CVE-2025-21938 - Vulnerability Details

Link	Providers
https://git.kernel.org/stable/c/022bfe24aad8937705704ff2e414b100cf0f2e1a
https://git.kernel.org/stable/c/125ccafe6dd062901b5a0c31ee9038740fc8859e
https://git.kernel.org/stable/c/4b228dae3d2cc6d9dce167449cd8fa9f028e9376
https://git.kernel.org/stable/c/f1404f368c40fc6a068dad72e4ee0824ee6a78ee
https://git.kernel.org/stable/c/f3fcdb2de9fdbed9d8c6a8eb2c5fbd7d6f54a4d8
https://lore.kernel.org/linux-cve-announce/2025040134-CVE-2025-21938-3b75@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2025-21938
https://www.cve.org/CVERecord?id=CVE-2025-21938

Type	Values Removed	Values Added
Weaknesses		CWE-362
Metrics	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}`	cvssV3_1 `{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}`

Type	Values Removed	Values Added
References		https://lore.kernel.org/linux-cve-announce/2025040134-CVE-2025-21938-3b75@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2025-21938 https://www.cve.org/CVERecord?id=CVE-2025-21938
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Moderate`

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: mptcp: fix 'scheduling while atomic' in mptcp_pm_nl_append_new_local_addr If multiple connection requests attempt to create an implicit mptcp endpoint in parallel, more than one caller may end up in mptcp_pm_nl_append_new_local_addr because none found the address in local_addr_list during their call to mptcp_pm_nl_get_local_id. In this case, the concurrent new_local_addr calls may delete the address entry created by the previous caller. These deletes use synchronize_rcu, but this is not permitted in some of the contexts where this function may be called. During packet recv, the caller may be in a rcu read critical section and have preemption disabled. An example stack: BUG: scheduling while atomic: swapper/2/0/0x00000302 Call Trace: <IRQ> 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)) </IRQ> This problem seems particularly prevalent if the user advertises an endpoint that has a different external vs internal address. In the case where the external address is advertised and multiple connections already exist, multiple subflow SYNs arrive in parallel which tends to trigger the race during creation of the first local_addr_list entries which have the internal address instead. Fix by skipping the replacement of an existing implicit local address if called via mptcp_pm_nl_get_local_id.
Title		mptcp: fix 'scheduling while atomic' in mptcp_pm_nl_append_new_local_addr
References		https://git.kernel.org/stable/c/022bfe24aad8937705704ff2e414b100cf0f2e1a https://git.kernel.org/stable/c/125ccafe6dd062901b5a0c31ee9038740fc8859e https://git.kernel.org/stable/c/4b228dae3d2cc6d9dce167449cd8fa9f028e9376 https://git.kernel.org/stable/c/f1404f368c40fc6a068dad72e4ee0824ee6a78ee https://git.kernel.org/stable/c/f3fcdb2de9fdbed9d8c6a8eb2c5fbd7d6f54a4d8

Show plain JSON

{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2025-21938", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.789Z", "datePublished": "2025-04-01T15:41:04.886Z", "dateUpdated": "2025-05-04T07:25:04.321Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-05-04T07:25:04.321Z"}, "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."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/mptcp/pm_netlink.c"], "versions": [{"version": "d045b9eb95a9b611c483897a69e7285aefdc66d7", "lessThan": "f1404f368c40fc6a068dad72e4ee0824ee6a78ee", "status": "affected", "versionType": "git"}, {"version": "d045b9eb95a9b611c483897a69e7285aefdc66d7", "lessThan": "f3fcdb2de9fdbed9d8c6a8eb2c5fbd7d6f54a4d8", "status": "affected", "versionType": "git"}, {"version": "d045b9eb95a9b611c483897a69e7285aefdc66d7", "lessThan": "4b228dae3d2cc6d9dce167449cd8fa9f028e9376", "status": "affected", "versionType": "git"}, {"version": "d045b9eb95a9b611c483897a69e7285aefdc66d7", "lessThan": "125ccafe6dd062901b5a0c31ee9038740fc8859e", "status": "affected", "versionType": "git"}, {"version": "d045b9eb95a9b611c483897a69e7285aefdc66d7", "lessThan": "022bfe24aad8937705704ff2e414b100cf0f2e1a", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/mptcp/pm_netlink.c"], "versions": [{"version": "5.18", "status": "affected"}, {"version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.131", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.83", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.19", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.13.7", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.14", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.1.131"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.6.83"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.12.19"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.13.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.14"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/f1404f368c40fc6a068dad72e4ee0824ee6a78ee"}, {"url": "https://git.kernel.org/stable/c/f3fcdb2de9fdbed9d8c6a8eb2c5fbd7d6f54a4d8"}, {"url": "https://git.kernel.org/stable/c/4b228dae3d2cc6d9dce167449cd8fa9f028e9376"}, {"url": "https://git.kernel.org/stable/c/125ccafe6dd062901b5a0c31ee9038740fc8859e"}, {"url": "https://git.kernel.org/stable/c/022bfe24aad8937705704ff2e414b100cf0f2e1a"}], "title": "mptcp: fix 'scheduling while atomic' in mptcp_pm_nl_append_new_local_addr", "x_generator": {"engine": "bippy-1.2.0"}}}}

