{"id":"CVE-2026-89741","state":"PUBLISHED","title":"Revert \"media: v4l2-dev: fix error handling in __video_register_device()\"","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"media: v4l2-dev: fix error handling in __video_register_device()\"\n\nThis reverts commit 2a934fdb01db6458288fc9386d3d8ceba6dd551a.\n\nThe intentions of that patch were good, but it doesn't work.\n\nThe idea is that if device_register fails, you have to do a put_device\nto let the ref counter release resources.\n\nHowever, the V4L2 API says that if video_register_device() fails, then\nyou have to call video_device_release(), which kfree()s the video_device\nstruct.\n\nBut the put_device() will already have freed the struct, so you end\nup in a double-free scenario.\n\nThere is not really a good way of fixing this without breaking\nvideo_register_device() into two parts, one that initializes everything,\nand one that does the actual device_register, and then converting all\nV4L2 drivers to this new model.\n\nThat is a massive job, and it is very unlikely that device_register\nwill fail.\n\nSo rather than ending up in a double-free scenario, just revert this\npatch, and in that case we'll have a small memory leak. Which is a lot\nmore robust.","publishedAt":"2026-09-11T19:46:47.877Z","updatedAt":"2026-10-19T08:51:55.196Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e5c8e62ae551e0ad2e15412aa0c57c2856d59677","status":"affected","lessThan":"8b998c171ed875e402e1fd1c5cd619e4ca05e9c1","versionType":"git"},{"version":"8b451a9a46f2bfc510e6d5c2492df91647586184","status":"affected","lessThan":"3de14b4f681a1b3c6d375d98d9d37a55ebb85349","versionType":"git"},{"version":"b6be1f5633eae200af2527e9eeb7f51be5739b0f","status":"affected","lessThan":"8027f82c0f5474ed72448e160ee9778051fa1f49","versionType":"git"},{"version":"ae7b143e05b36fc69d6571751855946cc45064c6","status":"affected","lessThan":"2ac009a65d2385e9f0799eaf9d9694a29153a161","versionType":"git"},{"version":"2429bb9fad88c8fa84c4956b0a21cf5afe5e92b7","status":"affected","lessThan":"712ca1cf756de2557a116e0df55791bac0c9f99e","versionType":"git"},{"version":"2a934fdb01db6458288fc9386d3d8ceba6dd551a","status":"affected","lessThan":"aad08b5f67d2a8116e1a00bce2611c1513b10bce","versionType":"git"},{"version":"2a934fdb01db6458288fc9386d3d8ceba6dd551a","status":"affected","lessThan":"ce792b94e03882108019ba996c1a7c4d4e09be2c","versionType":"git"},{"version":"2a934fdb01db6458288fc9386d3d8ceba6dd551a","status":"affected","lessThan":"e7600f5cee5de14065f950807931d6e6d40fb2d7","versionType":"git"},{"version":"ee141706e701356dda41c6fed9ee18bf427c28e3","status":"affected","versionType":"git"},{"version":"4451412739ed33a49b34624299394ee575116d0c","status":"affected","versionType":"git"},{"version":"5.10.239","status":"affected","lessThan":"5.10.270","versionType":"semver"},{"version":"5.15.186","status":"affected","lessThan":"5.15.221","versionType":"semver"},{"version":"6.1.142","status":"affected","lessThan":"6.1.188","versionType":"semver"},{"version":"6.6.95","status":"affected","lessThan":"6.6.157","versionType":"semver"},{"version":"6.12.35","status":"affected","lessThan":"6.12.109","versionType":"semver"},{"version":"5.4.295","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"6.15.4","status":"affected","lessThan":"6.16","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/media/v4l2-core/v4l2-dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","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":["drivers/media/v4l2-core/v4l2-dev.c"]}],"references":["https://git.kernel.org/stable/c/8b998c171ed875e402e1fd1c5cd619e4ca05e9c1","https://git.kernel.org/stable/c/3de14b4f681a1b3c6d375d98d9d37a55ebb85349","https://git.kernel.org/stable/c/8027f82c0f5474ed72448e160ee9778051fa1f49","https://git.kernel.org/stable/c/2ac009a65d2385e9f0799eaf9d9694a29153a161","https://git.kernel.org/stable/c/712ca1cf756de2557a116e0df55791bac0c9f99e","https://git.kernel.org/stable/c/aad08b5f67d2a8116e1a00bce2611c1513b10bce","https://git.kernel.org/stable/c/ce792b94e03882108019ba996c1a7c4d4e09be2c","https://git.kernel.org/stable/c/e7600f5cee5de14065f950807931d6e6d40fb2d7"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89741.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89741","state":"PUBLISHED","datePublished":"2026-09-11T19:46:47.877Z","dateUpdated":"2026-10-19T08:51:55.196Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.761Z"},"containers":{"cna":{"title":"Revert \"media: v4l2-dev: fix error handling in __video_register_device()\"","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"media: v4l2-dev: fix error handling in __video_register_device()\"\n\nThis reverts commit 2a934fdb01db6458288fc9386d3d8ceba6dd551a.\n\nThe intentions of that patch were good, but it doesn't work.\n\nThe idea is that if device_register fails, you have to do a put_device\nto let the ref counter release resources.\n\nHowever, the V4L2 API says that if video_register_device() fails, then\nyou have to call video_device_release(), which kfree()s the video_device\nstruct.\n\nBut the put_device() will already have freed the struct, so you end\nup in a double-free scenario.\n\nThere is not really a good way of fixing this without breaking\nvideo_register_device() into two parts, one that initializes everything,\nand one that does the actual device_register, and then converting all\nV4L2 drivers to this new model.\n\nThat is a massive job, and it is very unlikely that device_register\nwill fail.