In the Linux kernel, the following vulnerability has been resolved:
mptcp: make fallback action and fallback decision atomic
Syzkaller reported the following splat:
WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 __mptcp_do_fallback net/mptcp/protocol.h:1223 [inline] WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_do_fallback net/mptcp/protocol.h:1244 [inline] WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 check_fully_established net/mptcp/options.c:982 [inline] WARNING: CPU: 1 PID: 7704 at net/mptcp/protocol.h:1223 mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153 Modules linked in: CPU: 1 UID: 0 PID: 7704 Comm: syz.3.1419 Not tainted 6.16.0-rc3-gbd5ce2324dba #20 PREEMPT(voluntary) Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:__mptcp_do_fallback net/mptcp/protocol.h:1223 [inline] RIP: 0010:mptcp_do_fallback net/mptcp/protocol.h:1244 [inline] RIP: 0010:check_fully_established net/mptcp/options.c:982 [inline] RIP: 0010:mptcp_incoming_options+0x21a8/0x2510 net/mptcp/options.c:1153 Code: 24 18 e8 bb 2a 00 fd e9 1b df ff ff e8 b1 21 0f 00 e8 ec 5f c4 fc 44 0f b7 ac 24 b0 00 00 00 e9 54 f1 ff ff e8 d9 5f c4 fc 90 <0f> 0b 90 e9 b8 f4 ff ff e8 8b 2a 00 fd e9 8d e6 ff ff e8 81 2a 00 RSP: 0018:ffff8880a3f08448 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880180a8000 RCX: ffffffff84afcf45 RDX: ffff888090223700 RSI: ffffffff84afdaa7 RDI: 0000000000000001 RBP: ffff888017955780 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880180a8910 R14: ffff8880a3e9d058 R15: 0000000000000000 FS: 00005555791b8500(0000) GS:ffff88811c495000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2800b7 CR3: 0000000058e44000 CR4: 0000000000350ef0 Call Trace: <IRQ> tcp_reset+0x26f/0x2b0 net/ipv4/tcp_input.c:4432 tcp_validate_incoming+0x1057/0x1b60 net/ipv4/tcp_input.c:5975 tcp_rcv_established+0x5b5/0x21f0 net/ipv4/tcp_input.c:6166 tcp_v4_do_rcv+0x5dc/0xa70 net/ipv4/tcp_ipv4.c:1925 tcp_v4_rcv+0x3473/0x44a0 net/ipv4/tcp_ipv4.c:2363 ip_protocol_deliver_rcu+0xba/0x480 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2f1/0x500 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:317 [inline] NF_HOOK include/linux/netfilter.h:311 [inline] ip_local_deliver+0x1be/0x560 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:469 [inline] ip_rcv_finish net/ipv4/ip_input.c:447 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] NF_HOOK include/linux/netfilter.h:311 [inline] ip_rcv+0x514/0x810 net/ipv4/ip_input.c:567 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5975 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6088 process_backlog+0x301/0x1360 net/core/dev.c:6440 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7453 napi_poll net/core/dev.c:7517 [inline] net_rx_action+0xb44/0x1010 net/core/dev.c:7644 handle_softirqs+0x1d0/0x770 kernel/softirq.c:579 do_softirq+0x3f/0x90 kernel/softirq.c:480 </IRQ> <TASK> __local_bh_enable_ip+0xed/0x110 kernel/softirq.c:407 local_bh_enable include/linux/bottom_half.h:33 [inline] inet_csk_listen_stop+0x2c5/0x1070 net/ipv4/inet_connection_sock.c:1524 