{"id":"CVE-2026-31435","state":"PUBLISHED","title":"netfs: Fix read abandonment during retry","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix read abandonment during retry\n\nUnder certain circumstances, all the remaining subrequests from a read\nrequest will get abandoned during retry.  The abandonment process expects\nthe 'subreq' variable to be set to the place to start abandonment from, but\nit doesn't always have a useful value (it will be uninitialised on the\nfirst pass through the loop and it may point to a deleted subrequest on\nlater passes).\n\nFix the first jump to \"abandon:\" to set subreq to the start of the first\nsubrequest expected to need retry (which, in this abandonment case, turned\nout unexpectedly to no longer have NEED_RETRY set).\n\nAlso clear the subreq pointer after discarding superfluous retryable\nsubrequests to cause an oops if we do try to access it.","publishedAt":"2026-04-22T13:53:35.032Z","updatedAt":"2026-10-19T18:35:47.887Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ee4cdf7ba857a894ad1650d6ab77669cbbfa329e","status":"affected","lessThan":"3e5fd8f53b575ff2188f82071da19c977ca56c41","versionType":"git"},{"version":"ee4cdf7ba857a894ad1650d6ab77669cbbfa329e","status":"affected","lessThan":"8f2f2bd128a8d9edbc1e785760da54ada3df69b7","versionType":"git"},{"version":"ee4cdf7ba857a894ad1650d6ab77669cbbfa329e","status":"affected","lessThan":"7e57523490cd2efb52b1ea97f2e0a74c0fb634cd","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/netfs/read_retry.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.12","versionType":"semver"},{"version":"6.18.21","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.11","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/netfs/read_retry.c"]}],"references":["https://git.kernel.org/stable/c/3e5fd8f53b575ff2188f82071da19c977ca56c41","https://git.kernel.org/stable/c/8f2f2bd128a8d9edbc1e785760da54ada3df69b7","https://git.kernel.org/stable/c/7e57523490cd2efb52b1ea97f2e0a74c0fb634cd"],"weaknesses":["CWE-457"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31435.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31435","state":"PUBLISHED","datePublished":"2026-04-22T13:53:35.032Z","dateUpdated":"2026-10-19T18:35:47.887Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.089Z"},"containers":{"cna":{"title":"netfs: Fix read abandonment during retry","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix read abandonment during retry\n\nUnder certain circumstances, all the remaining subrequests from a read\nrequest will get abandoned during retry.  The abandonment process expects\nthe 'subreq' variable to be set to the place to start abandonment from, but\nit doesn't always have a useful value (it will be uninitialised on the\nfirst pass through the loop and it may point to a deleted subrequest on\nlater passes).\n\nFix the first jump to \"abandon:\" to set subreq to the start of the first\nsubrequest expected to need retry (which, in this abandonment case, turned\nout unexpectedly to no longer have NEED_RETRY set).\n\nAlso clear the subreq pointer after discarding superfluous retryable\nsubrequests to cause an oops if we do try to access it."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ee4cdf7ba857a894ad1650d6ab77669cbbfa329e","status":"affected","lessThan":"3e5fd8f53b575ff2188f82071da19c977ca56c41","versionType":"git"},{"version":"ee4cdf7ba857a894ad1650d6ab77669cbbfa329e","status":"affected","lessThan":"8f2f2bd128a8d9edbc1e785760da54ada3df69b7","versionType":"git"},{"version":"ee4cdf7ba857a894ad1650d6ab77669cbbfa329e","status":"affected","lessThan":"7e57523490cd2efb52b1ea97f2e0a74c0fb634cd","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/netfs/read_retry.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.12","versionType":"semver"},{"version":"6.18.21","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.11","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/netfs/read_retry.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3e5fd8f53b575ff2188f82071da19c977ca56c41"},{"url":"https://git.kernel.org/stable/c/8f2f2bd128a8d9edbc1e785760da54ada3df69b7"},{"url":"https://git.kernel.org/stable/c/7e57523490cd2efb52b1ea97f2e0a74c0fb634cd"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable netfs retry path processes read results from network filesystem peers such as SMB/CIFS, Ceph, AFS, 9P, and NFS/fscache-backed paths. A malicious or compromised remote filesystem server can drive retry/short-read behavior over the network.\nAC:L - The trigger is retry/abandonment state during ordinary read handling, and a malicious peer can influence short reads, retryable errors, reconnects, or malformed responses. No uncontrollable race or rare memory layout condition is required to reach the vulnerable path.\nPR:N - The attacker can be the remote filesystem peer and needs no privileges on the vulnerable client kernel. Local credentials may be needed by a victim/client to use the mount, but not by the remote attacker.\nUI:R - The client must mount/use the network filesystem and perform or have a process perform a read that reaches the affected netfs path. Opening or reading a file is victim-side interaction.\nS:U - The impact remains within the kernel/client system security authority. This is not a VM escape, IOMMU bypass, or cross-authority boundary escape.\nC:H - The bug can use an uninitialized or stale freed subrequest pointer in list traversal and field access. That kernel memory corruption/use-after-free is defensibly exploitable for information disclosure.\nI:H - The stale subrequest case can write fields and flags through a freed object and continue list traversal from freed memory. This is kernel memory corruption with potential arbitrary write/control-flow impact.\nA:H - Even without full exploitation, dereferencing an uninitialized or freed subrequest pointer can oops or panic the kernel. A malicious peer can repeatedly induce the read retry condition to cause denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:22:28.838Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"6.18.21"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"6.19.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-31435","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:09:13.729814Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-457","lang":"en","type":"CWE","description":"CWE-457 Use of Uninitialized Variable"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T18:35:47.887Z"}}]}}}