CVE-2026-43167

{"id": "CVE-2026-43167", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-43167", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-11-06T15:30:10.397460Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "d77e38e612a017480157fe6d2c1422f42cb5b7e3", "lessThan": "d4df5a7da376e35089b8b601a86ff8a4cf997e2f", "versionType": "git"}, {"status": "affected", "version": "d77e38e612a017480157fe6d2c1422f42cb5b7e3", "lessThan": "166801e49a5b5fc127b8c9e2f110f303cfddfbc3", "versionType": "git"}, {"status": "affected", "version": "d77e38e612a017480157fe6d2c1422f42cb5b7e3", "lessThan": "a3c8fede034fa27892f87c863cbd5493167d17ed", "versionType": "git"}, {"status": "affected", "version": "d77e38e612a017480157fe6d2c1422f42cb5b7e3", "lessThan": "59581778792cbaf8ad788f4a21dc663ce986050e", "versionType": "git"}, {"status": "affected", "version": "d77e38e612a017480157fe6d2c1422f42cb5b7e3", "lessThan": "8c75c455ecd3bfd2f36abf66edb7021c4fa19ec4", "versionType": "git"}, {"status": "affected", "version": "d77e38e612a017480157fe6d2c1422f42cb5b7e3", "lessThan": "4efa91a28576054aae0e6dad9cba8fed8293aef8", "versionType": "git"}], "programFiles": ["net/xfrm/xfrm_device.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.12"}, {"status": "unaffected", "version": "0", "lessThan": "4.12", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.191", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.128", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.75", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.16", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "6.19.6", "versionType": "semver", "lessThanOrEqual": "6.19.*"}, {"status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/xfrm/xfrm_device.c"], "defaultStatus": "affected"}]}], "published": "2026-05-06T12:16:34.913", "references": [{"url": "https://git.kernel.org/stable/c/166801e49a5b5fc127b8c9e2f110f303cfddfbc3", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/4efa91a28576054aae0e6dad9cba8fed8293aef8", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/59581778792cbaf8ad788f4a21dc663ce986050e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8c75c455ecd3bfd2f36abf66edb7021c4fa19ec4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a3c8fede034fa27892f87c863cbd5493167d17ed", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d4df5a7da376e35089b8b601a86ff8a4cf997e2f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: always flush state and policy upon NETDEV_UNREGISTER event\n\nsyzbot is reporting that \"struct xfrm_state\" refcount is leaking.\n\n unregister_netdevice: waiting for netdevsim0 to become free. Usage count = 2\n ref_tracker: netdev@ffff888052f24618 has 1/1 users at\n __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline]\n netdev_tracker_alloc include/linux/netdevice.h:4412 [inline]\n xfrm_dev_state_add+0x3a5/0x1080 net/xfrm/xfrm_device.c:316\n xfrm_state_construct net/xfrm/xfrm_user.c:986 [inline]\n xfrm_add_sa+0x34ff/0x5fa0 net/xfrm/xfrm_user.c:1022\n xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3507\n netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550\n xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3529\n netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]\n netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344\n netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894\n sock_sendmsg_nosec net/socket.c:727 [inline]\n __sock_sendmsg net/socket.c:742 [inline]\n ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592\n ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646\n __sys_sendmsg+0x16d/0x220 net/socket.c:2678\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nThis is because commit d77e38e612a0 (\"xfrm: Add an IPsec hardware\noffloading API\") implemented xfrm_dev_unregister() as no-op despite\nxfrm_dev_state_add() from xfrm_state_construct() acquires a reference\nto \"struct net_device\".\nI guess that that commit expected that NETDEV_DOWN event is fired before\nNETDEV_UNREGISTER event fires, and also assumed that xfrm_dev_state_add()\nis called only if (dev->features & NETIF_F_HW_ESP) != 0.\n\nSabrina Dubroca identified steps to reproduce the same symptoms as below.\n\n echo 0 > /sys/bus/netdevsim/new_device\n dev=$(ls -1 /sys/bus/netdevsim/devices/netdevsim0/net/)\n ip xfrm state add src 192.168.13.1 dst 192.168.13.2 proto esp \\\n spi 0x1000 mode tunnel aead 'rfc4106(gcm(aes))' $key 128 \\\n offload crypto dev $dev dir out\n ethtool -K $dev esp-hw-offload off\n echo 0 > /sys/bus/netdevsim/del_device\n\nLike these steps indicate, the NETIF_F_HW_ESP bit can be cleared after\nxfrm_dev_state_add() acquired a reference to \"struct net_device\".