CVE-2026-68138

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-68138", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.370Z", "datePublished": "2026-08-10T11:59:01.744Z", "dateUpdated": "2026-10-19T20:58:52.975Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:45:55.796Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: serialize qdisc_rtab_list against concurrent get/put\n\nqdisc_get_rtab() and qdisc_put_rtab() mutate the process-global singly\nlinked list qdisc_rtab_list and a plain non-atomic 'int refcnt' with no\nlock. This was only safe because every caller historically held the RTNL\nmutex, which serialized all rate-table lookups, inserts and frees.\n\nThat invariant no longer holds. cls_flower sets\nTCF_PROTO_OPS_DOIT_UNLOCKED, so tc_new_tfilter() keeps rtnl_held == false\nfor it and sets TCA_ACT_FLAGS_NO_RTNL. That flag propagates through\ntcf_exts_validate_ex() -> tcf_action_init() -> tcf_action_init_1() ->\ntcf_police_init(), which calls qdisc_get_rtab()/qdisc_put_rtab() with the\nRTNL mutex NOT held. Two RTM_NEWTFILTER requests on different CPUs, each\nadding a flower filter with a police action carrying the same rate, then\nrace on qdisc_rtab_list and on the non-atomic refcnt, leading to a\nuse-after-free / double-free of the kmalloc-2k struct qdisc_rate_table.\nqdisc_rtab_list is a single global (not per-netns), so the corrupted\nobject is shared system-wide.\n\n BUG: KASAN: slab-use-after-free in qdisc_put_rtab+0x12f/0x160\n qdisc_put_rtab+0x12f/0x160\n tcf_police_init+0xda9/0x1590\n tcf_action_init_1+0x460/0x6b0\n tcf_action_init+0x439/0xa40\n tcf_exts_validate_ex+0x42d/0x550\n fl_change+0xddd/0x7da0\n tc_new_tfilter+0xaa7/0x2420\n rtnetlink_rcv_msg+0x95e/0xe90\n which belongs to the cache kmalloc-2k of size 2048\n\nProtect qdisc_rtab_list and the refcount with a dedicated spinlock. The\n(sleeping, GFP_KERNEL) allocation in qdisc_get_rtab() is performed before\ntaking the lock; if a concurrent inserter added an identical table in the\nmeantime the freshly allocated one is freed under the lock, so no\nduplicate is leaked. qdisc_put_rtab() now decrements the refcount and\nunlinks under the same lock."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is reached only via local RTM_NEWTFILTER rtnetlink messages (tc flower filter with police action) through rtnetlink_rcv_msg\u2192tc_new_tfilter\u2192fl_change\u2192tcf_police_init\u2192qdisc_get_rtab/qdisc_put_rtab; no remote packet or network protocol path exists.\nAC:L - cls_flower is TCF_PROTO_OPS_DOIT_UNLOCKED, so concurrent RTM_NEWTFILTER requests run without RTNL; the attacker controls both racing threads/CPUs and can repeatedly install flower filters with identical police rate tables to deterministically hit the global qdisc_rtab_list/refcnt race.\nPR:L - Non-GET rtnetlink handlers require netlink_net_capable(CAP_NET_ADMIN); this is namespace-scoped, so an unprivileged local user obtains CAP_NET_ADMIN via user namespaces (unshare -Urn), sets up clsact/ingress, and installs flower+police rules without init-namespace root.\nUI:N - Exploitation is fully self-contained: the attacker issues the concurrent tc/netlink commands from its own processes and needs no victim to mount filesystems, click links, or perform any other interactive action.\nS:U - Impact is heap corruption and UAF/double-free in kernel kmalloc-2k slabs within the same kernel security authority; although qdisc_rtab_list is global across netns, this is standard kernel memory corruption/privilege escalation, not a VM, IOMMU, or sandbox boundary escape.\nC:H - Concurrent non-atomic refcnt and list updates cause slab use-after-free/double-free of struct qdisc_rate_table (KASAN-confirmed in qdisc_put_rtab); freed 2KB objects are attacker-influenceable via kmalloc timing and are classically weaponizable for arbitrary kernel memory disclosure.\nI:H - The race corrupts a process-global singly linked list and can double-free a kmalloc-2k qdisc_rate_table, yielding classic heap metadata/object corruption primitives that can be developed into arbitrary kernel writes and local privilege escalation/code execution.\nA:H - Demonstrated KASAN slab-use-after-free in qdisc_put_rtab on the error/teardown path, and concurrent double-free of the same rate table can panic the kernel; the trigger is repeatable at will with concurrent netlink requests and causes task death or system-wide instability."