{

dataType : CVE_RECORD (string)

dataVersion : 5.1 (string)

cveMetadata : { »

cveId : CVE-2025-21938 (string)

assignerOrgId : 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (string)

state : PUBLISHED (string)

assignerShortName : Linux (string)

dateReserved : 2024-12-29T08:45:45.789Z (string)

datePublished : 2025-04-01T15:41:04.886Z (string)

dateUpdated : 2025-05-04T07:25:04.321Z (string)

}

containers : { »

cna : { »

providerMetadata : { »

orgId : 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (string)

shortName : Linux (string)

dateUpdated : 2025-05-04T07:25:04.321Z (string)

}

descriptions : [ »

0 : { »

lang : en (string)

value : In the Linux kernel, the following vulnerability has been resolved: mptcp: fix 'scheduling while atomic' in mptcp_pm_nl_append_new_local_addr If multiple connection requests attempt to create an implicit mptcp endpoint in parallel, more than one caller may end up in mptcp_pm_nl_append_new_local_addr because none found the address in local_addr_list during their call to mptcp_pm_nl_get_local_id. In this case, the concurrent new_local_addr calls may delete the address entry created by the previous caller. These deletes use synchronize_rcu, but this is not permitted in some of the contexts where this function may be called. During packet recv, the caller may be in a rcu read critical section and have preemption disabled. An example stack: BUG: scheduling while atomic: swapper/2/0/0x00000302 Call Trace: <IRQ> 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)) </IRQ> This problem seems particularly prevalent if the user advertises an endpoint that has a different external vs internal address. In the case where the external address is advertised and multiple connections already exist, multiple subflow SYNs arrive in parallel which tends to trigger the race during creation of the first local_addr_list entries which have the internal address instead. Fix by skipping the replacement of an existing implicit local address if called via mptcp_pm_nl_get_local_id. (string)

}

]

affected : [ »

0 : { »

product : Linux (string)

vendor : Linux (string)

defaultStatus : unaffected (string)

repo : https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git (string)

programFiles : [ »

0 : net/mptcp/pm_netlink.c (string)

]

versions : [ »

0 : { »

version : d045b9eb95a9b611c483897a69e7285aefdc66d7 (string)

lessThan : f1404f368c40fc6a068dad72e4ee0824ee6a78ee (string)

status : affected (string)

versionType : git (string)

}

1 : { »

version : d045b9eb95a9b611c483897a69e7285aefdc66d7 (string)

lessThan : f3fcdb2de9fdbed9d8c6a8eb2c5fbd7d6f54a4d8 (string)

status : affected (string)

versionType : git (string)

}

2 : { »

version : d045b9eb95a9b611c483897a69e7285aefdc66d7 (string)

lessThan : 4b228dae3d2cc6d9dce167449cd8fa9f028e9376 (string)

status : affected (string)

versionType : git (string)

}

3 : { »

version : d045b9eb95a9b611c483897a69e7285aefdc66d7 (string)

lessThan : 125ccafe6dd062901b5a0c31ee9038740fc8859e (string)

status : affected (string)

versionType : git (string)

}

4 : { »

version : d045b9eb95a9b611c483897a69e7285aefdc66d7 (string)

lessThan : 022bfe24aad8937705704ff2e414b100cf0f2e1a (string)

status : affected (string)

versionType : git (string)

}

]

}

1 : { »

product : Linux (string)

vendor : Linux (string)

defaultStatus : affected (string)

repo : https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git (string)

programFiles : [ »

0 : net/mptcp/pm_netlink.c (string)

]

versions : [ »

0 : { »

version : 5.18 (string)

status : affected (string)

}

1 : { »

version : 0 (string)

lessThan : 5.18 (string)

status : unaffected (string)

versionType : semver (string)

}

2 : { »

version : 6.1.131 (string)

lessThanOrEqual : 6.1.* (string)

status : unaffected (string)

versionType : semver (string)

}

3 : { »

version : 6.6.83 (string)

lessThanOrEqual : 6.6.* (string)

status : unaffected (string)

versionType : semver (string)

}

4 : { »

version : 6.12.19 (string)

lessThanOrEqual : 6.12.* (string)

status : unaffected (string)

versionType : semver (string)

}

5 : { »

version : 6.13.7 (string)

lessThanOrEqual : 6.13.* (string)

status : unaffected (string)

versionType : semver (string)

}

6 : { »

version : 6.14 (string)

lessThanOrEqual : * (string)

status : unaffected (string)

versionType : original_commit_for_fix (string)

}

]

}

]

cpeApplicability : [ »

0 : { »

nodes : [ »

0 : { »

operator : OR (string)

negate : false (boolean)

cpeMatch : [ »

0 : { »

vulnerable : true (boolean)

criteria : cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* (string)