CVE-2025-40257
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: fix a race in mptcp_pm_del_add_timer() mptcp_pm_del_add_timer() can call sk_stop_timer_sync(sk, &entry->add_timer) while another might have free entry already, as reported by syzbot. Add RCU protection to fix this issue. Also change confusing add_timer variable with stop_timer boolean. syzbot report: BUG: KASAN: slab-use-after-free in __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616 Read of size 4 at addr ffff8880311e4150 by task kworker/1:1/44 CPU: 1 UID: 0 PID: 44 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events mptcp_worker Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616 sk_stop_timer_sync+0x1b/0x90 net/core/sock.c:3631 mptcp_pm_del_add_timer+0x283/0x310 net/mptcp/pm.c:362 mptcp_incoming_options+0x1357/0x1f60 net/mptcp/options.c:1174 tcp_data_queue+0xca/0x6450 net/ipv4/tcp_input.c:5361 tcp_rcv_established+0x1335/0x2670 net/ipv4/tcp_input.c:6441 tcp_v4_do_rcv+0x98b/0xbf0 net/ipv4/tcp_ipv4.c:1931 tcp_v4_rcv+0x252a/0x2dc0 net/ipv4/tcp_ipv4.c:2374 ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6079 [inline] __netif_receive_skb+0x143/0x380 net/core/dev.c:6192 process_backlog+0x31e/0x900 net/core/dev.c:6544 __napi_poll+0xb6/0x540 net/core/dev.c:7594 napi_poll net/core/dev.c:7657 [inline] net_rx_action+0x5f7/0xda0 net/core/dev.c:7784 handle_softirqs+0x22f/0x710 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] __local_bh_enable_ip+0x1a0/0x2e0 kernel/softirq.c:302 mptcp_pm_send_ack net/mptcp/pm.c:210 [inline] mptcp_pm_addr_send_ack+0x41f/0x500 net/mptcp/pm.c:-1 mptcp_pm_worker+0x174/0x320 net/mptcp/pm.c:1002 mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Allocated by task 44: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x1ef/0x6c0 mm/slub.c:5748 kmalloc_noprof include/linux/slab.h:957 [inline] mptcp_pm_alloc_anno_list+0x104/0x460 net/mptcp/pm.c:385 mptcp_pm_create_subflow_or_signal_addr+0xf9d/0x1360 net/mptcp/pm_kernel.c:355 mptcp_pm_nl_fully_established net/mptcp/pm_kernel.c:409 [inline] __mptcp_pm_kernel_worker+0x417/0x1ef0 net/mptcp/pm_kernel.c:1529 mptcp_pm_worker+0x1ee/0x320 net/mptcp/pm.c:1008 mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 6630: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object m ---truncated---
View original CVE JSON
{
"id": "CVE-2025-40257",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-12-04T16:16:19.503",
"lastModified": "2026-10-19T21:10:00.160",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix a race in mptcp_pm_del_add_timer()\n\nmptcp_pm_del_add_timer() can call sk_stop_timer_sync(sk, &entry->add_timer)\nwhile another might have free entry already, as reported by syzbot.\n\nAdd RCU protection to fix this issue.\n\nAlso change confusing add_timer variable with stop_timer boolean.\n\nsyzbot report:\n\nBUG: KASAN: slab-use-after-free in __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616\nRead of size 4 at addr ffff8880311e4150 by task kworker/1:1/44\n\nCPU: 1 UID: 0 PID: 44 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT_{RT,(full)}\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025\nWorkqueue: events mptcp_worker\nCall Trace:\n <TASK>\n dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xca/0x240 mm/kasan/report.c:482\n kasan_report+0x118/0x150 mm/kasan/report.c:595\n __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616\n sk_stop_timer_sync+0x1b/0x90 net/core/sock.c:3631\n mptcp_pm_del_add_timer+0x283/0x310 net/mptcp/pm.c:362\n mptcp_incoming_options+0x1357/0x1f60 net/mptcp/options.c:1174\n tcp_data_queue+0xca/0x6450 net/ipv4/tcp_input.c:5361\n tcp_rcv_established+0x1335/0x2670 net/ipv4/tcp_input.c:6441\n tcp_v4_do_rcv+0x98b/0xbf0 net/ipv4/tcp_ipv4.c:1931\n tcp_v4_rcv+0x252a/0x2dc0 net/ipv4/tcp_ipv4.c:2374\n ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:205\n ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239\n NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318\n NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318\n __netif_receive_skb_one_core net/core/dev.c:6079 [inline]\n __netif_receive_skb+0x143/0x380 net/core/dev.c:6192\n process_backlog+0x31e/0x900 net/core/dev.c:6544\n __napi_poll+0xb6/0x540 net/core/dev.c:7594\n napi_poll net/core/dev.c:7657 [inline]\n net_rx_action+0x5f7/0xda0 