{"cve":"CVE-2024-26864","nvd":{"published":"2024-04-17T11:15:09.153","modified":"2026-08-04T11:17:14.467","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: Fix refcnt handling in __inet_hash_connect().\n\nsyzbot reported a warning in sk_nulls_del_node_init_rcu().\n\nThe commit 66b60b0c8c4a (\"dccp/tcp: Unhash sk from ehash for tb2 alloc\nfailure after check_estalblished().\") tried to fix an issue that an\nunconnected socket occupies an ehash entry when bhash2 allocation fails.\n\nIn such a case, we need to revert changes done by check_established(),\nwhich does not hold refcnt when inserting socket into ehash.\n\nSo, to revert the change, we need to __sk_nulls_add_node_rcu() instead\nof sk_nulls_add_node_rcu().\n\nOtherwise, sock_put() will cause refcnt underflow and leak the socket.\n\n[0]:\nWARNING: CPU: 0 PID: 23948 at include/net/sock.h:799 sk_nulls_del_node_init_rcu+0x166/0x1a0 include/net/sock.h:799\nModules linked in:\nCPU: 0 PID: 23948 Comm: syz-executor.2 Not tainted 6.8.0-rc6-syzkaller-00159-gc055fc00c07b #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024\nRIP: 0010:sk_nulls_del_node_init_rcu+0x166/0x1a0 include/net/sock.h:799\nCode: e8 7f 71 c6 f7 83 fb 02 7c 25 e8 35 6d c6 f7 4d 85 f6 0f 95 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 1b 6d c6 f7 90 <0f> 0b 90 eb b2 e8 10 6d c6 f7 4c 89 e7 be 04 00 00 00 e8 63 e7 d2\nRSP: 0018:ffffc900032d7848 EFLAGS: 00010246\nRAX: ffffffff89cd0035 RBX: 0000000000000001 RCX: 0000000000040000\nRDX: ffffc90004de1000 RSI: 000000000003ffff RDI: 0000000000040000\nRBP: 1ffff1100439ac26 R08: ffffffff89ccffe3 R09: 1ffff1100439ac28\nR10: dffffc0000000000 R11: ffffed100439ac29 R12: ffff888021cd6140\nR13: dffffc0000000000 R14: ffff88802a9bf5c0 R15: ffff888021cd6130\nFS:  00007f3b823f16c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f3b823f0ff8 CR3: 000000004674a000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n __inet_hash_connect+0x140f/0x20b0 net/ipv4/inet_hashtables.c:1139\n dccp_v6_connect+0xcb9/0x1480 net/dccp/ipv6.c:956\n __inet_stream_connect+0x262/0xf30 net/ipv4/af_inet.c:678\n inet_stream_connect+0x65/0xa0 net/ipv4/af_inet.c:749\n __sys_connect_file net/socket.c:2048 [inline]\n __sys_connect+0x2df/0x310 net/socket.c:2065\n __do_sys_connect net/socket.c:2075 [inline]\n __se_sys_connect net/socket.c:2072 [inline]\n __x64_sys_connect+0x7a/0x90 net/socket.c:2072\n do_syscall_64+0xf9/0x240\n entry_SYSCALL_64_after_hwframe+0x6f/0x77\nRIP: 0033:0x7f3b8167dda9\nCode: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007f3b823f10c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a\nRAX: ffffffffffffffda RBX: 00007f3b817abf80 RCX: 00007f3b8167dda9\nRDX: 000000000000001c RSI: 0000000020000040 RDI: 0000000000000003\nRBP: 00007f3b823f1120 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001\nR13: 000000000000000b R14: 00007f3b817abf80 R15: 00007ffd3beb57b8\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:H/I:H/A:H","score":7.8},"cwes":["CWE-200"],"references":["https://git.kernel.org/stable/c/04d9d1fc428ac9f581d55118d67e0cb546701feb","https://git.kernel.org/stable/c/1b20e61d36f490319d3fbdedd410155232ab5190","https://git.kernel.org/stable/c/856baaa100cd288d3685eedae9a129c996e7e755","https://git.kernel.org/stable/c/86d9b040421bbd26425f5a3edc226f57ecdecbfe","https://git.kernel.org/stable/c/ad105cde6b261b8b05ec872fe7d1987417d7fe5a"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:49:08.435428910+00:00"},"epss":{"cve":"CVE-2024-26864","score":0.00613,"percentile":0.49369,"date":"2026-10-31"},"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."]}