mptcp_check_listen_stop.part.0+0x1cc/0x220 net/mptcp/protocol.c:2985 mptcp_check_listen_stop net/mptcp/mib.h:118 [inline] __mptcp_close+0x9b9/0xbd0 net/mptcp/protocol.c:3000 mptcp_close+0x2f/0x140 net/mptcp/protocol.c:3066 inet_release+0xed/0x200 net/ipv4/af_inet.c:435 inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:487 __sock_release+0xb3/0x270 net/socket.c:649 sock_close+0x1c/0x30 net/socket.c:1439 __fput+0x402/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xd4 ---truncated---
CVSS Details
- CVSS 3.1 Base Score: 8.2
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade kernel6.12-tools-debuginfoUpgrade bpftool6.12-debuginfoUpgrade kernel-modules-extra-commonUpgrade perf6.12-debuginfoUpgrade bpftool-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-toolsUpgrade perfUpgrade kernel6.12-libbpf-debuginfoUpgrade perf-debuginfoUpgrade kernel-develUpgrade kernel6.12-libbpf-develUpgrade kernel6.12-develUpgrade bpftoolUpgrade python3-perf-debuginfoUpgrade kernel-libbpf-debuginfoUpgrade kernel-libbpf-develUpgrade kernel-modules-extraUpgrade kernel-livepatch-6.12.40-63.114Upgrade kernelUpgrade kernel-tools-debuginfoUpgrade kernel-debuginfo-common-x86_64Upgrade kernel6.12-libbpf-staticUpgrade bpftool6.12Upgrade python3-perfUpgrade python3-perf6.12Upgrade kernel6.12-debuginfoUpgrade kernel-livepatch-6.1.150-174.273Upgrade kernel6.12-debuginfo-common-x86_64Upgrade kernel-libbpf-staticUpgrade kernel6.12Upgrade kernel-debuginfoUpgrade kernel6.12-tools-develUpgrade kernel6.12-toolsUpgrade python3-perf6.12-debuginfoUpgrade kernel6.12-libbpfUpgrade kernel-libbpfUpgrade perf6.12Upgrade kernel6.12-headersUpgrade kernel-tools-develUpgrade kernel6.12-modules-extraUpgrade kernel6.12-debuginfo-common-aarch64Upgrade kernel-headersUpgrade kernel6.12-modules-extra-common | Sep 16, 2025 | Jul 28, 2025 |
| Debian | — | Upgrade linuxUpgrade linux-6.1 | Jul 31, 2025 | Jul 31, 2025 |
| Redhat_linux | — | No solution exists | Jul 31, 2025 | Jul 28, 2025 |
| Suse | — | Upgrade kernel-symsUpgrade kernel-syms-azureUpgrade dtb-mediatekUpgrade kernel-devel-azureUpgrade dtb-armUpgrade dtb-xilinxUpgrade gfs2-kmp-64kbUpgrade dtb-socionextUpgrade kernel-rt-develUpgrade kernel-azure-develUpgrade kernel-syms-rtUpgrade ocfs2-kmp-rtUpgrade cluster-md-kmp-defaultUpgrade kselftests-kmp-rtUpgrade dlm-kmp-azureUpgrade kselftests-kmp-defaultUpgrade dtb-amdUpgrade dtb-hisiliconUpgrade dtb-apmUpgrade kernel-debugUpgrade kernel-obs-qaUpgrade kernel-64kb-optionalUpgrade dlm-kmp-defaultUpgrade kernel-rt-livepatchUpgrade kernel-rt-livepatch-develUpgrade reiserfs-kmp-azureUpgrade dtb-rockchipUpgrade dtb-amlogicUpgrade kernel-debug-develUpgrade cluster-md-kmp-azureUpgrade kernel-defaultUpgrade kernel-docsUpgrade reiserfs-kmp-rtUpgrade kernel-kvmsmall-develUpgrade kernel-macrosUpgrade kernel-devel-rtUpgrade kernel-64kb-develUpgrade kernel-rt_debug-vdsoUpgrade kernel-azure-vdsoUpgrade kernel-default-extraUpgrade gfs2-kmp-rtUpgrade kernel-default-optionalUpgrade kernel-kvmsmallUpgrade kernel-rtUpgrade kernel-zfcpdumpUpgrade dtb-freescaleUpgrade kernel-rt-vdsoUpgrade