net/core/dev.c:7784\n handle_softirqs+0x22f/0x710 kernel/softirq.c:622\n __do_softirq kernel/softirq.c:656 [inline]\n __local_bh_enable_ip+0x1a0/0x2e0 kernel/softirq.c:302\n mptcp_pm_send_ack net/mptcp/pm.c:210 [inline]\n mptcp_pm_addr_send_ack+0x41f/0x500 net/mptcp/pm.c:-1\n mptcp_pm_worker+0x174/0x320 net/mptcp/pm.c:1002\n mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762\n process_one_work kernel/workqueue.c:3263 [inline]\n process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346\n worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427\n kthread+0x711/0x8a0 kernel/kthread.c:463\n ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n </TASK>\n\nAllocated by task 44:\n kasan_save_stack mm/kasan/common.c:56 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:77\n poison_kmalloc_redzone mm/kasan/common.c:400 [inline]\n __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417\n kasan_kmalloc include/linux/kasan.h:262 [inline]\n __kmalloc_cache_noprof+0x1ef/0x6c0 mm/slub.c:5748\n kmalloc_noprof include/linux/slab.h:957 [inline]\n mptcp_pm_alloc_anno_list+0x104/0x460 net/mptcp/pm.c:385\n mptcp_pm_create_subflow_or_signal_addr+0xf9d/0x1360 net/mptcp/pm_kernel.c:355\n mptcp_pm_nl_fully_established net/mptcp/pm_kernel.c:409 [inline]\n __mptcp_pm_kernel_worker+0x417/0x1ef0 net/mptcp/pm_kernel.c:1529\n mptcp_pm_worker+0x1ee/0x320 net/mptcp/pm.c:1008\n mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762\n process_one_work kernel/workqueue.c:3263 [inline]\n process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346\n worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427\n kthread+0x711/0x8a0 kernel/kthread.c:463\n ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n\nFreed by task 6630:\n kasan_save_stack mm/kasan/common.c:56 [inline]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:77\n __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587\n kasan_save_free_info mm/kasan/kasan.h:406 [inline]\n poison_slab_object m\n---truncated---"
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmptcp: corregir una condición de carrera en mptcp_pm_del_add_timer()\n\nmptcp_pm_del_add_timer() puede llamar a sk_stop_timer_sync(sk, &entry->add_timer) mientras que otro podría haber liberado la entrada ya, según lo informado por syzbot.\n\nAñadir protección RCU para solucionar este problema.\n\nTambién cambiar la variable confusa add_timer por el booleano stop_timer.\n\nInforme de syzbot:\n\nBUG: KASAN: slab-uso después de liberación en __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616\nLectura de tamaño 4 en la dirección ffff8880311e4150 por la tarea kworker/1:1/44\n\nCPU: 1 UID: 0 PID: 44 Comm: kworker/1:1 No contaminado syzkaller #0 PREEMPT_{RT,(full)}\nNombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025\nCola de trabajo: events mptcp_worker\nTraza de llamada:\n <TAREA>\n dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [en línea]\n print_report+0xca/0x240 mm/kasan/report.c:482\n kasan_report+0x118/0x150 mm/kasan/report.c:595\n __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616\n sk_stop_timer_sync+0x1b/0x90 net/core/sock.c:3631\n mptcp_pm_del_add_timer+0x283/0x310 net/mptcp/pm.c:362\n mptcp_incoming_options+0x1357/0x1f60 net/mptcp/options.c:1174\n tcp_data_queue+0xca/0x6450 net/ipv4/tcp_input.c:5361\n tcp_rcv_established+0x1335/0x2670 net/ipv4/tcp_input.c:6441\n tcp_v4_do_rcv+0x98b/0xbf0 net/ipv4/tcp_ipv4.c:1931\n tcp_v4_rcv+0x252a/0x2dc0 net/ipv4/tcp_ipv4.c:2374\n ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:205\n ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239\n NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318\n NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318\n __netif_receive_skb_one_core net/core/dev.c:6079 [en línea]\n __netif_receive_skb+0x143/0x380 net/core/dev.c:6192\n process_backlog+0x31e/0x900 net/core/dev.c:6544\n __napi_poll+0xb6/0x540 net/core/dev.c:7594\n napi_poll net/core/dev.c:7657 [en línea]\n net_rx_action+0x5f7/0xda0 net/core/dev.c:7784\n handle_softirqs+0x22f/0x710 kernel/softirq.c:622\n __do_softirq kernel/softirq.c:656 [en línea]\n __local_bh_enable_ip+0x1a0/0x2e0 kernel/softirq.c:302\n mptcp_pm_send_ack net/mptcp/pm.c:210 [en línea]\n mptcp_pm_addr_send_ack+0x41f/0x500 net/mptcp/pm.c:-1\n