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/sched/sch_api.c"], "versions": [{"version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "1b050d09dd1a0ddae83bf012cf4956b7a960235f", "status": "affected", "versionType": "git"}, {"version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "6e0241f6cbb149d926ee8efee2c734fea71452cf", "status": "affected", "versionType": "git"}, {"version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "f93c89392bd3b180b5b7abc6fdae8e3dd667a313", "status": "affected", "versionType": "git"}, {"version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "4131dd0b6f67acddd616ed7c244e1d3eedd46e7b", "status": "affected", "versionType": "git"}, {"version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "d981098b76756ed71666a27518eeb69883657c43", "status": "affected", "versionType": "git"}, {"version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "8ddc2eb0d2da9c83f54f1e5720525b461b8480c4", "status": "affected", "versionType": "git"}, {"version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "fb29e1b41052488ee3f2d115d4a870497ebd7f7d", "status": "affected", "versionType": "git"}, {"version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "f43ee0c0730d6191629b5ee1ceae27b1ebfdc047", "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/sched/sch_api.c"], "versions": [{"version": "5.1", "status": "affected"}, {"version": "0", "lessThan": "5.1", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.266", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.217", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.153", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.105", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.46", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "5.1", "versionEndExcluding": "5.10.266"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "5.15.217"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.1.184"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.6.153"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.12.105"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.18.46"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.1.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1b050d09dd1a0ddae83bf012cf4956b7a960235f"}, {"url": "https://git.kernel.org/stable/c/6e0241f6cbb149d926ee8efee2c734fea71452cf"}, {"url": "https://git.kernel.org/stable/c/f93c89392bd3b180b5b7abc6fdae8e3dd667a313"}, {"url": "https://git.kernel.org/stable/c/4131dd0b6f67acddd616ed7c244e1d3eedd46e7b"}, {"url": "https://git.kernel.org/stable/c/d981098b76756ed71666a27518eeb69883657c43"}, {"url": "https://git.kernel.org/stable/c/8ddc2eb0d2da9c83f54f1e5720525b461b8480c4"}, {"url": "https://git.kernel.org/stable/c/fb29e1b41052488ee3f2d115d4a870497ebd7f7d"}, {"url": "https://git.kernel.org/stable/c/f43ee0c0730d6191629b5ee1ceae27b1ebfdc047"}], "title": "net/sched: serialize qdisc_rtab_list against concurrent get/put", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-68138", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:44:32.003419Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-362", "description": "CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T20:58:52.975Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-68138", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:44:32.003419Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-362", "description": "CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:44:32.799Z"}}], "cna": {"title": "net/sched: serialize qdisc_rtab_list against concurrent get/put", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 7.8, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is reached only via local RTM_NEWTFILTER rtnetlink messages (tc flower filter with police action) through rtnetlink_rcv_msg\u2192tc_new_tfilter\u2192fl_change\u2192tcf_police_init\u2192qdisc_get_rtab/qdisc_put_rtab; no remote packet or network protocol path exists.\nAC:L - cls_flower is TCF_PROTO_OPS_DOIT_UNLOCKED, so concurrent RTM_NEWTFILTER requests run without RTNL; the attacker controls both racing threads/CPUs and can repeatedly install flower filters with identical police rate tables to deterministically hit the global qdisc_rtab_list/refcnt race.\nPR:L - Non-GET rtnetlink handlers require netlink_net_capable(CAP_NET_ADMIN); this is namespace-scoped, so an unprivileged local user obtains CAP_NET_ADMIN via user namespaces (unshare -Urn), sets up clsact/ingress, and installs flower+police rules without init-namespace root.\nUI:N - Exploitation is fully self-contained: the attacker issues the concurrent tc/netlink commands from its own processes and needs no victim to mount filesystems, click links, or perform any other interactive action.\nS:U - Impact is heap corruption and UAF/double-free in kernel kmalloc-2k slabs within the same kernel security authority; although qdisc_rtab_list is global across netns, this is standard kernel memory corruption/privilege escalation, not a VM, IOMMU, or sandbox boundary escape.