{"id":"CVE-2026-46065","state":"PUBLISHED","title":"fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info\n\nHold state of deferred I/O in struct fb_deferred_io_state. Allocate an\ninstance as part of initializing deferred I/O and remove it only after\nthe final mapping has been closed. If the fb_info and the contained\ndeferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info\nto invalidate the mapping. Any access will then result in a SIGBUS\nsignal.\n\nFixes a long-standing problem, where a device hot-unplug happens while\nuser space still has an active mapping of the graphics memory. The hot-\nunplug frees the instance of struct fb_info. Accessing the memory will\noperate on undefined state.","publishedAt":"2026-05-27T12:57:32.968Z","updatedAt":"2026-10-19T19:26:42.635Z","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":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"4aab89603b637a2e441b38808c4f6fe7d1184df6","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"4fda0d6b45faad44926dd3e4f55f118d899b2e27","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"2a40f8bc9bb713329f1c35ffc199ee961a7135b0","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"2b53d3a52e8e5403a4f4fb57ac6cad3fd2cb1066","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"25c2b77bc463f29ee71a54b883548baf9386a0db","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"a0aafb421dd15e935d81543152617f2742cefa70","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"9ded47ad003f09a94b6a710b5c47f4aa5ceb7429","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/video/fbdev/core/fb_defio.c","include/linux/fb.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.22","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.22","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.140","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.88","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.30","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.4","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/video/fbdev/core/fb_defio.c","include/linux/fb.h"]}],"references":["https://git.kernel.org/stable/c/4aab89603b637a2e441b38808c4f6fe7d1184df6","https://git.kernel.org/stable/c/4fda0d6b45faad44926dd3e4f55f118d899b2e27","https://git.kernel.org/stable/c/2a40f8bc9bb713329f1c35ffc199ee961a7135b0","https://git.kernel.org/stable/c/2b53d3a52e8e5403a4f4fb57ac6cad3fd2cb1066","https://git.kernel.org/stable/c/25c2b77bc463f29ee71a54b883548baf9386a0db","https://git.kernel.org/stable/c/a0aafb421dd15e935d81543152617f2742cefa70","https://git.kernel.org/stable/c/9ded47ad003f09a94b6a710b5c47f4aa5ceb7429","https://cert-portal.siemens.com/productcert/html/ssa-784472.html"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46065.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46065","state":"PUBLISHED","datePublished":"2026-05-27T12:57:32.968Z","dateUpdated":"2026-10-19T19:26:42.635Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.095Z"},"containers":{"cna":{"title":"fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info\n\nHold state of deferred I/O in struct fb_deferred_io_state. Allocate an\ninstance as part of initializing deferred I/O and remove it only after\nthe final mapping has been closed. If the fb_info and the contained\ndeferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info\nto invalidate the mapping. Any access will then result in a SIGBUS\nsignal.\n\nFixes a long-standing problem, where a device hot-unplug happens while\nuser space still has an active mapping of the graphics memory. The hot-\nunplug frees the instance of struct fb_info. Accessing the memory will\noperate on undefined state."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"4aab89603b637a2e441b38808c4f6fe7d1184df6","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"4fda0d6b45faad44926dd3e4f55f118d899b2e27","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"2a40f8bc9bb713329f1c35ffc199ee961a7135b0","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"2b53d3a52e8e5403a4f4fb57ac6cad3fd2cb1066","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"25c2b77bc463f29ee71a54b883548baf9386a0db","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"a0aafb421dd15e935d81543152617f2742cefa70","versionType":"git"},{"version":"60b59beafba875aef6d378078bce0baf2287ae14","status":"affected","lessThan":"9ded47ad003f09a94b6a710b5c47f4aa5ceb7429","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/video/fbdev/core/fb_defio.c","include/linux/fb.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.22","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.22","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.140","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.88","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.30","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.4","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/video/fbdev/core/fb_defio.c","include/linux/fb.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/4aab89603b637a2e441b38808c4f6fe7d1184df6"},{"url":"https://git.kernel.org/stable/c/4fda0d6b45faad44926dd3e4f55f118d899b2e27"},{"url":"https://git.kernel.org/stable/c/2a40f8bc9bb713329f1c35ffc199ee961a7135b0"},{"url":"https://git.kernel.org/stable/c/2b53d3a52e8e5403a4f4fb57ac6cad3fd2cb1066"},{"url":"https://git.kernel.org/stable/c/25c2b77bc463f29ee71a54b883548baf9386a0db"},{"url":"https://git.kernel.org/stable/c/a0aafb421dd15e935d81543152617f2742cefa70"},{"url":"https://git.kernel.org/stable/c/9ded47ad003f09a94b6a710b5c47f4aa5ceb7429"}],"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 vulnerable fault handlers are reached by mmap'ing /dev/fbN and accessing the mapping — a local operation requiring no network. Device removal (the precondition) can be non-physical (VM host-driven removal, sysfs unbind, module unload), so Local is the most severe defensible vector over Physical.\nAC:L - Once the device is removed while a mapping is active, any access deterministically hits the freed defio state/video pages — no race must be won to trigger it. In a kiosk/embedded scenario with a removable display the attacker controls both the mapping and the removal, and heap reclaim is attacker-influenced.\nPR:L - Exploitation requires only a local user with access to the framebuffer device, which is granted to the logged-in/console user, video-group members, Android apps, and is often world-accessible on embedded/kiosk systems. No root or init-namespace privilege is needed.\nUI:N - The attacker performs all steps themselves — map the framebuffer, cause/await removal, then access the mapping — with no separate victim action required.\nS:U - The use-after-free corrupts kernel memory within the same security authority; even in the VM-framebuffer case the impact stays inside the guest kernel and does not cross into the hypervisor.\nC:H - The fault handler returns freed-and-reclaimed video pages and the freed pagerefs array to userspace, allowing disclosure of arbitrary reallocated kernel/user memory — a use-after-free read primitive.\nI:H - The write-fault path writes a page pointer and offset into the kvfree'd pagerefs array and exposes freed/reallocated pages for writing, giving a use-after-free write primitive usable for control-flow hijacking via heap spraying.\nA:H - Accessing the mapping after teardown uses a destroyed mutex, freed pagerefs, and hits BUG_ON(!info->fbdefio->mapping), reliably causing an oops/panic; any use-after-free crashes the kernel."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:29:27.785Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"5.15.210"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"6.6.140"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"6.12.88"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"6.18.30"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"7.0.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.22","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 TM MFP - GNU/Linux subsystem","defaultStatus":"unknown","versions":[{"version":"0","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:20:19.593Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-46065","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:19:22.528676Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:26:42.635Z"}}]}}}