{"id":"CVE-2022-49921","state":"PUBLISHED","title":"net: sched: Fix use after free in red_enqueue()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: sched: Fix use after free in red_enqueue()\n\nWe can't use \"skb\" again after passing it to qdisc_enqueue().  This is\nbasically identical to commit 2f09707d0c97 (\"sch_sfb: Also store skb\nlen before calling child enqueue\").","publishedAt":"2025-05-01T14:11:00.309Z","updatedAt":"2026-08-05T08:56:42.811Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"795afe0b9bb6c915f0299a8e309936519be01619","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"a238cdcf2bdc72207c74375fc8be13ee549ca9db","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"e877f8fa49fbccc63cb2df2e9179bddc695b825a","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"52e0429471976785c155bfbf51d80990c6cd46e2","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"5960b9081baca85cc7dcb14aec1de85999ea9d36","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"fc4b50adb400ee5ec527a04073174e8e73a139fa","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"170e5317042c302777ed6d59fdb84af9b0219d4e","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"8bdc2acd420c6f3dd1f1c78750ec989f02a1e2b9","versionType":"git"},{"version":"ab0b3b9dbf559a5633d460e748144697bd2d3aa3","status":"affected","versionType":"git"},{"version":"4.4.163","status":"affected","lessThan":"4.5","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_red.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.7","versionType":"semver"},{"version":"4.9.333","status":"unaffected","lessThanOrEqual":"4.9.*","versionType":"semver"},{"version":"4.14.299","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.265","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.224","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.154","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.78","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.0.8","status":"unaffected","lessThanOrEqual":"6.0.*","versionType":"semver"},{"version":"6.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_red.c"]}],"references":["https://git.kernel.org/stable/c/795afe0b9bb6c915f0299a8e309936519be01619","https://git.kernel.org/stable/c/a238cdcf2bdc72207c74375fc8be13ee549ca9db","https://git.kernel.org/stable/c/e877f8fa49fbccc63cb2df2e9179bddc695b825a","https://git.kernel.org/stable/c/52e0429471976785c155bfbf51d80990c6cd46e2","https://git.kernel.org/stable/c/5960b9081baca85cc7dcb14aec1de85999ea9d36","https://git.kernel.org/stable/c/fc4b50adb400ee5ec527a04073174e8e73a139fa","https://git.kernel.org/stable/c/170e5317042c302777ed6d59fdb84af9b0219d4e","https://git.kernel.org/stable/c/8bdc2acd420c6f3dd1f1c78750ec989f02a1e2b9"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/49xxx/CVE-2022-49921.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49921","state":"PUBLISHED","datePublished":"2025-05-01T14:11:00.309Z","dateUpdated":"2026-08-05T08:56:42.811Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-05-01T14:05:17.252Z"},"containers":{"cna":{"title":"net: sched: Fix use after free in red_enqueue()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: sched: Fix use after free in red_enqueue()\n\nWe can't use \"skb\" again after passing it to qdisc_enqueue().  This is\nbasically identical to commit 2f09707d0c97 (\"sch_sfb: Also store skb\nlen before calling child enqueue\")."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"795afe0b9bb6c915f0299a8e309936519be01619","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"a238cdcf2bdc72207c74375fc8be13ee549ca9db","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"e877f8fa49fbccc63cb2df2e9179bddc695b825a","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"52e0429471976785c155bfbf51d80990c6cd46e2","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"5960b9081baca85cc7dcb14aec1de85999ea9d36","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"fc4b50adb400ee5ec527a04073174e8e73a139fa","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"170e5317042c302777ed6d59fdb84af9b0219d4e","versionType":"git"},{"version":"d7f4f332f082c4d4ba53582f902ed6b44fd6f45e","status":"affected","lessThan":"8bdc2acd420c6f3dd1f1c78750ec989f02a1e2b9","versionType":"git"},{"version":"ab0b3b9dbf559a5633d460e748144697bd2d3aa3","status":"affected","versionType":"git"},{"version":"4.4.163","status":"affected","lessThan":"4.5","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_red.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.7","versionType":"semver"},{"version":"4.9.333","status":"unaffected","lessThanOrEqual":"4.9.*","versionType":"semver"},{"version":"4.14.299","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.265","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.224","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.154","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.78","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.0.8","status":"unaffected","lessThanOrEqual":"6.0.*","versionType":"semver"},{"version":"6.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/sch_red.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/795afe0b9bb6c915f0299a8e309936519be01619"},{"url":"https://git.kernel.org/stable/c/a238cdcf2bdc72207c74375fc8be13ee549ca9db"},{"url":"https://git.kernel.org/stable/c/e877f8fa49fbccc63cb2df2e9179bddc695b825a"},{"url":"https://git.kernel.org/stable/c/52e0429471976785c155bfbf51d80990c6cd46e2"},{"url":"https://git.kernel.org/stable/c/5960b9081baca85cc7dcb14aec1de85999ea9d36"},{"url":"https://git.kernel.org/stable/c/fc4b50adb400ee5ec527a04073174e8e73a139fa"},{"url":"https://git.kernel.org/stable/c/170e5317042c302777ed6d59fdb84af9b0219d4e"},{"url":"https://git.kernel.org/stable/c/8bdc2acd420c6f3dd1f1c78750ec989f02a1e2b9"}],"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 in the tc/qdisc RED enqueue path, reached by configuring a qdisc via netlink (RTM_NEWQDISC) and sending traffic through that device; per kernel guidance, tc/qdisc bugs are Local.\nAC:L - An attacker who configures RED with a child that frees skbs on successful enqueue (e.g. CAKE with GSO split or TBF GSO segmentation) can deterministically trigger the UAF by sending GSO packets; no conditions outside attacker control are required.\nPR:L - Creating/modifying qdiscs requires CAP_NET_ADMIN, but that capability is obtainable in an unprivileged user+network namespace via unshare/clone, so Privileges Required is Low rather than High.\nUI:N - Once the attacker has set up the qdisc hierarchy in their namespace, they can trigger the UAF by sending packets themselves with no victim interaction.\nS:U - This is a standard in-kernel memory corruption/privilege-escalation issue within the same OS security authority; it does not cross VM, IOMMU, or other security boundaries.\nC:H - This is a use-after-free on an sk_buff; per CVSS kernel guidance, UAFs enable control of freed object contents and are scored as High confidentiality impact.\nI:H - Use-after-free of sk_buff enables heap reuse/spraying and can be leveraged for arbitrary write or control-flow hijacking, so Integrity is High.\nA:H - Use-after-free of a freed skb can cause kernel oops/panic when the reclaimed memory is accessed or unmapped, so Availability is High."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:56:42.811Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"4.9.333"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"4.14.299"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"4.19.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.4.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.10.154"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.15.78"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.0.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4.163"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.8,"attackVector":"LOCAL","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2025-10-01T14:58:28.989555Z","id":"CVE-2022-49921","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","type":"CWE","lang":"en","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2025-10-01T14:58:31.797Z"}}]}}}