{"id":"CVE-2026-89732","revision":null,"records":[{"revision":"5ced5f28295b4f19ba67e0bf5ea50c43","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89732","aliases":[],"title":"usb: gadget: f_fs: Prevent deadlock during ep0 read loop","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_fs: Prevent deadlock during ep0 read loop\n\nCurrently, ffs_ep0_read() holds ffs->mutex when it prepares to go to\nsleep waiting for an event. When no setup events are pending, it calls\nwait_event_interruptible_exclusive_locked_irq() with the mutex still\nheld. The wait macro deliberately drops the waitqueue spinlock before\nsleeping but does not drop the mutex.\n\nIf a userspace daemon is polling ep0 via read() and the gadget is\nasynchronously torn down via configfs (e.g., echo \"\" > UDC), a\ndeadlock can occur:\n\n1. The configfs teardown calls functionfs_unbind(), which queues a\n FUNCTIONFS_UNBIND event.\n2. The daemon wakes up, consumes the event, and drops the mutex.\n3. However, if the daemon loops and immediately issues another read()\n before exiting, it reacquires ffs->mutex and again goes into an\n interruptible sleep.\n4. Meanwhile, functionfs_unbind() continues execution and attempts to\n acquire ffs->mutex to tear down ep0req.\n5. The kernel deadlocks because the configfs thread is stuck in an\n uninterruptible sleep waiting for the mutex, while the userspace\n daemon is in an interruptible sleep holding the mutex forever\n because no more events will arrive.\n\nTo fix this, we drop both the waitqueue spinlock and ffs->mutex before\ngoing to sleep, and use wait_event_interruptible_exclusive() instead.\nUpon waking up, we jump back to the `retry` label to safely reacquire\nthe mutex and re-evaluate the state machine. By not sleeping with\nffs->mutex held, we natively decouple gadget teardowns (which require\nthe mutex) from userspace polling.","state":0,"publishedAt":"2026-09-11T19:46:41.974+00:00","modifiedAt":"2026-10-19T08:51:45.542+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"drivers/usb/gadget/function/f_fs.c\"\n ],\n \"versions\": [\n {\n \"version\": \"ddf8abd2599491cbad959c700b90ba72a5dce8d0\",\n \"lessThan\": \"fbe3db4b650c284df8eb4cb68eebcf270cf861b5\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ddf8abd2599491cbad959c700b90ba72a5dce8d0\",\n \"lessThan\": \"30430509c156e1df2bdafd5f1cadb160e53db5d6\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ddf8abd2599491cbad959c700b90ba72a5dce8d0\",\n \"lessThan\": \"bafddd0f20b5228760be303aa69c58502e92309c\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ddf8abd2599491cbad959c700b90ba72a5dce8d0\",\n \"lessThan\": \"b0a6bfac0c3c3edf5b2ecaee87a09234601fe78d\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ddf8abd2599491cbad959c700b90ba72a5dce8d0\",\n \"lessThan\": \"fd20cc68bbdb5620696ac108e8f2efd180fe2c1a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ddf8abd2599491cbad959c700b90ba72a5dce8d0\",\n \"lessThan\": \"34e88f53614640b59039a46717fb6142e9871022\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ddf8abd2599491cbad959c700b90ba72a5dce8d0\",\n \"lessThan\": \"eac233e63f9db82ba874e3cccafaafab162999e0\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"ddf8abd2599491cbad959c700b90ba72a5dce8d0\",\n \"lessThan\": \"569dd7e5dcffe1e1c6b26ca2cd3be57eb433e082\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"drivers/usb/gadget/function/f_fs.c\"\n ],\n \"versions\": [\n {\n \"version\": \"2.6.35\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"2.6.35\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.270\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.221\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.188\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.157\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.109\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.50\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.4\",\n \"lessThanOrEqual\": \"7.2.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.3\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/fbe3db4b650c284df8eb4cb68eebcf270cf861b5","https://git.kernel.org/stable/c/30430509c156e1df2bdafd5f1cadb160e53db5d6","https://git.kernel.org/stable/c/bafddd0f20b5228760be303aa69c58502e92309c","https://git.kernel.org/stable/c/b0a6bfac0c3c3edf5b2ecaee87a09234601fe78d","https://git.kernel.org/stable/c/fd20cc68bbdb5620696ac108e8f2efd180fe2c1a","https://git.kernel.org/stable/c/34e88f53614640b59039a46717fb6142e9871022","https://git.kernel.org/stable/c/eac233e63f9db82ba874e3cccafaafab162999e0","https://git.kernel.org/stable/c/569dd7e5dcffe1e1c6b26ca2cd3be57eb433e082"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89732","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89732","identifiers":["CVE-2026-89732"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-09T04:03:51.7811525+00:00","complete":true,"records":1769,"lastAttemptAt":"2026-11-09T04:03:51.7811525+00:00","lastSuccessAt":"2026-11-09T04:03:51.9477173+00:00","error":null,"lastVerifiedAt":"2026-11-09T04:03:51.9477231+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-24e6fde7b744113daefb8f6135035fb8a5c69c9617c9c0d40574a0376532ffd3-246bcd291098e4bae24ec491a133b97526d1f4514f8eb34817e1ec280d43b276","complete":true,"records":421286,"lastAttemptAt":"2026-11-09T04:02:14.2951792+00:00","lastSuccessAt":"2026-11-09T04:02:14.2751612+00:00","error":null,"lastVerifiedAt":"2026-11-09T04:02:14.2951792+00:00","snapshotPublishedAt":"2026-11-09T03:29:47+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-0e1130a95bab4b43bc10624fd5ee853a","complete":false,"records":13654,"lastAttemptAt":"2026-11-09T04:16:03.8367163+00:00","lastSuccessAt":"2026-11-09T04:16:03.832+00:00","error":"8 identifier lookups failed; latest failures include HTTP 403. Other identifiers were checked independently.","lastVerifiedAt":"2026-11-09T04:16:03.832+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13653,"expectedIdentifiers":13706,"failedIdentifiers":8},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-09T04:03:51.7811525+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T04:03:51.7811525+00:00","lastSuccessAt":"2026-11-09T04:03:51.948408+00:00","error":null,"lastVerifiedAt":"2026-11-09T04:03:51.9484081+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-5a44a451442747cb81d83104fe1e7771","complete":true,"records":13666,"lastAttemptAt":"2026-11-09T04:03:52.3882913+00:00","lastSuccessAt":"2026-11-09T02:08:52.274+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:52.274+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-09T04:03:51.3592849+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-09T04:03:51.3592849+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-09T04:02:14.6671491+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-09T04:02:14.6671491+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-3b1150af6d7ada2c07356cbab4ead5224c1485027890f71c71d0742cddf0b9e8","complete":true,"records":3055,"lastAttemptAt":"2026-11-09T04:03:51.7519249+00:00","lastSuccessAt":"2026-11-09T00:02:23.4330288+00:00","error":null,"lastVerifiedAt":"2026-11-09T04:03:51.7519249+00:00","snapshotPublishedAt":"2026-11-08T23:17:54+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-6a1c845b1938b1aa788f0e95c9ac8a8d5a1f07caed5d155840b0616b548c1455","complete":true,"records":231296,"lastAttemptAt":"2026-11-09T04:03:51.2380069+00:00","lastSuccessAt":"2026-11-09T04:03:49.859595+00:00","error":null,"lastVerifiedAt":"2026-11-09T04:03:51.2380069+00:00","snapshotPublishedAt":"2026-11-09T03:33:06+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}