kernel-default-base-rebuildUpgrade cluster-md-kmp-64kbUpgrade kernel-64kbUpgrade dtb-nvidiaUpgrade dtb-lgUpgrade kernel-default-vdsoUpgrade gfs2-kmp-defaultUpgrade dlm-kmp-rtUpgrade reiserfs-kmp-64kbUpgrade kernel-rt-extraUpgrade reiserfs-kmp-defaultUpgrade kernel-source-vanillaUpgrade dtb-marvellUpgrade dtb-allwinnerUpgrade kernel-kvmsmall-vdsoUpgrade kernel-azureUpgrade dtb-exynosUpgrade kernel-azure-optionalUpgrade cluster-md-kmp-rtUpgrade kernel-source-azureUpgrade kernel-64kb-extraUpgrade gfs2-kmp-azureUpgrade dtb-alteraUpgrade ocfs2-kmp-azureUpgrade ocfs2-kmp-64kbUpgrade kernel-rt_debugUpgrade kernel-rt-optionalUpgrade kernel-default-livepatch-develUpgrade dtb-broadcomUpgrade dlm-kmp-64kbUpgrade kernel-default-develUpgrade kernel-default-baseUpgrade kernel-azure-extraUpgrade dtb-sprdUpgrade kselftests-kmp-64kbUpgrade kernel-rt_debug-develUpgrade kernel-obs-buildUpgrade dtb-amazonUpgrade kselftests-kmp-azureUpgrade kernel-docs-htmlUpgrade dtb-qcomUpgrade dtb-renesasUpgrade ocfs2-kmp-defaultUpgrade dtb-caviumUpgrade dtb-appleUpgrade kernel-source-rtUpgrade kernel-sourceUpgrade kernel-develUpgrade kernel-default-livepatchUpgrade kernel-debug-vdso | Dec 5, 2025 | Sep 18, 2025 |
| Ubuntu | — | Upgrade linux-image-fips-6.8Upgrade linux-image-virtual-6.14Upgrade linux-image-xilinxUpgrade linux-image-6.8.0-1023-xilinxUpgrade linux-image-generic-6.14Upgrade linux-image-6.14.0-1018-raspiUpgrade linux-image-6.14.0-1017-oracle-64kUpgrade linux-image-6.8.0-1046-azure-fipsUpgrade linux-image-nvidia-6.8Upgrade linux-image-azureUpgrade linux-image-realtime-hwe-22.04Upgrade linux-image-6.8.0-1046-nvidia-lowlatency-64kUpgrade linux-image-gcpUpgrade linux-image-oracle-64k-6.14Upgrade linux-image-aws-64k-6.8Upgrade linux-image-gcp-6.14Upgrade linux-image-aws-64kUpgrade linux-image-gcp-fips-6.8Upgrade linux-image-gke-64k-6.8Upgrade linux-image-gke-64kUpgrade linux-image-oem-22.04bUpgrade linux-image-oem-24.04Upgrade linux-image-genericUpgrade linux-image-oem-24.04aUpgrade linux-image-gcp-64kUpgrade linux-image-aws-lts-24.04Upgrade linux-image-6.8.0-100-lowlatencyUpgrade linux-image-oracle-64kUpgrade linux-image-gkeopUpgrade linux-image-6.14.0-1020-gcp-64kUpgrade linux-image-6.14.0-1017-azureUpgrade linux-image-oracle-6.8Upgrade linux-image-generic-hwe-24.04Upgrade linux-image-oem-22.04dUpgrade linux-image-oracle-64k-lts-24.04Upgrade linux-image-realtime-hwe-24.04Upgrade linux-image-intel-iot-realtimeUpgrade linux-image-oracle-64k-6.8Upgrade linux-image-generic-6.8Upgrade linux-image-raspi-6.14Upgrade linux-image-gcp-64k-6.8Upgrade linux-image-raspi-6.8Upgrade linux-image-generic-hwe-22.04Upgrade linux-image-azure-6.8Upgrade linux-image-6.14.0-1016-oemUpgrade linux-image-gcp-fipsUpgrade linux-image-realtime-6.14Upgrade linux-image-virtual-6.8Upgrade linux-image-lowlatency-64k-hwe-22.04Upgrade linux-image-oem-22.04cUpgrade linux-image-6.8.0-1047-raspiUpgrade linux-image-aws-6.8Upgrade linux-image-6.8.0-1047-gcp-fipsUpgrade linux-image-aws-64k-6.14Upgrade linux-image-6.8.0-100-genericUpgrade linux-image-6.8.0-1043-oracleUpgrade