{"id":"CVE-2026-98095","summary":"af_packet: Don't cast tpacket_hdr.tp_len to int in tpacket_parse_header().","details":"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 \u003e 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 \u003c0f\u003e 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 \u003cTASK\u003e\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 \u003c48\u003e 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 \u003c/TASK\u003e","modified":"2026-09-26T03:48:28.029970560Z","published":"2026-09-25T10:24:26.493Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98095.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/72abe77e88c3f1f71c5348124e9b28e285f26950"},{"type":"WEB","url":"https://git.kernel.org/stable/c/73e594c19b4f815d8343461cec7074c4713bbde7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9d714076ff398ba8cc5ae0ae146f4a1ea0bbf5e8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c6b3db727876a027013aa4ccb6913a153a2af41a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98095.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98095"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1"},{"fixed":"c6b3db727876a027013aa4ccb6913a153a2af41a"},{"fixed":"72abe77e88c3f1f71c5348124e9b28e285f26950"},{"fixed":"9d714076ff398ba8cc5ae0ae146f4a1ea0bbf5e8"},{"fixed":"73e594c19b4f815d8343461cec7074c4713bbde7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98095.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.31"},{"fixed":"6.12.111"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.53"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98095.json"}}],"schema_version":"1.9.0"}