{"id":"CVE-2023-54265","summary":"ipv6: Fix an uninit variable access bug in __ip6_make_skb()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: Fix an uninit variable access bug in __ip6_make_skb()\n\nSyzbot reported a bug as following:\n\n=====================================================\nBUG: KMSAN: uninit-value in arch_atomic64_inc arch/x86/include/asm/atomic64_64.h:88 [inline]\nBUG: KMSAN: uninit-value in arch_atomic_long_inc include/linux/atomic/atomic-long.h:161 [inline]\nBUG: KMSAN: uninit-value in atomic_long_inc include/linux/atomic/atomic-instrumented.h:1429 [inline]\nBUG: KMSAN: uninit-value in __ip6_make_skb+0x2f37/0x30f0 net/ipv6/ip6_output.c:1956\n arch_atomic64_inc arch/x86/include/asm/atomic64_64.h:88 [inline]\n arch_atomic_long_inc include/linux/atomic/atomic-long.h:161 [inline]\n atomic_long_inc include/linux/atomic/atomic-instrumented.h:1429 [inline]\n __ip6_make_skb+0x2f37/0x30f0 net/ipv6/ip6_output.c:1956\n ip6_finish_skb include/net/ipv6.h:1122 [inline]\n ip6_push_pending_frames+0x10e/0x550 net/ipv6/ip6_output.c:1987\n rawv6_push_pending_frames+0xb12/0xb90 net/ipv6/raw.c:579\n rawv6_sendmsg+0x297e/0x2e60 net/ipv6/raw.c:922\n inet_sendmsg+0x101/0x180 net/ipv4/af_inet.c:827\n sock_sendmsg_nosec net/socket.c:714 [inline]\n sock_sendmsg net/socket.c:734 [inline]\n ____sys_sendmsg+0xa8e/0xe70 net/socket.c:2476\n ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2530\n __sys_sendmsg net/socket.c:2559 [inline]\n __do_sys_sendmsg net/socket.c:2568 [inline]\n __se_sys_sendmsg net/socket.c:2566 [inline]\n __x64_sys_sendmsg+0x367/0x540 net/socket.c:2566\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nUninit was created at:\n slab_post_alloc_hook mm/slab.h:766 [inline]\n slab_alloc_node mm/slub.c:3452 [inline]\n __kmem_cache_alloc_node+0x71f/0xce0 mm/slub.c:3491\n __do_kmalloc_node mm/slab_common.c:967 [inline]\n __kmalloc_node_track_caller+0x114/0x3b0 mm/slab_common.c:988\n kmalloc_reserve net/core/skbuff.c:492 [inline]\n __alloc_skb+0x3af/0x8f0 net/core/skbuff.c:565\n alloc_skb include/linux/skbuff.h:1270 [inline]\n __ip6_append_data+0x51c1/0x6bb0 net/ipv6/ip6_output.c:1684\n ip6_append_data+0x411/0x580 net/ipv6/ip6_output.c:1854\n rawv6_sendmsg+0x2882/0x2e60 net/ipv6/raw.c:915\n inet_sendmsg+0x101/0x180 net/ipv4/af_inet.c:827\n sock_sendmsg_nosec net/socket.c:714 [inline]\n sock_sendmsg net/socket.c:734 [inline]\n ____sys_sendmsg+0xa8e/0xe70 net/socket.c:2476\n ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2530\n __sys_sendmsg net/socket.c:2559 [inline]\n __do_sys_sendmsg net/socket.c:2568 [inline]\n __se_sys_sendmsg net/socket.c:2566 [inline]\n __x64_sys_sendmsg+0x367/0x540 net/socket.c:2566\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nIt is because icmp6hdr does not in skb linear region under the scenario\nof SOCK_RAW socket. Access icmp6_hdr(skb)-\u003eicmp6_type directly will\ntrigger the uninit variable access bug.\n\nUse a local variable icmp6_type to carry the correct value in different\nscenarios.","modified":"2026-04-02T09:45:43.810624Z","published":"2025-12-30T12:15:57.557Z","related":["SUSE-SU-2026:0473-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/54xxx/CVE-2023-54265.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/02ed5700f40445af02d1c97db25ffc2d04971d9f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/0cf600ca1bdf1d52df977516ee6cee0cadb1f6b1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/165370522cc48127da564a08584a7391e6341908"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2c9cefc142c1dc2759e19a92d3b2b3715e985beb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/605b056d63302ae84eb136e88d4df49124bd5e0d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d65ff2fe877c471aa6e79efa7bd8ff66e147c317"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ea30388baebcce37fd594d425a65037ca35e59e8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f394f690a30a5ec0413c62777a058eaf3d6e10d5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/54xxx/CVE-2023-54265.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-54265"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"14878f75abd5bf1d38becb405801cd491ee215dc"},{"fixed":"165370522cc48127da564a08584a7391e6341908"},{"fixed":"f394f690a30a5ec0413c62777a058eaf3d6e10d5"},{"fixed":"0cf600ca1bdf1d52df977516ee6cee0cadb1f6b1"},{"fixed":"605b056d63302ae84eb136e88d4df49124bd5e0d"},{"fixed":"d65ff2fe877c471aa6e79efa7bd8ff66e147c317"},{"fixed":"2c9cefc142c1dc2759e19a92d3b2b3715e985beb"},{"fixed":"02ed5700f40445af02d1c97db25ffc2d04971d9f"},{"fixed":"ea30388baebcce37fd594d425a65037ca35e59e8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-54265.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.24"},{"fixed":"4.14.313"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"4.19.281"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.4.241"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.107"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.24"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.2.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-54265.json"}}],"schema_version":"1.7.5"}