linux-image-6.8.0-1046-aws-fipsUpgrade linux-image-gke-6.8Upgrade linux-image-gcp-lts-24.04Upgrade linux-image-xilinx-6.8Upgrade linux-image-nvidiaUpgrade linux-image-raspiUpgrade linux-image-kvmUpgrade linux-image-6.14.0-36-genericUpgrade linux-image-azure-fips-6.8Upgrade linux-image-6.14.0-1017-awsUpgrade linux-image-6.8.0-1044-ibmUpgrade linux-image-6.14.0-1017-oracleUpgrade linux-image-aws-6.14Upgrade linux-image-ibm-lts-24.04Upgrade linux-image-raspi-realtimeUpgrade linux-image-realtime-6.8.1Upgrade linux-image-aws-fips-6.8Upgrade linux-image-6.8.0-1043-gkeUpgrade linux-image-virtual-hwe-22.04Upgrade linux-image-generic-64kUpgrade linux-image-nvidia-64kUpgrade linux-image-6.8.0-1046-awsUpgrade linux-image-gcp-64k-6.14Upgrade linux-image-intel-iotgUpgrade linux-image-6.8.0-1043-oracle-64kUpgrade linux-image-6.8.0-1047-gcp-64kUpgrade linux-image-awsUpgrade linux-image-gcp-64k-lts-24.04Upgrade linux-image-6.8.0-1051-azureUpgrade linux-image-aws-fipsUpgrade linux-image-oracleUpgrade linux-image-generic-64k-6.14Upgrade linux-image-generic-lpaeUpgrade linux-image-lowlatency-64k-6.8Upgrade linux-image-generic-64k-6.8Upgrade linux-image-gkeUpgrade linux-image-6.8.0-1030-gkeopUpgrade linux-image-lowlatency-64kUpgrade linux-image-6.8.0-100-fipsUpgrade linux-image-lowlatency-hwe-22.04Upgrade linux-image-6.8.0-100-generic-64kUpgrade linux-image-6.8.0-1046-azureUpgrade linux-image-6.14.0-36-generic-64kUpgrade linux-image-virtual-hwe-24.04Upgrade linux-image-6.8.0-100-lowlatency-64kUpgrade linux-image-oem-6.14Upgrade linux-image-nvidia-hwe-22.04Upgrade linux-image-nvidia-64k-hwe-22.04Upgrade linux-image-azure-fipsUpgrade linux-image-6.8.0-1046-nvidia-64kUpgrade linux-image-realtimeUpgrade linux-image-6.8.1-1041-realtimeUpgrade linux-image-6.8.0-1043-gke-64kUpgrade linux-image-virtualUpgrade linux-image-nvidia-lowlatency-64kUpgrade linux-image-ibm-6.8Upgrade linux-image-azure-lts-24.04Upgrade linux-image-aws-64k-lts-24.04Upgrade linux-image-generic-64k-hwe-22.04Upgrade linux-image-azure-6.14Upgrade linux-image-6.8.0-1047-gcpUpgrade linux-image-6.14.0-1017-aws-64kUpgrade linux-image-oracle-6.14Upgrade linux-image-lowlatencyUpgrade linux-image-6.8.0-1046-nvidiaUpgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-6.8.0-1046-aws-64kUpgrade linux-image-nvidia-lowlatency-64k-6.8Upgrade linux-image-oem-22.04aUpgrade linux-image-6.8.0-2037-raspi-realtimeUpgrade linux-image-nvidia-lowlatency-6.8Upgrade linux-image-lowlatency-6.8Upgrade linux-image-fipsUpgrade linux-image-gcp-6.8Upgrade linux-image-ibmUpgrade linux-image-gkeop-6.8Upgrade linux-image-6.14.0-1020-gcpUpgrade linux-image-xilinx-zynqmpUpgrade linux-image-oracle-lts-24.04Upgrade linux-image-nvidia-lowlatencyUpgrade linux-image-ibm-classicUpgrade linux-image-6.8.0-1046-nvidia-lowlatencyUpgrade linux-image-nvidia-64k-6.8Upgrade linux-image-6.14.0-1016-realtimeUpgrade linux-image-raspi-realtime-6.8Upgrade linux-image-oem-22.04 | Jul 31, 2025 | Jul 28, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Jul 27, 2026 | Jul 28, 2025 |
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