{"id":"CVE-2026-93054","state":"PUBLISHED","title":"uio: Fix stale info pointer in failed registration path","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nuio: Fix stale info pointer in failed registration path\n\nAfter device_add(), the UIO device is visible to userspace and /dev/uioX\ncan be opened. If a later setup step fails, __uio_register_device()\nunwinds the device but leaves idev->info pointing at the caller-owned\nstruct uio_info.\n\nThat is unsafe when an opener races with the failed registration path.\nThe open file keeps a reference to the uio_device, while the caller sees\nregistration failure and may free its struct uio_info. Later file\noperations can then follow idev->info and dereference freed memory.\n\nHandle post-device_add() failures like unregister: remove UIO attributes\nwhile the info pointer is still valid, then clear idev->info under\ninfo_lock and wake existing waiters/async users before removing the\ndevice and minor. This makes already-open file descriptors observe the\nsame \"device gone\" state as normal uio_unregister_device().","publishedAt":"2026-09-17T16:10:43.104Z","updatedAt":"2026-10-19T09:04:49.183Z","severity":{"score":7,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/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":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"63eaa7663335d482a8825c231213e312cacea567","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"df4faf65194ec6c315a59be4c6749eaeb3009243","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"506b43dde5f9ac0068b1360e6b5dbee07fda59fb","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"15340b00e665af805523b08515294a1aa1778151","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"234156f6c6d9ec35dc47abbcc3adc3c79fc6a5ac","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"16695e9059d80ea6661e8399064b0c01f641dd8c","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"ec5bd6731183eb6f619140c9bef2ee11ed818c20","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"67b6fc084b034a91c3ec7907a3fed89a2450f30b","versionType":"git"},{"version":"085d735c858934e5d5bfaedb1fc98bd9135e6ff1","status":"affected","versionType":"git"},{"version":"4.14.100","status":"affected","lessThan":"4.15","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/uio/uio.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.18","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":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","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/uio/uio.c"]}],"references":["https://git.kernel.org/stable/c/63eaa7663335d482a8825c231213e312cacea567","https://git.kernel.org/stable/c/df4faf65194ec6c315a59be4c6749eaeb3009243","https://git.kernel.org/stable/c/506b43dde5f9ac0068b1360e6b5dbee07fda59fb","https://git.kernel.org/stable/c/15340b00e665af805523b08515294a1aa1778151","https://git.kernel.org/stable/c/234156f6c6d9ec35dc47abbcc3adc3c79fc6a5ac","https://git.kernel.org/stable/c/16695e9059d80ea6661e8399064b0c01f641dd8c","https://git.kernel.org/stable/c/ec5bd6731183eb6f619140c9bef2ee11ed818c20","https://git.kernel.org/stable/c/67b6fc084b034a91c3ec7907a3fed89a2450f30b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/93xxx/CVE-2026-93054.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-93054","state":"PUBLISHED","datePublished":"2026-09-17T16:10:43.104Z","dateUpdated":"2026-10-19T09:04:49.183Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-17T15:57:05.658Z"},"containers":{"cna":{"title":"uio: Fix stale info pointer in failed registration path","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nuio: Fix stale info pointer in failed registration path\n\nAfter device_add(), the UIO device is visible to userspace and /dev/uioX\ncan be opened. If a later setup step fails, __uio_register_device()\nunwinds the device but leaves idev->info pointing at the caller-owned\nstruct uio_info.\n\nThat is unsafe when an opener races with the failed registration path.\nThe open file keeps a reference to the uio_device, while the caller sees\nregistration failure and may free its struct uio_info. Later file\noperations can then follow idev->info and dereference freed memory.