 0000000000000000 R12: ffff88806dd554e8\nR13: ffff88806dd9bac0 R14: ffff88806dd9a2c0 R15: 0000000000000155\nFS: 00007f18014f9700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000000020002000 CR3: 000000006be7a000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n \n tcp_try_coalesce net/ipv4/tcp_input.c:4651 [inline]\n tcp_try_coalesce+0x393/0x920 net/ipv4/tcp_input.c:4630\n tcp_queue_rcv+0x8a/0x6e0 net/ipv4/tcp_input.c:4914\n tcp_data_queue+0x11fd/0x4bb0 net/ipv4/tcp_input.c:5025\n tcp_rcv_established+0x81e/0x1ff0 net/ipv4/tcp_input.c:5947\n tcp_v4_do_rcv+0x65e/0x980 net/ipv4/tcp_ipv4.c:1719\n sk_backlog_rcv include/net/sock.h:1037 [inline]\n __release_sock+0x134/0x3b0 net/core/sock.c:2779\n release_sock+0x54/0x1b0 net/core/sock.c:3311\n sk_wait_data+0x177/0x450 net/core/sock.c:2821\n tcp_recvmsg_locked+0xe28/0x1fd0 net/ipv4/tcp.c:2457\n tcp_recvmsg+0x137/0x610 net/ipv4/tcp.c:2572\n inet_recvmsg+0x11b/0x5e0 net/ipv4/af_inet.c:850\n sock_recvmsg_nosec net/socket.c:948 [inline]\n sock_recvmsg net/socket.c:966 [inline]\n sock_recvmsg net/socket.c:962 [inline]\n ____sys_recvmsg+0x2c4/0x600 net/socket.c:2632\n ___sys_recvmsg+0x127/0x200 net/socket.c:2674\n __sys_recvmsg+0xe2/0x1a0 net/socket.c:2704\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x44/0xae" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable skb_unclone_keeptruesize() path is reached while processing peer TCP behavior—incoming SACKs/ACKs drive skb_prepare_for_shift/tcp_trim_head, and withheld ACKs drive retransmit collapse—so a remote TCP peer can trigger it against a data-sending service.\nAC:L - The attacker controls connection traffic (SACK patterns, ACK withholding, retransmit pressure) that drives the unclone and collapse sequences; under a KFENCE-enabled deployment they can retry until a sampled allocation produces the size mismatch.\nPR:N - No privileges or authentication are required—only an unauthenticated TCP session to a service that sends data (for example an internet-facing server), after which crafted peer packets exercise the vulnerable path.\nUI:N - Exploitation needs no victim user action beyond the already-running network service accepting and sending on the TCP connection.\nS:U - Impact stays within the same kernel networking authority; this is not a VM escape, IOMMU bypass, or other cross-boundary break.\nC:N - The bug desynchronizes skb accounting metadata and trips WARN_ON_ONCE in skb_try_coalesce; it does not provide a usable kernel memory read or info-disclosure primitive.\nI:N - Extra tailroom comes from a legitimately larger kmalloc/ksize allocation rather than an out-of-bounds write or UAF, so there is no practical arbitrary-write or control-flow hijack primitive.\nA:H - The desync triggers WARN_ON_ONCE(delta < len) (crash under panic_on_warn) and corrupts sk_buff/socket memory accounting, enabling connection or host denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/skbuff.h", "net/core/skbuff.c" ], "versions": [ { "version": "097b9146c0e26aabaa6ff3e5ea536a53f5254a79", "lessThan": "23629b673b780d967b88a850b1518cf0f0ffc6aa", "status": "affected", "versionType": "git" }, { "version": "097b9146c0e26aabaa6ff3e5ea536a53f5254a79", "lessThan": "a9a6d30264327d8ff7f23da33e7a77ffb793fa3f", "status": "affected", "versionType": "git" }, { "version": "097b9146c0e26aabaa6ff3e5ea536a53f5254a79", "lessThan": "a903e516f5df44b46d526b403d93e7be1a425538", "status": "affected", "versionType": "git" }, { "version": "097b9146c0e26aabaa6ff3e5ea536a53f5254a79", "lessThan": "2b88cba55883eaafbc9b7cbff0b2c7cdba71ed01", "status": "affected", "versionType": "git" }, { "version": "7118945cdf0d4b5a76eb4f5f330ac6f48d372025", "status": "affected", "versionType": "git" }, { "version": "ec697f7f3f6a89d4dd1af113587d0330b5a033e8", "status": "affected", "versionType": "git" }, { "version": "7582edf28f5d1f0a4d2f7abdb7d9560d09fd41b5", "status": "affected", "versionType": "git" }, { "version": "5d55a6a46a7f70bc1d270c50200edd3096cb380c", "status": "affected", "versionType": "git" }, { "version": "e6af7cb64b7b37b8a371acdbe33a636496ffb5a4", "status": "affected", "versionType": "git" }, { "version": "97ff09a7ed484fef2b1bbc103857444b7332fca8", "status": "affected", "versionType": "git" }, { "version": "bf5a58d143d7899d2c89e585be6e98ec81fe9683", "status": "affected", "versionType": "git" }, { "version": "4.4.260", "lessThan": "4.5", "status": "affected", "versionType": "semver" }, { "version": "4.9.260", "lessThan": "4.10", "status": "affected", "versionType": "semver" }, { "version": "4.14.224", "lessThan": "4.15", "status": "affected", "versionType": "semver" }, { "version": "4.19.179", "lessThan": "4.20", "status": "affected", "versionType": "semver" }, { "version": "5.4.103", "lessThan": "5.5", "status": "affected", "versionType": "semver" }, { "version": "5.10.21", "lessThan": "5.11", "status": "affected", "versionType": "semver" }, { "version": "5.11.4", "lessThan": "5.12", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/skbuff.h", "net/core/skbuff.c" ], "versions": [ { "version": "5.12", "status": "affected" }, { "version": "0", "lessThan": "5.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.33", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.16.19", "lessThanOrEqual": "5.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.17.2", "lessThanOrEqual": "5.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.18", "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": "5.12", "versionEndExcluding": "5.15.33" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "5.16.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "5.17.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "5.18" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4.260" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.260" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14.224" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.21" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11.4" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/23629b673b780d967b88a850b1518cf0f0ffc6aa" }, { "url": "https://git.kernel.org/stable/c/a9a6d30264327d8ff7f23da33e7a77ffb793fa3f" }, { "url": "https://git.kernel.org/stable/c/a903e516f5df44b46d526b403d93e7be1a425538" }, { "url": "https://git.kernel.org/stable/c/2b88cba55883eaafbc9b7cbff0b2c7cdba71ed01" } ], "title": "net: preserve skb_end_offset() in skb_unclone_keeptruesize()", "x_generator": { "engine": "bippy-1.2.0" } } } }