# CVE-2026-74257: sockmap: Fix use-after-free in udp_bpf_recvmsg() CVE-2026-74257 is fixed in 35 products on 1 platform, first by DEBIAN-CVE-2026-74257, released August 15, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-74257 - Priority: High - CVSS: 7.8 (Important) - EPSS: 0.0013 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 15, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-74257 ## Description In the Linux kernel, the following vulnerability has been resolved: sockmap: Fix use-after-free in udp_bpf_recvmsg() syzbot reported use-after-free of struct sk_msg in sk_msg_recvmsg(). [0] sk_msg_recvmsg() peeks sk_msg from psock->ingress_msg under a lock, but its processing is lockless. Thus, sk_msg_recvmsg() must be serialised by callers, otherwise multiple threads could touch the same sk_msg. For example, TCP uses lock_sock(), and AF_UNIX uses unix_sk(sk)->iolock. Initially, udp_bpf_recvmsg() had used lock_sock(), but the cited commit removed it. Let's serialise sk_msg_recvmsg() with lock_sock() in udp_bpf_recvmsg(). Note that holding spin_lock_bh(&sk->sk_receive_queue.lock) is not an option due to copy_page_to_iter() in sk_msg_recvmsg(). [0]: BUG: KASAN: slab-use-after-free in sk_msg_recvmsg+0xb54/0xc30 net/core/skmsg.c:428 Read of size 4 at addr ffff88814cdcf000 by task syz.0.24/6020 CPU: 1 UID: 0 PID: 6020 Comm: syz.0.24 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 sk_msg_recvmsg+0xb54/0xc30 net/core/skmsg.c:428 udp_bpf_recvmsg+0x4bd/0xe00 net/ipv4/udp_bpf.c:84 inet_recvmsg+0x260/0x270 net/ipv4/af_inet.c:891 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x1a8/0x270 net/socket.c:1100 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2812 ___sys_recvmsg+0x215/0x590 net/socket.c:2854 do_recvmmsg+0x334/0x800 net/socket.c:2949 __sys_recvmmsg net/socket.c:3023 [inline] __do_sys_recvmmsg net/socket.c:3046 [inline] __se_sys_recvmmsg net/socket.c:3039 [inline] __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3039 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb319f9aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb31ad97028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fb31a216090 RCX: 00007fb319f9aeb9 RDX: 0000000000000001 RSI: 0000200000000400 RDI: 0000000000000004 RBP: 00007fb31a008c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000040000021 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb31a216128 R14: 00007fb31a216090 R15: 00007ffe21dd0a98 Allocated by task 6019: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] alloc_sk_msg net/core/skmsg.c:510 [inline] sk_psock_skb_ingress_self+0x60/0x350 net/core/skmsg.c:612 sk_psock_verdict_apply net/core/skmsg.c:1038 [inline] sk_psock_verdict_recv+0x7d9/0x8d0 net/core/skmsg.c:1236 udp_read_skb+0x73e/0x7e0 net/ipv4/udp.c:2045 sk_psock_verdict_data_ready+0x12d/0x550 net/core/skmsg.c:1257 __udp_enqueue_schedule_skb+0xc54/0x10b0 net/ipv4/udp.c:1789 __udp_queue_rcv_skb net/ipv4/udp.c:2346 [inline] udp_queue_rcv_one_skb+0xac5/0x19c0 net/ipv4/udp.c:2475 __udp4_lib_mcast_deliver+0xc06/0xcf0 net/ipv4/udp.c:2585 __udp4_lib_rcv+0x10f6/0x2620 net/ipv4/udp.c:2724 ip_protocol_deliver_rcu+0x282/0x440 net/ipv4/ip_input.c:207 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 dst_input include/net/dst.h:474 [inline] ip_sublist_rcv_finish+0x221/0x2a0 net/ipv4/ip_input.c:584 ip_list_rcv_finish net/ipv4/ip_inp ---truncated--- ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-64kb sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 | | Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-azure sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 | | Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-default sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24197-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24197-1.md) | Nov 7, 2026 | | Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.39.1.160000.2.25 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.84.1.150700.17.47.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-default-base sles 16.0 | 6.12.0-160000.39.1.160000.2.26 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 | | Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-docs sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 | | Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 | | Linux | kernel-livepatch-6.18.41-94.142 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel-livepatch-SLE15-SP7-RT_Update_21 sles 15.7 | 1-150700.1.3.1 | [SUSE-SU-2026:4640-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4640-1.md) | Nov 7, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_22 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 | | Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-source sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 | | Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-syms sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 | | Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.39.1 | [OPENSUSE-SU-2026:22091-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22091-1.md) | Nov 7, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.84.1 | [SUSE-SU-2026:4706-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4706-1.md) | Nov 7, 2026 | | Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.39.1 | [SUSE-SU-2026:24235-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24235-1.md) | Nov 7, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-74257](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74257.md) | Aug 15, 2026 | | Linux | linux Debian 14 | 7.1.5-1 | [DEBIAN-CVE-2026-74257](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74257.md) | Aug 15, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.41-94.142.amzn2023 | [ALAS2023-2026-2071](https://patchblox.com/security/data/fix/linux/alas2023-2026-2071.md) | Aug 31, 2026 | --- Data as of 2026-11-09T01:18:40Z UTC. 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