\nAlso, xfrm_dev_state_add() does not check for the NETIF_F_HW_ESP bit\nwhen acquiring a reference to \"struct net_device\".\n\nCommit 03891f820c21 (\"xfrm: handle NETDEV_UNREGISTER for xfrm device\")\nre-introduced the NETDEV_UNREGISTER event to xfrm_dev_event(), but that\ncommit for unknown reason chose to share xfrm_dev_down() between the\nNETDEV_DOWN event and the NETDEV_UNREGISTER event.\nI guess that that commit missed the behavior in the previous paragraph.\n\nTherefore, we need to re-introduce xfrm_dev_unregister() in order to\nrelease the reference to \"struct net_device\" by unconditionally flushing\nstate and policy."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nxfrm: siempre vaciar el estado y la pol\u00edtica al evento NETDEV_UNREGISTER\n\nsyzbot est\u00e1 informando que el contador de referencias de \u2019struct xfrm_state\u2019 tiene una fuga.\n\n unregister_netdevice: waiting for netdevsim0 to become free. Usage count = 2\n ref_tracker: netdev@ffff888052f24618 has 1/1 users at\n __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline]\n netdev_tracker_alloc include/linux/netdevice.h:4412 [inline]\n xfrm_dev_state_add+0x3a5/0x 1080 net/xfrm/xfrm_device.c:316\n xfrm_state_construct net/xfrm/xfrm_user.c:986 [inline]\n xfrm_add_sa+0x 34ff/0x 5fa0 net/xfrm/xfrm_user.c:1022\n xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3507\n netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550\n xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3529\n netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]\n netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344\n netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894\n sock_sendmsg_nosec net/socket.c:727 [inline]\n __sock_sendmsg net/socket.c:742 [inline]\n ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592\n ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646\n __sys_sendmsg+0x16d/0x220 net/socket.c:2678\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nEsto se debe a que el commit d77e38e612a0 (\u2019xfrm: A\u00f1adir una API de descarga de hardware IPsec\u2019) implement\u00f3 xfrm_dev_unregister() como una no-op a pesar de que xfrm_dev_state_add() de xfrm_state_construct() adquiere una referencia a \u2019struct net_device\u2019.\nSupongo que ese commit esperaba que el evento NETDEV_DOWN se disparara antes de que se disparara el evento NETDEV_UNREGISTER, y tambi\u00e9n asumi\u00f3 que xfrm_dev_state_add() se llama solo si (dev -> features & NETIF_F_HW_ESP) != 0.\n\nSabrina Dubroca identific\u00f3 los pasos para reproducir los mismos s\u00edntomas que se indican a continuaci\u00f3n.\n\n echo 0 > /sys/bus/netdevsim/new_device\n dev=$(ls -1 /sys/bus/netdevsim/devices/netdevsim0/net/)\n ip xfrm state add src 192.168.13.1 dst 192.168.13.2 proto esp \\\n spi 0x 1000 mode tunnel aead \u2019rfc4106(gcm(aes))\u2019 $key 128 \\\n offload crypto dev $dev dir out\n ethtool -K $dev esp-hw-offload off\n echo 0 > /sys/bus/netdevsim/del_device\n\nComo indican estos pasos, el bit NETIF_F_HW_ESP puede ser borrado despu\u00e9s de que xfrm_dev_state_add() adquiriera una referencia a \u2019struct net_device\u2019.\nAdem\u00e1s, xfrm_dev_state_add() no comprueba el bit NETIF_F_HW_ESP al adquirir una referencia a \u2019struct net_device\u2019.\n\nEl commit 03891f820c21 (\u2019xfrm: manejar NETDEV_UNREGISTER para dispositivo xfrm\u2019) reintrodujo el evento NETDEV_UNREGISTER en xfrm_dev_event(), pero ese commit, por razones desconocidas, eligi\u00f3 compartir xfrm_dev_down() entre el evento NETDEV_DOWN y el evento NETDEV_UNREGISTER.\nSupongo que ese commit pas\u00f3 por alto el comportamiento del p\u00e1rrafo anterior.\n\nPor lo tanto, necesitamos reintroducir xfrm_dev_unregister() para liberar la referencia a \u2019struct net_device\u2019 vaciando incondicionalmente el estado y la pol\u00edtica."}], "lastModified": "2026-11-11T20:10:00.273", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E90AEF03-C864-4508-AA5A-71B005F9732D", "versionEndExcluding": "6.6.128", "versionStartIncluding": "4.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2", "versionEndExcluding": "6.12.75", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B", "versionEndExcluding": "6.18.16", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67", "versionEndExcluding": "6.19.6", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}