\nC:H - Concurrent non-atomic refcnt and list updates cause slab use-after-free/double-free of struct qdisc_rate_table (KASAN-confirmed in qdisc_put_rtab); freed 2KB objects are attacker-influenceable via kmalloc timing and are classically weaponizable for arbitrary kernel memory disclosure.\nI:H - The race corrupts a process-global singly linked list and can double-free a kmalloc-2k qdisc_rate_table, yielding classic heap metadata/object corruption primitives that can be developed into arbitrary kernel writes and local privilege escalation/code execution.\nA:H - Demonstrated KASAN slab-use-after-free in qdisc_put_rtab on the error/teardown path, and concurrent double-free of the same rate table can panic the kernel; the trigger is repeatable at will with concurrent netlink requests and causes task death or system-wide instability."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "1b050d09dd1a0ddae83bf012cf4956b7a960235f", "versionType": "git"}, {"status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "6e0241f6cbb149d926ee8efee2c734fea71452cf", "versionType": "git"}, {"status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "f93c89392bd3b180b5b7abc6fdae8e3dd667a313", "versionType": "git"}, {"status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "4131dd0b6f67acddd616ed7c244e1d3eedd46e7b", "versionType": "git"}, {"status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "d981098b76756ed71666a27518eeb69883657c43", "versionType": "git"}, {"status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "8ddc2eb0d2da9c83f54f1e5720525b461b8480c4", "versionType": "git"}, {"status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "fb29e1b41052488ee3f2d115d4a870497ebd7f7d", "versionType": "git"}, {"status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "lessThan": "f43ee0c0730d6191629b5ee1ceae27b1ebfdc047", "versionType": "git"}], "programFiles": ["net/sched/sch_api.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.1"}, {"status": "unaffected", "version": "0", "lessThan": "5.1", "versionType": "semver"}, {"status": "unaffected", "version": "5.10.266", "versionType": "semver", "lessThanOrEqual": "5.10.*"}, {"status": "unaffected", "version": "5.15.217", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.184", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.153", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.105", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.46", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.6", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/sched/sch_api.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/1b050d09dd1a0ddae83bf012cf4956b7a960235f"}, {"url": "https://git.kernel.org/stable/c/6e0241f6cbb149d926ee8efee2c734fea71452cf"}, {"url": "https://git.kernel.org/stable/c/f93c89392bd3b180b5b7abc6fdae8e3dd667a313"}, {"url": "https://git.kernel.org/stable/c/4131dd0b6f67acddd616ed7c244e1d3eedd46e7b"}, {"url": "https://git.kernel.org/stable/c/d981098b76756ed71666a27518eeb69883657c43"}, {"url": "https://git.kernel.org/stable/c/8ddc2eb0d2da9c83f54f1e5720525b461b8480c4"}, {"url": "https://git.kernel.org/stable/c/fb29e1b41052488ee3f2d115d4a870497ebd7f7d"}, {"url": "https://git.kernel.org/stable/c/f43ee0c0730d6191629b5ee1ceae27b1ebfdc047"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: serialize qdisc_rtab_list against concurrent get/put\n\nqdisc_get_rtab() and qdisc_put_rtab() mutate the process-global singly\nlinked list qdisc_rtab_list and a plain non-atomic 'int refcnt' with no\nlock. This was only safe because every caller historically held the RTNL\nmutex, which serialized all rate-table lookups, inserts and frees.\n\nThat invariant no longer holds. cls_flower sets\nTCF_PROTO_OPS_DOIT_UNLOCKED, so tc_new_tfilter() keeps rtnl_held == false\nfor it and sets TCA_ACT_FLAGS_NO_RTNL. That flag propagates through\ntcf_exts_validate_ex() -> tcf_action_init() -> tcf_action_init_1() ->\ntcf_police_init(), which calls qdisc_get_rtab()/qdisc_put_rtab() with the\nRTNL mutex NOT held. Two RTM_NEWTFILTER requests on different CPUs, each\nadding a flower filter with a police action carrying the same rate, then\nrace on qdisc_rtab_list and on the non-atomic refcnt, leading to a\nuse-after-free / double-free of the kmalloc-2k struct qdisc_rate_table.\nqdisc_rtab_list is a single global (not per-netns), so the corrupted\nobject is shared system-wide.\n\n BUG: KASAN: slab-use-after-free in qdisc_put_rtab+0x12f/0x160\n qdisc_put_rtab+0x12f/0x160\n tcf_police_init+0xda9/0x1590\n tcf_action_init_1+0x460/0x6b0\n tcf_action_init+0x439/0xa40\n tcf_exts_validate_ex+0x42d/0x550\n fl_change+0xddd/0x7da0\n tc_new_tfilter+0xaa7/0x2420\n rtnetlink_rcv_msg+0x95e/0xe90\n which belongs to the cache kmalloc-2k of size 2048\n\nProtect qdisc_rtab_list and the refcount with a dedicated spinlock. The\n(sleeping, GFP_KERNEL) allocation in qdisc_get_rtab() is performed before\ntaking the lock; if a concurrent inserter added an identical table in the\nmeantime the freshly allocated one is freed under the lock, so no\nduplicate is leaked. qdisc_put_rtab() now decrements the refcount and\nunlinks under the same lock."