{"id":"CVE-2026-64263","state":"PUBLISHED","title":"fuse-uring: fix moving cancelled entry to ent_in_userspace list","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix moving cancelled entry to ent_in_userspace list\n\nfuse_uring_cancel() moves entries that are available (these have no reqs\nattached) to the ent_in_userspace list. ent_list_request_expired()\nchecks the first entry on ent_in_userspace and dereferences\nent->fuse_req unconditionally, which will crash on a cancelled entry\nthat was moved to this list.\n\nFix this by freeing the entry and dropping queue_refs directly in\nfuse_uring_cancel(). This is safe because cancel is the cancel handler\nitself - after io_uring_cmd_done(), no more cancels will be dispatched\nfor this command, and teardown serializes with cancel via queue->lock.\n\nSince cancel now decrements queue_refs, fuse_uring_abort() must no\nlonger gate fuse_uring_abort_end_requests() on queue_refs > 0, as\ncancelled entries may have already dropped queue_refs while requests are\nstill queued. Remove the gate so abort always flushes requests and stops\nqueues.","publishedAt":"2026-07-25T08:49:13.217Z","updatedAt":"2026-08-17T04:52:16.831Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4fea593e625cd50d4d11be227007849b12f17bfb","status":"affected","lessThan":"50f3e03db823cabc41fe35c27d77c2bdb112baad","versionType":"git"},{"version":"4fea593e625cd50d4d11be227007849b12f17bfb","status":"affected","lessThan":"e8afc85acdf329361b2d8df2ad9b52364686235f","versionType":"git"},{"version":"4fea593e625cd50d4d11be227007849b12f17bfb","status":"affected","lessThan":"198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fuse/dev_uring.c","fs/fuse/dev_uring_i.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","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":["fs/fuse/dev_uring.c","fs/fuse/dev_uring_i.h"]}],"references":["https://git.kernel.org/stable/c/50f3e03db823cabc41fe35c27d77c2bdb112baad","https://git.kernel.org/stable/c/e8afc85acdf329361b2d8df2ad9b52364686235f","https://git.kernel.org/stable/c/198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64263.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64263","state":"PUBLISHED","datePublished":"2026-07-25T08:49:13.217Z","dateUpdated":"2026-08-17T04:52:16.831Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.774Z"},"containers":{"cna":{"title":"fuse-uring: fix moving cancelled entry to ent_in_userspace list","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix moving cancelled entry to ent_in_userspace list\n\nfuse_uring_cancel() moves entries that are available (these have no reqs\nattached) to the ent_in_userspace list. ent_list_request_expired()\nchecks the first entry on ent_in_userspace and dereferences\nent->fuse_req unconditionally, which will crash on a cancelled entry\nthat was moved to this list.\n\nFix this by freeing the entry and dropping queue_refs directly in\nfuse_uring_cancel(). This is safe because cancel is the cancel handler\nitself - after io_uring_cmd_done(), no more cancels will be dispatched\nfor this command, and teardown serializes with cancel via queue->lock.\n\nSince cancel now decrements queue_refs, fuse_uring_abort() must no\nlonger gate fuse_uring_abort_end_requests() on queue_refs > 0, as\ncancelled entries may have already dropped queue_refs while requests are\nstill queued. Remove the gate so abort always flushes requests and stops\nqueues."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4fea593e625cd50d4d11be227007849b12f17bfb","status":"affected","lessThan":"50f3e03db823cabc41fe35c27d77c2bdb112baad","versionType":"git"},{"version":"4fea593e625cd50d4d11be227007849b12f17bfb","status":"affected","lessThan":"e8afc85acdf329361b2d8df2ad9b52364686235f","versionType":"git"},{"version":"4fea593e625cd50d4d11be227007849b12f17bfb","status":"affected","lessThan":"198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fuse/dev_uring.c","fs/fuse/dev_uring_i.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","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":["fs/fuse/dev_uring.c","fs/fuse/dev_uring_i.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/50f3e03db823cabc41fe35c27d77c2bdb112baad"},{"url":"https://git.kernel.org/stable/c/e8afc85acdf329361b2d8df2ad9b52364686235f"},{"url":"https://git.kernel.org/stable/c/198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:52:16.831Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}