{"id":"CVE-2023-54265","state":"PUBLISHED","title":"ipv6: Fix an uninit variable access bug in __ip6_make_skb()","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.","publishedAt":"2025-12-30T12:15:57.557Z","updatedAt":"2026-05-11T19:58:37.830Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"165370522cc48127da564a08584a7391e6341908","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"f394f690a30a5ec0413c62777a058eaf3d6e10d5","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"0cf600ca1bdf1d52df977516ee6cee0cadb1f6b1","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"605b056d63302ae84eb136e88d4df49124bd5e0d","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"d65ff2fe877c471aa6e79efa7bd8ff66e147c317","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"2c9cefc142c1dc2759e19a92d3b2b3715e985beb","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"02ed5700f40445af02d1c97db25ffc2d04971d9f","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"ea30388baebcce37fd594d425a65037ca35e59e8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_output.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.24","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.24","versionType":"semver"},{"version":"4.14.313","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.281","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.241","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.178","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.107","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.24","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.11","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_output.c"]}],"references":["https://git.kernel.org/stable/c/165370522cc48127da564a08584a7391e6341908","https://git.kernel.org/stable/c/f394f690a30a5ec0413c62777a058eaf3d6e10d5","https://git.kernel.org/stable/c/0cf600ca1bdf1d52df977516ee6cee0cadb1f6b1","https://git.kernel.org/stable/c/605b056d63302ae84eb136e88d4df49124bd5e0d","https://git.kernel.org/stable/c/d65ff2fe877c471aa6e79efa7bd8ff66e147c317","https://git.kernel.org/stable/c/2c9cefc142c1dc2759e19a92d3b2b3715e985beb","https://git.kernel.org/stable/c/02ed5700f40445af02d1c97db25ffc2d04971d9f","https://git.kernel.org/stable/c/ea30388baebcce37fd594d425a65037ca35e59e8"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:42.242Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/54xxx/CVE-2023-54265.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-54265","state":"PUBLISHED","datePublished":"2025-12-30T12:15:57.557Z","dateUpdated":"2026-05-11T19:58:37.830Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-12-30T12:06:44.517Z"},"containers":{"cna":{"title":"ipv6: Fix an uninit variable access bug in __ip6_make_skb()","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"165370522cc48127da564a08584a7391e6341908","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"f394f690a30a5ec0413c62777a058eaf3d6e10d5","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"0cf600ca1bdf1d52df977516ee6cee0cadb1f6b1","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"605b056d63302ae84eb136e88d4df49124bd5e0d","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"d65ff2fe877c471aa6e79efa7bd8ff66e147c317","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"2c9cefc142c1dc2759e19a92d3b2b3715e985beb","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"02ed5700f40445af02d1c97db25ffc2d04971d9f","versionType":"git"},{"version":"14878f75abd5bf1d38becb405801cd491ee215dc","status":"affected","lessThan":"ea30388baebcce37fd594d425a65037ca35e59e8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_output.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.24","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.24","versionType":"semver"},{"version":"4.14.313","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.281","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.241","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.178","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.107","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.24","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.11","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ip6_output.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/165370522cc48127da564a08584a7391e6341908"},{"url":"https://git.kernel.org/stable/c/f394f690a30a5ec0413c62777a058eaf3d6e10d5"},{"url":"https://git.kernel.org/stable/c/0cf600ca1bdf1d52df977516ee6cee0cadb1f6b1"},{"url":"https://git.kernel.org/stable/c/605b056d63302ae84eb136e88d4df49124bd5e0d"},{"url":"https://git.kernel.org/stable/c/d65ff2fe877c471aa6e79efa7bd8ff66e147c317"},{"url":"https://git.kernel.org/stable/c/2c9cefc142c1dc2759e19a92d3b2b3715e985beb"},{"url":"https://git.kernel.org/stable/c/02ed5700f40445af02d1c97db25ffc2d04971d9f"},{"url":"https://git.kernel.org/stable/c/ea30388baebcce37fd594d425a65037ca35e59e8"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T19:58:37.830Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"4.14.313"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"4.19.281"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"5.4.241"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"5.10.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"5.15.107"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"6.1.24"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"6.2.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.24","versionEndExcluding":"6.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}