{ "affected": [ { "ranges": [ { "events": [ { "introduced": "80c9abaabf4283f7cf4a0b3597cd302506635b7f" }, { "fixed": "58e82fc3dedb57b1432292504415b224fd2d6acb" }, { "fixed": "01b9115b55018123ef2449ac4951f89147a8428e" }, { "fixed": "3f63d1752d90c0e28be931a48ab5d89bc97d637d" }, { "fixed": "273c06b81d2e902b21acc801ae18c8276c8a9b69" }, { "fixed": "6de2a650917bedaaefd65b17cede83c5e2c1dedd" }, { "fixed": "e8417353cbd078d10531ba3928e609c84ab09e6b" }, { "fixed": "cea34abc94b0a81e3a8b5cfb41cf45af37c2c67e" }, { "fixed": "d129c3177d7b1138fd5066fcc63a698b3ba415b0" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" } ] }, { "package": { "ecosystem": "Linux", "name": "Kernel" }, "ranges": [ { "events": [ { "introduced": "2.6.21" }, { "fixed": "5.10.261" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.11.0" }, { "fixed": "5.15.212" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.16.0" }, { "fixed": "6.1.178" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.2.0" }, { "fixed": "6.6.145" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.7.0" }, { "fixed": "6.12.96" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.13.0" }, { "fixed": "6.18.39" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.19.0" }, { "fixed": "7.1.4" } ], "type": "ECOSYSTEM" } ] } ], "database_specific": { "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64436.json" }, "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: af_key: initialize alg_key_len for IPComp states\n\npfkey_msg2xfrm_state() handles the IPComp (SADB_X_SATYPE_IPCOMP) case by\nallocating x-\u003ecalg and copying only the algorithm name:\n\n\tx-\u003ecalg = kmalloc_obj(*x-\u003ecalg);\n\tif (!x-\u003ecalg) {\n\t\terr = -ENOMEM;\n\t\tgoto out;\n\t}\n\tstrcpy(x-\u003ecalg-\u003ealg_name, a-\u003ename);\n\tx-\u003eprops.calgo = sa-\u003esadb_sa_encrypt;\n\nUnlike the authentication (x-\u003eaalg) and encryption (x-\u003eealg) branches of\nthe same function, the compression branch never initializes\ncalg-\u003ealg_key_len. IPComp carries no key and the allocation only\nreserves sizeof(struct xfrm_algo) (i.e. no room for a key), so the field\nis left containing uninitialized slab data.\n\ncalg-\u003ealg_key_len is later used as a length by xfrm_algo_clone() when an\nIPComp state is cloned during XFRM_MSG_MIGRATE:\n\n\txfrm_state_migrate()\n\t xfrm_state_clone_and_setup()\n\t x-\u003ecalg = xfrm_algo_clone(orig-\u003ecalg);\n\t kmemdup(orig, xfrm_alg_len(orig));\n\nwhere xfrm_alg_len() returns sizeof(*alg) + (alg_key_len + 7) / 8. With\na non-zero garbage alg_key_len, kmemdup() reads past the end of the\n68-byte calg object. Adding an IPComp SA via PF_KEY and then migrating\nit triggers (net-next, KASAN, init_on_alloc=0):\n\n BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x44/0x60\n Read of size 4164 at addr ff11000025a74980 by task diag2/9287\n CPU: 3 UID: 0 PID: 9287 Comm: diag2 7.1.0-rc6-g903db046d557 #1\n Call Trace:\n \u003cTASK\u003e\n dump_stack_lvl+0x10e/0x1f0\n print_report+0xf7/0x600\n kasan_report+0xe4/0x120\n kasan_check_range+0x105/0x1b0\n __asan_memcpy+0x23/0x60\n kmemdup_noprof+0x44/0x60\n xfrm_state_migrate+0x70a/0x1da0\n xfrm_migrate+0x753/0x18a0\n xfrm_do_migrate+0xb47/0xf10\n xfrm_user_rcv_msg+0x411/0xb50\n netlink_rcv_skb+0x158/0x420\n xfrm_netlink_rcv+0x71/0x90\n netlink_unicast+0x584/0x850\n netlink_sendmsg+0x8b0/0xdc0\n ____sys_sendmsg+0x9f7/0xb90\n ___sys_sendmsg+0x134/0x1d0\n __sys_sendmsg+0x16d/0x220\n do_syscall_64+0x116/0x7d0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n \u003c/TASK\u003e\n\n Allocated by task 9287:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n __kasan_kmalloc+0xaa/0xb0\n pfkey_add+0x2652/0x2ea0\n pfkey_process+0x6d0/0x830\n pfkey_sendmsg+0x42c/0x850\n __sys_sendto+0x461/0x4b0\n __x64_sys_sendto+0xe0/0x1c0\n do_syscall_64+0x116/0x7d0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n The buggy address belongs to the object at ff11000025a74980\n which belongs to the cache kmalloc-96 of size 96\n The buggy address is located 0 bytes inside of\n allocated 68-byte region [ff11000025a74980, ff11000025a749c4)\n\nDepending on the uninitialized value the same field can instead request\nan oversized kmemdup() allocation and make the migration clone fail.\n\nThe XFRM netlink path is not affected: verify_one_alg() rejects an\nXFRMA_ALG_COMP attribute shorter than xfrm_alg_len(), so a calg added via\nXFRM_MSG_NEWSA is always self-consistent.\n\nInitialize calg-\u003ealg_key_len to 0, matching the aalg/ealg branches.", "id": "CVE-2026-64436", "modified": "2026-08-18T03:31:22.370053358Z", "published": "2026-07-25T08:51:10.370Z", "references": [ { "type": "WEB", "url": "https://git.kernel.org/stable/c/01b9115b55018123ef2449ac4951f89147a8428e" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/273c06b81d2e902b21acc801ae18c8276c8a9b69" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/3f63d1752d90c0e28be931a48ab5d89bc97d637d" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/58e82fc3dedb57b1432292504415b224fd2d6acb" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/6de2a650917bedaaefd65b17cede83c5e2c1dedd" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/cea34abc94b0a81e3a8b5cfb41cf45af37c2c67e" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/d129c3177d7b1138fd5066fcc63a698b3ba415b0" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/e8417353cbd078d10531ba3928e609c84ab09e6b" }, { "type": "ADVISORY", "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64436.json" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64436" }, { "type": "PACKAGE", "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git" } ], "schema_version": "1.9.0", "severity": [ { "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "type": "CVSS_V3" } ], "summary": "net: af_key: initialize alg_key_len for IPComp states" }