mptcp_pm_worker+0x174/0x320 net/mptcp/pm.c:1002\n mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762\n process_one_work kernel/workqueue.c:3263 [en línea]\n process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346\n worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427\n kthread+0x711/0x8a0 kernel/kthread.c:463\n ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n </TAREA>\n\nAsignado por la tarea 44:\n kasan_save_stack mm/kasan/common.c:56 [en línea]\n kasan_save_track+0x3e/0x80 mm/kasan/common.c:77\n poison_kmalloc_redzone mm/kasan/common.c:400 [en línea]\n __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417\n kasan_kmalloc include/linux/kasan.h:262 [en línea]\n __kmalloc_cache_noprof+0x1ef/0x6c0 mm/slub.c:5748\n kmalloc_noprof include/linux/slab.h:957 [en línea]\n mptcp_pm_alloc_anno_list+0x104/0x460 net/mptcp/pm.c:385\n mptcp_pm_create_subflow_or_signal_addr+0xf9d/0x1360 net/mptcp/pm_kernel.c:355\n mptcp_pm_nl_fully_established net/mptcp/pm_kernel.c:409 [en línea]\n __mptcp_pm_kernel_worker+0x417/0x1ef0 net/mptcp/pm_kernel.c:1529\n mptcp_pm_worker+0x1ee/0x320 net/mptcp/pm.c:1008\n mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762\n process_one_work kernel/workqueue.c:3263 [en línea]\n process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346\n worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427\n kthread+0x711/0x8a0 kernel/kthread.c:463\n ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n\nLiberado por la tarea 6630:\n kasan_save_stack --TRUNCADO--"
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/mptcp/pm.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "00cfd77b9063dcdf3628a7087faba60de85a9cc8",
"lessThan": "9be29f8e7ce4e147e56caac2c3a0ce3573cf9c17",
"versionType": "git",
"status": "affected"
},
{
"version": "00cfd77b9063dcdf3628a7087faba60de85a9cc8",
"lessThan": "e2d1ad207174a7cd7903dd27a00db4b2dfa6c64b",
"versionType": "git",
"status": "affected"
},
{
"version": "00cfd77b9063dcdf3628a7087faba60de85a9cc8",
"lessThan": "385ddc0f008f24d1e7d03be998b3a98a37bd29ff",
"versionType": "git",
"status": "affected"
},
{
"version": "00cfd77b9063dcdf3628a7087faba60de85a9cc8",
"lessThan": "c602cc344b4b8d41515fec3ffa98457ac963ee12",
"versionType": "git",
"status": "affected"
},
{
"version": "00cfd77b9063dcdf3628a7087faba60de85a9cc8",
"lessThan": "6d3275d4ca62e2c02e1b7e8cd32db59df91c14b7",
"versionType": "git",
"status": "affected"
},
{
"version": "00cfd77b9063dcdf3628a7087faba60de85a9cc8",
"lessThan": "bbbd75346c8e6490b19c2ba90f38ea66ccf352b2",
"versionType": "git",
"status": "affected"
},
{
"version": "00cfd77b9063dcdf3628a7087faba60de85a9cc8",
"lessThan": "426358d9be7ce3518966422f87b96f1bad27295f",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/mptcp/pm.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.10",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.10",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.247",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.197",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.159",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.118",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.60",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.17.10",
"lessThanOrEqual": "6.17.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"affectedData": [
{
"vendor": "Siemens",
"product": "RUGGEDCOM RST2428P",
"defaultStatus": "unknown",
"versions": [
{
"version": "0",
"lessThan": "V4.0",
"versionType": "custom",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/385ddc0f008f24d1e7d03be998b3a98a37bd29ff",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/426358d9be7ce3518966422f87b96f1bad27295f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6d3275d4ca62e2c02e1b7e8cd32db59df91c14b7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9be29f8e7ce4e147e56caac2c3a0ce3573cf9c17",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/bbbd75346c8e6490b19c2ba90f38ea66ccf352b2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c602cc344b4b8d41515fec3ffa98457ac963ee12",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e2d1ad207174a7cd7903dd27a00db4b2dfa6c64b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-253495.html",
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"
}
]
}