\n\nHandle post-device_add() failures like unregister: remove UIO attributes\nwhile the info pointer is still valid, then clear idev->info under\ninfo_lock and wake existing waiters/async users before removing the\ndevice and minor. This makes already-open file descriptors observe the\nsame \"device gone\" state as normal uio_unregister_device()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"63eaa7663335d482a8825c231213e312cacea567","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"df4faf65194ec6c315a59be4c6749eaeb3009243","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"506b43dde5f9ac0068b1360e6b5dbee07fda59fb","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"15340b00e665af805523b08515294a1aa1778151","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"234156f6c6d9ec35dc47abbcc3adc3c79fc6a5ac","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"16695e9059d80ea6661e8399064b0c01f641dd8c","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"ec5bd6731183eb6f619140c9bef2ee11ed818c20","versionType":"git"},{"version":"a93e7b331568227500186a465fee3c2cb5dffd1f","status":"affected","lessThan":"67b6fc084b034a91c3ec7907a3fed89a2450f30b","versionType":"git"},{"version":"085d735c858934e5d5bfaedb1fc98bd9135e6ff1","status":"affected","versionType":"git"},{"version":"4.14.100","status":"affected","lessThan":"4.15","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/uio/uio.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.18","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":"6.12.110","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","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/uio/uio.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/63eaa7663335d482a8825c231213e312cacea567"},{"url":"https://git.kernel.org/stable/c/df4faf65194ec6c315a59be4c6749eaeb3009243"},{"url":"https://git.kernel.org/stable/c/506b43dde5f9ac0068b1360e6b5dbee07fda59fb"},{"url":"https://git.kernel.org/stable/c/15340b00e665af805523b08515294a1aa1778151"},{"url":"https://git.kernel.org/stable/c/234156f6c6d9ec35dc47abbcc3adc3c79fc6a5ac"},{"url":"https://git.kernel.org/stable/c/16695e9059d80ea6661e8399064b0c01f641dd8c"},{"url":"https://git.kernel.org/stable/c/ec5bd6731183eb6f619140c9bef2ee11ed818c20"},{"url":"https://git.kernel.org/stable/c/67b6fc084b034a91c3ec7907a3fed89a2450f30b"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - After device_add() in __uio_register_device(), the char device is opened via open(2) on /dev/uioN into uio_open(); the dangling idev->info is then used by uio_write/uio_mmap/uio_release on that fd. Callers such as tcmu_configure_device() (configfs enable) and uio_pci_generic probe() register locally; no remote protocol carries the trigger.\nAC:H - The stale-info unwind runs only when uio_dev_add_attributes() (kobject_create_and_add/kobject_add/kobject_uevent for maps/portio) or request_threaded_irq() fails after device_add(). Those fail on -ENOMEM, kernfs errors, or IRQ setup failure the attacker cannot force; a successful register never leaves idev->info set after the caller drops struct uio_info.\nPR:L - uio_open() has no capable() check, and uio_pci_generic installs no info->open hook, so the racing open is gated only by /dev/uioN inode mode. Reasonable UIO deployments (DPDK udev, tcmu-runner) grant that node to a non-root account that can also write target_dev_enable_store (TCMU) or hold the fd across a failing probe.\nUI:N - The same actor can write target_dev_enable_store (echo 1 > enable -> tcmu_configure_device -> uio_register_device) or bind uio_pci_generic while another thread open()s /dev/uioN and then mmap/write/close; no other user must mount media or confirm a prompt.\nS:U - The use-after-free is idev->info in the host UIO core (uio_write/uio_mmap/uio_release) after the caller (e.g. devm unwind of uio_pci_generic's struct uio_pci_generic_dev) frees struct uio_info; impact stays in the host kernel, not a KVM/Xen, IOMMU, or sandbox escape.\nC:H - After the caller frees struct uio_info, uio_read and uio_mmap still treat the non-NULL idev->info as live and read info->irq, info->mem[], and related fields. Reclaiming that slab object gives an arbitrary kernel read through those file operations.\nI:H - uio_write() calls idev->info->irqcontrol, uio_open() calls info->open, and uio_release() calls info->release on the freed uio_info; uio_mmap_physical() feeds info->mem[].addr into remap_pfn_range(). Spraying the object hijacks those function pointers or the PFN map for an arbitrary write/CFI primitive.\nA:H - uio_write/uio_mmap/uio_release and uio_vma_fault dereference the freed idev->info (and TCMU's tcmu_vma_fault uses info->mem[].addr after vfree(mb_addr) on err_register), which oopses or panics the kernel even without a successful spray."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:04:49.183Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.18","versionEndExcluding":"7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14.100"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}