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.10.266", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.217", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.184", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.153", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.105", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.46", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.6", "versionStartIncluding": "5.1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "5.1"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:45:55.796Z"}}}, "cveMetadata": {"cveId": "CVE-2026-68138", "state": "PUBLISHED", "dateUpdated": "2026-10-19T20:58:52.975Z", "dateReserved": "2026-07-30T09:28:09.370Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-10T11:59:01.744Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/sched/sch_api.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "1b050d09dd1a0ddae83bf012cf4956b7a960235f", "status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "versionType": "git"}, {"lessThan": "6e0241f6cbb149d926ee8efee2c734fea71452cf", "status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "versionType": "git"}, {"lessThan": "f93c89392bd3b180b5b7abc6fdae8e3dd667a313", "status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "versionType": "git"}, {"lessThan": "4131dd0b6f67acddd616ed7c244e1d3eedd46e7b", "status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "versionType": "git"}, {"lessThan": "d981098b76756ed71666a27518eeb69883657c43", "status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "versionType": "git"}, {"lessThan": "8ddc2eb0d2da9c83f54f1e5720525b461b8480c4", "status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "versionType": "git"}, {"lessThan": "fb29e1b41052488ee3f2d115d4a870497ebd7f7d", "status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "versionType": "git"}, {"lessThan": "f43ee0c0730d6191629b5ee1ceae27b1ebfdc047", "status": "affected", "version": "470502de5bdb1ed0def643a4458593a40b8f6b66", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/sched/sch_api.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.1"}, {"lessThan": "5.1", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.266", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.217", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.184", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.153", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.105", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.46", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.6", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: serialize qdisc_rtab_list against concurrent get/put\n\nqdisc_get_rtab() and qdisc_put_rtab() mutate the process-global singly\nlinked list qdisc_rtab_list and a plain non-atomic 'int refcnt' with no\nlock. This was only safe because every caller historically held the RTNL\nmutex, which serialized all rate-table lookups, inserts and frees.\n\nThat invariant no longer holds. cls_flower sets\nTCF_PROTO_OPS_DOIT_UNLOCKED, so tc_new_tfilter() keeps rtnl_held == false\nfor it and sets TCA_ACT_FLAGS_NO_RTNL. That flag propagates through\ntcf_exts_validate_ex() -> tcf_action_init() -> tcf_action_init_1() ->\ntcf_police_init(), which calls qdisc_get_rtab()/qdisc_put_rtab() with the\nRTNL mutex NOT held. Two RTM_NEWTFILTER requests on different CPUs, each\nadding a flower filter with a police action carrying the same rate, then\nrace on qdisc_rtab_list and on the non-atomic refcnt, leading to a\nuse-after-free / double-free of the kmalloc-2k struct qdisc_rate_table.\nqdisc_rtab_list is a single global (not per-netns), so the corrupted\nobject is shared system-wide.\n\n BUG: KASAN: slab-use-after-free in qdisc_put_rtab+0x12f/0x160\n qdisc_put_rtab+0x12f/0x160\n tcf_police_init+0xda9/0x1590\n tcf_action_init_1+0x460/0x6b0\n tcf_action_init+0x439/0xa40\n tcf_exts_validate_ex+0x42d/0x550\n fl_change+0xddd/0x7da0\n tc_new_tfilter+0xaa7/0x2420\n rtnetlink_rcv_msg+0x95e/0xe90\n which belongs to the cache kmalloc-2k of size 2048\n\nProtect qdisc_rtab_list and the refcount with a dedicated spinlock. The\n(sleeping, GFP_KERNEL) allocation in qdisc_get_rtab() is performed before\ntaking the lock; if a concurrent inserter added an identical table in the\nmeantime the freshly allocated one is freed under the lock, so no\nduplicate is leaked. qdisc_put_rtab() now decrements the refcount and\nunlinks under the same lock."