{"cve":"CVE-2026-98095","nvd":{"published":"2026-09-25T11:17:39.243","modified":"2026-10-23T18:15:25.107","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\naf_packet: Don't cast tpacket_hdr.tp_len to int in tpacket_parse_header().\n\nsyzbot reported BUG() in sock_sendmsg_nosec(). [0]\n\nThe problem is that tpacket_parse_header() casts user-provided\ntpacket_hdr.tp_len, which is u32, to int.\n\nIf the length is larger than INT_MAX, the following condition\nin tpacket_parse_header() passes,\n\n  if (unlikely(tp_len > size_max))\n\nand any negative value can be returned to the caller, up to\nsock_sendmsg_nosec().\n\nThe repro set tpacket_hdr.tp_len to 0xfffffdef, which is cast\nto -EIOCBQUEUED (-529), triggering BUG() in sock_sendmsg_nosec().\n\n  *(uint64_t*)0x200000000008 = 0xfffffdef;\n  ...\n  syscall(__NR_write, /*fd=*/r[0], /*buf=*/0x200000000000ul, /*count=*/1ul);\n\nLet's define the local tp_len as u32 in tpacket_parse_header().\n\n[0]:\nkernel BUG at net/socket.c:803!\nOops: invalid opcode: 0000 [#1] SMP KASAN PTI\nCPU: 0 UID: 0 PID: 5628 Comm: syz-executor176 Not tainted syzkaller #0 PREEMPT(full)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026\nRIP: 0010:sock_sendmsg_nosec+0x145/0x180 net/socket.c:803\nCode: 06 67 48 0f b9 3a eb 95 e8 e8 3a 22 f8 48 89 df 4c 89 f6 4c 89 e2 4d 89 fb 2e e8 32 a5 5c 16 e9 51 ff ff ff e8 cc 3a 22 f8 90 <0f> 0b e8 c4 3a 22 f8 48 83 c3 18 48 89 d8 48 c1 e8 03 42 80 3c 28\nRSP: 0018:ffffc90003aefb48 EFLAGS: 00010293\nRAX: ffffffff89a578d4 RBX: ffff8880764c67c0 RCX: ffff88807fb23e80\nRDX: 0000000000000000 RSI: 00000000fffffdef RDI: 00000000fffffdef\nRBP: 00000000fffffdef R08: ffffc90003aef747 R09: 1ffff9200075dee8\nR10: dffffc0000000000 R11: fffff5200075dee9 R12: 0000000000000001\nR13: dffffc0000000000 R14: ffffc90003aefbc0 R15: ffffffff8aac4310\nFS:  000055559101b400(0000) GS:ffff888124ce0000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000200000000210 CR3: 0000000073dca000 CR4: 00000000003526f0\nCall Trace:\n <TASK>\n __sock_sendmsg net/socket.c:815 [inline]\n sock_write_iter+0x2de/0x3e0 net/socket.c:1266\n new_sync_write fs/read_write.c:595 [inline]\n vfs_write+0x612/0xba0 fs/read_write.c:687\n ksys_write+0x150/0x270 fs/read_write.c:739\n do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]\n do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f173130ecb9\nCode: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 d8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007ffd67e44248 EFLAGS: 00000246 ORIG_RAX: 0000000000000001\nRAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f173130ecb9\nRDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000003\nRBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd67e44388\nR13: 0000000000000002 R14: 00002000000000c0 R15: 0000000000000002\n </TASK>","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-681"],"references":["https://git.kernel.org/stable/c/09e3c9b32434600a6992e762bf0d6837f5902134","https://git.kernel.org/stable/c/2b9fa12fbdbfc0f671ff23b0ea06c177a6b8a6b8","https://git.kernel.org/stable/c/3e0cad1432a0c0564f5076bab16f1aa4c0474be4","https://git.kernel.org/stable/c/6d4d55f75fa0ea32d874eb33e356e9361f3e4591","https://git.kernel.org/stable/c/72abe77e88c3f1f71c5348124e9b28e285f26950"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-24T16:53:35.584907681+00:00"},"epss":{"cve":"CVE-2026-98095","score":0.00123,"percentile":0.02006,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}