{"cve":"CVE-2024-36905","nvd":{"published":"2024-05-30T16:15:14.030","modified":"2026-10-15T01:18:24.700","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets\n\nTCP_SYN_RECV state is really special, it is only used by\ncross-syn connections, mostly used by fuzzers.\n\nIn the following crash [1], syzbot managed to trigger a divide\nby zero in tcp_rcv_space_adjust()\n\nA socket makes the following state transitions,\nwithout ever calling tcp_init_transfer(),\nmeaning tcp_init_buffer_space() is also not called.\n\n         TCP_CLOSE\nconnect()\n         TCP_SYN_SENT\n         TCP_SYN_RECV\nshutdown() -> tcp_shutdown(sk, SEND_SHUTDOWN)\n         TCP_FIN_WAIT1\n\nTo fix this issue, change tcp_shutdown() to not\nperform a TCP_SYN_RECV -> TCP_FIN_WAIT1 transition,\nwhich makes no sense anyway.\n\nWhen tcp_rcv_state_process() later changes socket state\nfrom TCP_SYN_RECV to TCP_ESTABLISH, then look at\nsk->sk_shutdown to finally enter TCP_FIN_WAIT1 state,\nand send a FIN packet from a sane socket state.\n\nThis means tcp_send_fin() can now be called from BH\ncontext, and must use GFP_ATOMIC allocations.\n\n[1]\ndivide error: 0000 [#1] PREEMPT SMP KASAN NOPTI\nCPU: 1 PID: 5084 Comm: syz-executor358 Not tainted 6.9.0-rc6-syzkaller-00022-g98369dccd2f8 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024\n RIP: 0010:tcp_rcv_space_adjust+0x2df/0x890 net/ipv4/tcp_input.c:767\nCode: e3 04 4c 01 eb 48 8b 44 24 38 0f b6 04 10 84 c0 49 89 d5 0f 85 a5 03 00 00 41 8b 8e c8 09 00 00 89 e8 29 c8 48 0f af c3 31 d2 <48> f7 f1 48 8d 1c 43 49 8d 96 76 08 00 00 48 89 d0 48 c1 e8 03 48\nRSP: 0018:ffffc900031ef3f0 EFLAGS: 00010246\nRAX: 0c677a10441f8f42 RBX: 000000004fb95e7e RCX: 0000000000000000\nRDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000\nRBP: 0000000027d4b11f R08: ffffffff89e535a4 R09: 1ffffffff25e6ab7\nR10: dffffc0000000000 R11: ffffffff8135e920 R12: ffff88802a9f8d30\nR13: dffffc0000000000 R14: ffff88802a9f8d00 R15: 1ffff1100553f2da\nFS:  00005555775c0380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f1155bf2304 CR3: 000000002b9f2000 CR4: 0000000000350ef0\nCall Trace:\n <TASK>\n  tcp_recvmsg_locked+0x106d/0x25a0 net/ipv4/tcp.c:2513\n  tcp_recvmsg+0x25d/0x920 net/ipv4/tcp.c:2578\n  inet6_recvmsg+0x16a/0x730 net/ipv6/af_inet6.c:680\n  sock_recvmsg_nosec net/socket.c:1046 [inline]\n  sock_recvmsg+0x109/0x280 net/socket.c:1068\n  ____sys_recvmsg+0x1db/0x470 net/socket.c:2803\n  ___sys_recvmsg net/socket.c:2845 [inline]\n  do_recvmmsg+0x474/0xae0 net/socket.c:2939\n  __sys_recvmmsg net/socket.c:3018 [inline]\n  __do_sys_recvmmsg net/socket.c:3041 [inline]\n  __se_sys_recvmmsg net/socket.c:3034 [inline]\n  __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034\n  do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n  do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7faeb6363db9\nCode: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007ffcc1997168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b\nRAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007faeb6363db9\nRDX: 0000000000000001 RSI: 0000000020000bc0 RDI: 0000000000000005\nRBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000001c\nR10: 0000000000000122 R11: 0000000000000246 R12: 0000000000000000\nR13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001","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-369"],"references":["https://git.kernel.org/stable/c/2552c9d9440f8e7a2ed0660911ff00f25b90a0a4","https://git.kernel.org/stable/c/34e41a031fd7523bf1cd00a2adca2370aebea270","https://git.kernel.org/stable/c/3fe4ef0568a48369b1891395d13ac593b1ba41b1","https://git.kernel.org/stable/c/413c33b9f3bc36fdf719690a78824db9f88a9485","https://git.kernel.org/stable/c/94062790aedb505bdda209b10bea47b294d6394f"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:51:20.603330631+00:00"},"epss":{"cve":"CVE-2024-36905","score":0.00332,"percentile":0.26139,"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."]}