\n\nSo rather than ending up in a double-free scenario, just revert this\npatch, and in that case we'll have a small memory leak. Which is a lot\nmore robust."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e5c8e62ae551e0ad2e15412aa0c57c2856d59677","status":"affected","lessThan":"8b998c171ed875e402e1fd1c5cd619e4ca05e9c1","versionType":"git"},{"version":"8b451a9a46f2bfc510e6d5c2492df91647586184","status":"affected","lessThan":"3de14b4f681a1b3c6d375d98d9d37a55ebb85349","versionType":"git"},{"version":"b6be1f5633eae200af2527e9eeb7f51be5739b0f","status":"affected","lessThan":"8027f82c0f5474ed72448e160ee9778051fa1f49","versionType":"git"},{"version":"ae7b143e05b36fc69d6571751855946cc45064c6","status":"affected","lessThan":"2ac009a65d2385e9f0799eaf9d9694a29153a161","versionType":"git"},{"version":"2429bb9fad88c8fa84c4956b0a21cf5afe5e92b7","status":"affected","lessThan":"712ca1cf756de2557a116e0df55791bac0c9f99e","versionType":"git"},{"version":"2a934fdb01db6458288fc9386d3d8ceba6dd551a","status":"affected","lessThan":"aad08b5f67d2a8116e1a00bce2611c1513b10bce","versionType":"git"},{"version":"2a934fdb01db6458288fc9386d3d8ceba6dd551a","status":"affected","lessThan":"ce792b94e03882108019ba996c1a7c4d4e09be2c","versionType":"git"},{"version":"2a934fdb01db6458288fc9386d3d8ceba6dd551a","status":"affected","lessThan":"e7600f5cee5de14065f950807931d6e6d40fb2d7","versionType":"git"},{"version":"ee141706e701356dda41c6fed9ee18bf427c28e3","status":"affected","versionType":"git"},{"version":"4451412739ed33a49b34624299394ee575116d0c","status":"affected","versionType":"git"},{"version":"5.10.239","status":"affected","lessThan":"5.10.270","versionType":"semver"},{"version":"5.15.186","status":"affected","lessThan":"5.15.221","versionType":"semver"},{"version":"6.1.142","status":"affected","lessThan":"6.1.188","versionType":"semver"},{"version":"6.6.95","status":"affected","lessThan":"6.6.157","versionType":"semver"},{"version":"6.12.35","status":"affected","lessThan":"6.12.109","versionType":"semver"},{"version":"5.4.295","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"6.15.4","status":"affected","lessThan":"6.16","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/media/v4l2-core/v4l2-dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","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":["drivers/media/v4l2-core/v4l2-dev.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/8b998c171ed875e402e1fd1c5cd619e4ca05e9c1"},{"url":"https://git.kernel.org/stable/c/3de14b4f681a1b3c6d375d98d9d37a55ebb85349"},{"url":"https://git.kernel.org/stable/c/8027f82c0f5474ed72448e160ee9778051fa1f49"},{"url":"https://git.kernel.org/stable/c/2ac009a65d2385e9f0799eaf9d9694a29153a161"},{"url":"https://git.kernel.org/stable/c/712ca1cf756de2557a116e0df55791bac0c9f99e"},{"url":"https://git.kernel.org/stable/c/aad08b5f67d2a8116e1a00bce2611c1513b10bce"},{"url":"https://git.kernel.org/stable/c/ce792b94e03882108019ba996c1a7c4d4e09be2c"},{"url":"https://git.kernel.org/stable/c/e7600f5cee5de14065f950807931d6e6d40fb2d7"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The double-free is in __video_register_device(), reached from local V4L2 registration such as USB gadget UVC configfs UDC bind (uvc_function_bind → uvc_register_video) and usbfs/sysfs re-probe of USB cameras; dummy_hcd suffices and there is no remote packet path.\nAC:L - A local attacker can retry gadget bind or device re-probe under memory/resource pressure to make device_register() fail and take the put_device() error path; success does not depend on a victim-owned race or uninfluenced layout.\nPR:L - __video_register_device() and uvc_function_bind() perform no capable() check; Android/embedded HALs routinely delegate usb_gadget configfs to non-root, and desktop usbfs/video nodes are typically uaccess/video-group, so init-namespace root is not required.\nUI:N - The attacker performs the configfs UDC bind or local re-probe and applies resource pressure themselves; no separate victim mount, file-open, or cable-plug action is required.\nS:U - The heap double-free corrupts a kmalloc'd video_device or the parent object freed by vdev->release() inside the same host kernel security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - On device_register() failure the buggy put_device() runs v4l2_device_release() which calls vdev->release()/kfree, then callers such as video_device_release() or gspca/uvc probe error paths free the same object again, yielding a UAF disclosure primitive.\nI:H - The same double-free of struct video_device (or parent driver objects via vdev->release, as in UVC kref_put/uvc_delete and gspca_release) is heap corruption that can be sprayed into an arbitrary write and control-flow hijack.\nA:H - The double-free and premature v4l2_device_release() (including media_devnode_remove() on a still-NULL intf_devnode) oops or panic the kernel, and the attacker can repeat failed registration to force the crash."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:51:55.196Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.239","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.186","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.142","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.95","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.35","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.2.4"},{"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":"5.4.295"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15.4"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}