{"cve":"CVE-2023-54265","nvd":{"published":"2025-12-30T13:16:15.300","modified":"2026-06-17T06:47:07.257","status":"Deferred","description":"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)->icmp6_type directly will\ntrigger the uninit variable access bug.\n\nUse a local variable icmp6_type to carry the correct value in different\nscenarios.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/02ed5700f40445af02d1c97db25ffc2d04971d9f","https://git.kernel.org/stable/c/0cf600ca1bdf1d52df977516ee6cee0cadb1f6b1","https://git.kernel.org/stable/c/165370522cc48127da564a08584a7391e6341908","https://git.kernel.org/stable/c/2c9cefc142c1dc2759e19a92d3b2b3715e985beb","https://git.kernel.org/stable/c/605b056d63302ae84eb136e88d4df49124bd5e0d"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:18:08.089039631+00:00"},"epss":{"cve":"CVE-2023-54265","score":0.0021,"percentile":0.11218,"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."]}