{"id":"CVE-2026-90201","state":"PUBLISHED","title":"net: page_pool: fix UAF in __page_pool_release_netmem_dma on xa_cmpxchg race","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: page_pool: fix UAF in __page_pool_release_netmem_dma on xa_cmpxchg race\n\nThis bug was discovered while testing the hns3 driver under channel\nreconfiguration (`ethtool -L` / `ethtool -G`) with iperf3 traffic on\narm64. The race is intermittently triggered when page_pool_destroy()\nruns page_pool_scrub() concurrently with page return via\npage_pool_put_netmem() on a different CPU. A WARN in\npage_pool_clear_pp_info() surfaced the dangling DMA index bits left\nby the cmpxchg loser, which led to the investigation.\n\npage_pool_scrub() iterates pool->dma_mapped via xa_for_each() with no\npage ref held. __page_pool_release_netmem_dma() currently reads and\nwrites netmem fields (dma_addr, DMA index bits in pp_magic) after\nxa_cmpxchg() returns. The unref path calls put_page() unconditionally\nregardless of the cmpxchg outcome; when it loses the cmpxchg, it still\nfrees the page before the scrub winner finishes these netmem accesses,\nso scrub touches a freed page -- a Use-After-Free.\n\nFix this by splitting the DMA release into two functions:\n\n1. __page_pool_unmap_netmem_dma() caches dma_addr before xa_cmpxchg(),\n   does the cmpxchg to remove the DMA mapping, and calls dma_unmap on\n   the cached address. It never touches netmem fields after the cmpxchg,\n   making it safe for the scrub path which holds no page ref.\n\n2. __page_pool_release_netmem_dma() wraps the above and additionally\n   clears dma_addr and DMA index bits in netmem fields. This is safe\n   only when the caller holds a page ref, so it is used by the return\n   path (page_pool_return_netmem).\n\nThe scrub path calls __page_pool_unmap_netmem_dma() directly; the return\npath calls __page_pool_release_netmem_dma().","publishedAt":"2026-09-17T16:07:18.838Z","updatedAt":"2026-10-19T08:59:37.392Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4f51fb0d257ff4d406ec27966902de075e3b118e","status":"affected","lessThan":"bbfef303f980c1c078b8fa142e10a0e2fbcdd247","versionType":"git"},{"version":"ee62ce7a1d909ccba0399680a03c2dee83bcae95","status":"affected","lessThan":"424a9fc4876cc7f28e9cb0aa8d92e920d726e350","versionType":"git"},{"version":"ee62ce7a1d909ccba0399680a03c2dee83bcae95","status":"affected","lessThan":"9b65b0253ad5a66f73efee9a79a21a1e2b57cf59","versionType":"git"},{"version":"ee62ce7a1d909ccba0399680a03c2dee83bcae95","status":"affected","lessThan":"24ef02f934eeb48830cff6b739abc3c62b1d107b","versionType":"git"},{"version":"c30ae60f41f9edd6e1b5cad41cf28ce04dae39e4","status":"affected","versionType":"git"},{"version":"6.12.34","status":"affected","lessThan":"6.12.110","versionType":"semver"},{"version":"6.15.3","status":"affected","lessThan":"6.16","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/page_pool.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/page_pool.c"]}],"references":["https://git.kernel.org/stable/c/bbfef303f980c1c078b8fa142e10a0e2fbcdd247","https://git.kernel.org/stable/c/424a9fc4876cc7f28e9cb0aa8d92e920d726e350","https://git.kernel.org/stable/c/9b65b0253ad5a66f73efee9a79a21a1e2b57cf59","https://git.kernel.org/stable/c/24ef02f934eeb48830cff6b739abc3c62b1d107b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90201.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90201","state":"PUBLISHED","datePublished":"2026-09-17T16:07:18.838Z","dateUpdated":"2026-10-19T08:59:37.392Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.792Z"},"containers":{"cna":{"title":"net: page_pool: fix UAF in __page_pool_release_netmem_dma on xa_cmpxchg race","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: page_pool: fix UAF in __page_pool_release_netmem_dma on xa_cmpxchg race\n\nThis bug was discovered while testing the hns3 driver under channel\nreconfiguration (`ethtool -L` / `ethtool -G`) with iperf3 traffic on\narm64. The race is intermittently triggered when page_pool_destroy()\nruns page_pool_scrub() concurrently with page return via\npage_pool_put_netmem() on a different CPU. A WARN in\npage_pool_clear_pp_info() surfaced the dangling DMA index bits left\nby the cmpxchg loser, which led to the investigation.\n\npage_pool_scrub() iterates pool->dma_mapped via xa_for_each() with no\npage ref held. __page_pool_release_netmem_dma() currently reads and\nwrites netmem fields (dma_addr, DMA index bits in pp_magic) after\nxa_cmpxchg() returns. The unref path calls put_page() unconditionally\nregardless of the cmpxchg outcome; when it loses the cmpxchg, it still\nfrees the page before the scrub winner finishes these netmem accesses,\nso scrub touches a freed page -- a Use-After-Free.\n\nFix this by splitting the DMA release into two functions:\n\n1. __page_pool_unmap_netmem_dma() caches dma_addr before xa_cmpxchg(),\n   does the cmpxchg to remove the DMA mapping, and calls dma_unmap on\n   the cached address. It never touches netmem fields after the cmpxchg,\n   making it safe for the scrub path which holds no page ref.\n\n2. __page_pool_release_netmem_dma() wraps the above and additionally\n   clears dma_addr and DMA index bits in netmem fields. This is safe\n   only when the caller holds a page ref, so it is used by the return\n   path (page_pool_return_netmem).\n\nThe scrub path calls __page_pool_unmap_netmem_dma() directly; the return\npath calls __page_pool_release_netmem_dma()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4f51fb0d257ff4d406ec27966902de075e3b118e","status":"affected","lessThan":"bbfef303f980c1c078b8fa142e10a0e2fbcdd247","versionType":"git"},{"version":"ee62ce7a1d909ccba0399680a03c2dee83bcae95","status":"affected","lessThan":"424a9fc4876cc7f28e9cb0aa8d92e920d726e350","versionType":"git"},{"version":"ee62ce7a1d909ccba0399680a03c2dee83bcae95","status":"affected","lessThan":"9b65b0253ad5a66f73efee9a79a21a1e2b57cf59","versionType":"git"},{"version":"ee62ce7a1d909ccba0399680a03c2dee83bcae95","status":"affected","lessThan":"24ef02f934eeb48830cff6b739abc3c62b1d107b","versionType":"git"},{"version":"c30ae60f41f9edd6e1b5cad41cf28ce04dae39e4","status":"affected","versionType":"git"},{"version":"6.12.34","status":"affected","lessThan":"6.12.110","versionType":"semver"},{"version":"6.15.3","status":"affected","lessThan":"6.16","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/page_pool.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/page_pool.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/bbfef303f980c1c078b8fa142e10a0e2fbcdd247"},{"url":"https://git.kernel.org/stable/c/424a9fc4876cc7f28e9cb0aa8d92e920d726e350"},{"url":"https://git.kernel.org/stable/c/9b65b0253ad5a66f73efee9a79a21a1e2b57cf59"},{"url":"https://git.kernel.org/stable/c/24ef02f934eeb48830cff6b739abc3c62b1d107b"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:59:37.392Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.34","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}