{"id":"CVE-2026-74290","state":"PUBLISHED","title":"net/sched: cls_flow: Dont expose folded kernel pointers","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_flow: Dont expose folded kernel pointers\n\nThe flow classifier falls back to addr_fold() for fields that are missing\nfrom packet headers. In map mode, userspace controls mask, xor, rshift,\naddend and divisor, and can observe the resulting classid through class\nstatistics. This allows a tc classifier in a user/network namespace to\nrecover the 32-bit folded value of skb->sk, skb_dst() or skb_nfct().\n\nAlign with standard kernel practices for pointer hashing and replace the\nXOR folding with a keyed siphash (which is cryptographically secure)","publishedAt":"2026-08-15T05:57:57.004Z","updatedAt":"2026-08-17T05:16:36.420Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"19f2ecf8ea564562c7e7a919cf38068dd9aa1c96","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"3d054001860270748405a3f9270c5fa0bf7ffc19","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"fb31fbe51c233f3bf47021121f63d2e42cac2d08","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"0a8b5b74f0e6b6b9ce453bcfa4baa502c4c7577a","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"6151159618198675e01c391676e579738286c135","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"f294fc71c4a0fa4964f6428a1b4e7929c1d83125","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/cls_flow.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.25","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.25","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/cls_flow.c"]}],"references":["https://git.kernel.org/stable/c/19f2ecf8ea564562c7e7a919cf38068dd9aa1c96","https://git.kernel.org/stable/c/3d054001860270748405a3f9270c5fa0bf7ffc19","https://git.kernel.org/stable/c/fb31fbe51c233f3bf47021121f63d2e42cac2d08","https://git.kernel.org/stable/c/0a8b5b74f0e6b6b9ce453bcfa4baa502c4c7577a","https://git.kernel.org/stable/c/6151159618198675e01c391676e579738286c135","https://git.kernel.org/stable/c/f294fc71c4a0fa4964f6428a1b4e7929c1d83125"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74290.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74290","state":"PUBLISHED","datePublished":"2026-08-15T05:57:57.004Z","dateUpdated":"2026-08-17T05:16:36.420Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.881Z"},"containers":{"cna":{"title":"net/sched: cls_flow: Dont expose folded kernel pointers","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_flow: Dont expose folded kernel pointers\n\nThe flow classifier falls back to addr_fold() for fields that are missing\nfrom packet headers. In map mode, userspace controls mask, xor, rshift,\naddend and divisor, and can observe the resulting classid through class\nstatistics. This allows a tc classifier in a user/network namespace to\nrecover the 32-bit folded value of skb->sk, skb_dst() or skb_nfct().\n\nAlign with standard kernel practices for pointer hashing and replace the\nXOR folding with a keyed siphash (which is cryptographically secure)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"19f2ecf8ea564562c7e7a919cf38068dd9aa1c96","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"3d054001860270748405a3f9270c5fa0bf7ffc19","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"fb31fbe51c233f3bf47021121f63d2e42cac2d08","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"0a8b5b74f0e6b6b9ce453bcfa4baa502c4c7577a","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"6151159618198675e01c391676e579738286c135","versionType":"git"},{"version":"e5dfb815181fcb186d6080ac3a091eadff2d98fe","status":"affected","lessThan":"f294fc71c4a0fa4964f6428a1b4e7929c1d83125","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/cls_flow.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.25","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.25","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/cls_flow.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/19f2ecf8ea564562c7e7a919cf38068dd9aa1c96"},{"url":"https://git.kernel.org/stable/c/3d054001860270748405a3f9270c5fa0bf7ffc19"},{"url":"https://git.kernel.org/stable/c/fb31fbe51c233f3bf47021121f63d2e42cac2d08"},{"url":"https://git.kernel.org/stable/c/0a8b5b74f0e6b6b9ce453bcfa4baa502c4c7577a"},{"url":"https://git.kernel.org/stable/c/6151159618198675e01c391676e579738286c135"},{"url":"https://git.kernel.org/stable/c/f294fc71c4a0fa4964f6428a1b4e7929c1d83125"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:16:36.420Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.25","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}