CVE-2025-21938

{"id": "CVE-2025-21938", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.7, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.0}]}, "published": "2025-04-01T16:15:24.667", "references": [{"url": "https://git.kernel.org/stable/c/022bfe24aad8937705704ff2e414b100cf0f2e1a", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/125ccafe6dd062901b5a0c31ee9038740fc8859e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/4b228dae3d2cc6d9dce167449cd8fa9f028e9376", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f1404f368c40fc6a068dad72e4ee0824ee6a78ee", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f3fcdb2de9fdbed9d8c6a8eb2c5fbd7d6f54a4d8", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-362"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix 'scheduling while atomic' in mptcp_pm_nl_append_new_local_addr\n\nIf multiple connection requests attempt to create an implicit mptcp\nendpoint in parallel, more than one caller may end up in\nmptcp_pm_nl_append_new_local_addr because none found the address in\nlocal_addr_list during their call to mptcp_pm_nl_get_local_id. In this\ncase, the concurrent new_local_addr calls may delete the address entry\ncreated by the previous caller. These deletes use synchronize_rcu, but\nthis is not permitted in some of the contexts where this function may be\ncalled. During packet recv, the caller may be in a rcu read critical\nsection and have preemption disabled.\n\nAn example stack:\n\n BUG: scheduling while atomic: swapper/2/0/0x00000302\n\n Call Trace:\n <IRQ>\n dump_stack_lvl (lib/dump_stack.c:117 (discriminator 1))\n dump_stack (lib/dump_stack.c:124)\n __schedule_bug (kernel/sched/core.c:5943)\n schedule_debug.constprop.0 (arch/x86/include/asm/preempt.h:33 kernel/sched/core.c:5970)\n __schedule (arch/x86/include/asm/jump_label.h:27 include/linux/jump_label.h:207 kernel/sched/features.h:29 kernel/sched/core.c:6621)\n schedule (arch/x86/include/asm/preempt.h:84 kernel/sched/core.c:6804 kernel/sched/core.c:6818)\n schedule_timeout (kernel/time/timer.c:2160)\n wait_for_completion (kernel/sched/completion.c:96 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:148)\n __wait_rcu_gp (include/linux/rcupdate.h:311 kernel/rcu/update.c:444)\n synchronize_rcu (kernel/rcu/tree.c:3609)\n mptcp_pm_nl_append_new_local_addr (net/mptcp/pm_netlink.c:966 net/mptcp/pm_netlink.c:1061)\n mptcp_pm_nl_get_local_id (net/mptcp/pm_netlink.c:1164)\n mptcp_pm_get_local_id (net/mptcp/pm.c:420)\n subflow_check_req (net/mptcp/subflow.c:98 net/mptcp/subflow.c:213)\n subflow_v4_route_req (net/mptcp/subflow.c:305)\n tcp_conn_request (net/ipv4/tcp_input.c:7216)\n subflow_v4_conn_request (net/mptcp/subflow.c:651)\n tcp_rcv_state_process (net/ipv4/tcp_input.c:6709)\n tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1934)\n tcp_v4_rcv (net/ipv4/tcp_ipv4.c:2334)\n ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205 (discriminator 1))\n ip_local_deliver_finish (include/linux/rcupdate.h:813 net/ipv4/ip_input.c:234)\n ip_local_deliver (include/linux/netfilter.h:314 include/linux/netfilter.h:308 net/ipv4/ip_input.c:254)\n ip_sublist_rcv_finish (include/net/dst.h:461 net/ipv4/ip_input.c:580)\n ip_sublist_rcv (net/ipv4/ip_input.c:640)\n ip_list_rcv (net/ipv4/ip_input.c:675)\n __netif_receive_skb_list_core (net/core/dev.c:5583 net/core/dev.c:5631)\n netif_receive_skb_list_internal (net/core/dev.c:5685 net/core/dev.c:5774)\n napi_complete_done (include/linux/list.h:37 include/net/gro.h:449 include/net/gro.h:444 net/core/dev.c:6114)\n igb_poll (drivers/net/ethernet/intel/igb/igb_main.c:8244) igb\n __napi_poll (net/core/dev.c:6582)\n net_rx_action (net/core/dev.c:6653 net/core/dev.c:6787)\n handle_softirqs (kernel/softirq.c:553)\n __irq_exit_rcu (kernel/softirq.c:588 kernel/softirq.c:427 kernel/softirq.c:636)\n irq_exit_rcu (kernel/softirq.c:651)\n common_interrupt (arch/x86/kernel/irq.c:247 (discriminator 14))\n </IRQ>\n\nThis problem seems particularly prevalent if the user advertises an\nendpoint that has a different external vs internal address. In the case\nwhere the external address is advertised and multiple connections\nalready exist, multiple subflow SYNs arrive in parallel which tends to\ntrigger the race during creation of the first local_addr_list entries\nwhich have the internal address instead.\n\nFix by skipping the replacement of an existing implicit local address if\ncalled via mptcp_pm_nl_get_local_id."