}], "id": "CVE-2026-68138", "lastModified": "2026-10-19T21:17:53.507", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-68138", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T15:44:32.003419Z", "version": "2.0.3"}}]}, "published": "2026-08-10T13:19:59.410", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1b050d09dd1a0ddae83bf012cf4956b7a960235f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4131dd0b6f67acddd616ed7c244e1d3eedd46e7b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6e0241f6cbb149d926ee8efee2c734fea71452cf"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8ddc2eb0d2da9c83f54f1e5720525b461b8480c4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d981098b76756ed71666a27518eeb69883657c43"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f43ee0c0730d6191629b5ee1ceae27b1ebfdc047"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f93c89392bd3b180b5b7abc6fdae8e3dd667a313"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fb29e1b41052488ee3f2d115d4a870497ebd7f7d"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-362"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: Linux kernel: Denial of Service due to race condition in networking scheduler", "id": "2513343", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2513343"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.1", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-364", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet/sched: serialize qdisc_rtab_list against concurrent get/put\nqdisc_get_rtab() and qdisc_put_rtab() mutate the process-global singly\nlinked list qdisc_rtab_list and a plain non-atomic 'int refcnt' with no\nlock. This was only safe because every caller historically held the RTNL\nmutex, which serialized all rate-table lookups, inserts and frees.\nThat invariant no longer holds. cls_flower sets\nTCF_PROTO_OPS_DOIT_UNLOCKED, so tc_new_tfilter() keeps rtnl_held == false\nfor it and sets TCA_ACT_FLAGS_NO_RTNL. That flag propagates through\ntcf_exts_validate_ex() -> tcf_action_init() -> tcf_action_init_1() ->\ntcf_police_init(), which calls qdisc_get_rtab()/qdisc_put_rtab() with the\nRTNL mutex NOT held. Two RTM_NEWTFILTER requests on different CPUs, each\nadding a flower filter with a police action carrying the same rate, then\nrace on qdisc_rtab_list and on the non-atomic refcnt, leading to a\nuse-after-free / double-free of the kmalloc-2k struct qdisc_rate_table.\nqdisc_rtab_list is a single global (not per-netns), so the corrupted\nobject is shared system-wide.\nBUG: KASAN: slab-use-after-free in qdisc_put_rtab+0x12f/0x160\nqdisc_put_rtab+0x12f/0x160\ntcf_police_init+0xda9/0x1590\ntcf_action_init_1+0x460/0x6b0\ntcf_action_init+0x439/0xa40\ntcf_exts_validate_ex+0x42d/0x550\nfl_change+0xddd/0x7da0\ntc_new_tfilter+0xaa7/0x2420\nrtnetlink_rcv_msg+0x95e/0xe90\nwhich belongs to the cache kmalloc-2k of size 2048\nProtect qdisc_rtab_list and the refcount with a dedicated spinlock. The\n(sleeping, GFP_KERNEL) allocation in qdisc_get_rtab() is performed before\ntaking the lock; if a concurrent inserter added an identical table in the\nmeantime the freshly allocated one is freed under the lock, so no\nduplicate is leaked. qdisc_put_rtab() now decrements the refcount and\nunlinks under the same lock.", "A flaw was found in the Linux kernel's networking scheduler component. A race condition exists in the handling of rate tables (`qdisc_rtab_list`) due to a lack of proper locking during concurrent operations. A local attacker could exploit this by sending specially crafted network filter requests, leading to a use-after-free or double-free vulnerability. This could result in a system-wide denial of service."], "name": "CVE-2026-68138", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:enterprise_linux_nvidia:", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux for NVIDIA 26"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-08-10T11:59:01Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-68138\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-68138\nhttps://git.kernel.org/stable/c/f43ee0c0730d6191629b5ee1ceae27b1ebfdc047\nhttps://git.kernel.org/stable/c/fb29e1b41052488ee3f2d115d4a870497ebd7f7d"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[470502de5bdb1ed0def643a4458593a40b8f6b66,fb29e1b41052488ee3f2d115d4a870497ebd7f7d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[470502de5bdb1ed0def643a4458593a40b8f6b66,f43ee0c0730d6191629b5ee1ceae27b1ebfdc047)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "5.1"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.1)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.6,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-10T14:15:03.850566+00:00", "updated": "2026-10-20T05:00:16.562515+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-362", "CWE-364"]}