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mptcp: correcci\u00f3n de 'programaci\u00f3n mientras es at\u00f3mica' en mptcp_pm_nl_append_new_local_addr Si varias solicitudes de conexi\u00f3n intentan crear un endpoint mptcp impl\u00edcito en paralelo, m\u00e1s de un llamador puede terminar en mptcp_pm_nl_append_new_local_addr porque ninguno encontr\u00f3 la direcci\u00f3n en local_addr_list durante su llamada a mptcp_pm_nl_get_local_id. En este caso, las llamadas new_local_addr concurrentes pueden eliminar la entrada de direcci\u00f3n creada por el llamador anterior. Estas eliminaciones usan synchronize_rcu, pero esto no est\u00e1 permitido en algunos de los contextos donde se puede llamar a esta funci\u00f3n. Durante la recepci\u00f3n de paquetes, el llamador puede estar en una secci\u00f3n cr\u00edtica de lectura de rcu y tener la preempci\u00f3n deshabilitada. Una pila de ejemplo: ERROR: programaci\u00f3n mientras es at\u00f3mica: swapper/2/0/0x00000302 Seguimiento de llamadas: dump_stack_lvl (lib/dump_stack.c:117 (discriminator 1)) dump_stack (lib/dump_stack.c:124) __schedule_bug (kernel/sched/core.c:5943) schedule_debug.constprop.0 (arch/x86/include/asm/preempt.h:33 kernel/sched/core.c:5970) __schedule (arch/x86/include/asm/jump_label.h:27 include/linux/jump_label.h:207 kernel/sched/features.h:29 kernel/sched/core.c:6621) schedule (arch/x86/include/asm/preempt.h:84 kernel/sched/core.c:6804 kernel/sched/core.c:6818) schedule_timeout (kernel/time/timer.c:2160) wait_for_completion (kernel/sched/completion.c:96 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:148) __wait_rcu_gp (include/linux/rcupdate.h:311 kernel/rcu/update.c:444) synchronize_rcu (kernel/rcu/tree.c:3609) mptcp_pm_nl_append_new_local_addr (net/mptcp/pm_netlink.c:966 net/mptcp/pm_netlink.c:1061) mptcp_pm_nl_get_local_id (net/mptcp/pm_netlink.c:1164) mptcp_pm_get_local_id (net/mptcp/pm.c:420) subflow_check_req (net/mptcp/subflow.c:98 net/mptcp/subflow.c:213) subflow_v4_route_req (net/mptcp/subflow.c:305) tcp_conn_request (net/ipv4/tcp_input.c:7216) subflow_v4_conn_request (net/mptcp/subflow.c:651) tcp_rcv_state_process (net/ipv4/tcp_input.c:6709) tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1934) tcp_v4_rcv (net/ipv4/tcp_ipv4.c:2334) ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205 (discriminator 1)) ip_local_deliver_finish (include/linux/rcupdate.h:813 net/ipv4/ip_input.c:234) ip_local_deliver (include/linux/netfilter.h:314 include/linux/netfilter.h:308 net/ipv4/ip_input.c:254) ip_sublist_rcv_finish (include/net/dst.h:461 net/ipv4/ip_input.c:580) ip_sublist_rcv (net/ipv4/ip_input.c:640) ip_list_rcv (net/ipv4/ip_input.c:675) __netif_receive_skb_list_core (net/core/dev.c:5583 net/core/dev.c:5631) netif_receive_skb_list_internal (net/core/dev.c:5685 net/core/dev.c:5774) napi_complete_done (include/linux/list.h:37 include/net/gro.h:449 include/net/gro.h:444 net/core/dev.c:6114) igb_poll (drivers/net/ethernet/intel/igb/igb_main.c:8244) igb __napi_poll (net/core/dev.c:6582) net_rx_action (net/core/dev.c:6653 net/core/dev.c:6787) handle_softirqs (kernel/softirq.c:553) __irq_exit_rcu (kernel/softirq.c:588 kernel/softirq.c:427 kernel/softirq.c:636) irq_exit_rcu (kernel/softirq.c:651) common_interrupt (arch/x86/kernel/irq.c:247 (discriminator 14)) Este problema parece ser particularmente frecuente si el usuario anuncia un endpoint que tiene una direcci\u00f3n interna y externa diferente. Si se anuncia la direcci\u00f3n externa y ya existen varias conexiones, llegan varios SYN de subflujo en paralelo, lo que suele desencadenar la ejecuci\u00f3n durante la creaci\u00f3n de las primeras entradas de local_addr_list que contienen la direcci\u00f3n interna. Se soluciona omitiendo el reemplazo de una direcci\u00f3n local impl\u00edcita existente si se llama mediante mptcp_pm_nl_get_local_id."}], "lastModified": "2025-10-30T19:44:47.107", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AEDD8C7D-37B5-46B9-9940-C119E7E07D12", "versionEndExcluding": "6.1.131", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7D9F642F-6E05-4926-B0FE-62F95B7266BC", "versionEndExcluding": "6.6.83", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "32865E5C-8AE1-4D3D-A64D-299039694A88", "versionEndExcluding": "6.12.19", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "842F5A44-3E71-4546-B4FD-43B0ACE3F32B", "versionEndExcluding": "6.13.7", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "186716B6-2B66-4BD0-852E-D48E71C0C85F"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0D3E781C-403A-498F-9DA9-ECEE50F41E75"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "66619FB8-0AAF-4166-B2CF-67B24143261D"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D3D6550E-6679-4560-902D-AF52DCFE905B"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "45B90F6B-BEC7-4D4E-883A-9DBADE021750"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}