{"id":"CVE-2026-98826","state":"PUBLISHED","title":"rtc: ac100: Fix clock provider use-after-free on probe failure","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrtc: ac100: Fix clock provider use-after-free on probe failure\n\nac100_rtc_register_clks() registers the RTC-32k clock with\nclk_hw_register_fixed_rate() and the clock provider with\nof_clk_add_hw_provider(). Neither is device managed, and both are\nreleased only from ac100_rtc_remove(). The driver core does not call\nremove() when probe() fails: really_probe() reaches probe_failed below\nthe device_remove() call and goes straight to releasing the device's\nmanaged resources.\n\nac100_rtc_probe() ends with\n\n\treturn devm_rtc_register_device(chip->rtc);\n\nso if that fails after the clocks have been registered, the provider is\nleft on the global of_clk_providers list holding chip->clk_data, which\nwas allocated with devm_kzalloc() and is freed while probe() unwinds. A\nlater lookup on this device tree node then reads freed memory in\nof_clk_hw_onecell_get(). Consumers that do exactly that exist in tree:\nthe wifi power sequence nodes on sun8i-a83t-bananapi-m3 and\nsun8i-a83t-cubietruck-plus take <&ac100_rtc 1>, and the sun9i-a80 boards\nroute osc32k through <&ac100_rtc 0>. The window is narrow, as\ndevm_rtc_register_device() can only fail with -ENOMEM here, but the\nprovider is left dangling whenever it does.\n\nThe RTC-32k clock is leaked on the same path. Since clk_core_lookup()\nsearches a global list that is not scoped per device, __clk_register()\nrejects the duplicate name with -EEXIST, so the leak also makes a later\nprobe of the same device fail.\n\nThe error path that returns -EINVAL when the ADDA 4M parent clock cannot\nbe found leaks the RTC-32k clock in the same way. No provider has been\nregistered at that point, so that one is a leak rather than a\nuse-after-free.\n\nRegister both with devm_clk_hw_register_fixed_rate() and\ndevm_of_clk_add_hw_provider() so that they are released whenever the\ndevice goes away, on a failed probe as well as on unbind. Devres\nreleases in reverse order of acquisition, so the provider is removed\nbefore chip->clk_data is freed, and the clkout children are now\nunregistered before their parent rather than after it.\nac100_rtc_unregister_clks() and the remove callback then have nothing\nleft to do and are removed.","publishedAt":"2026-10-18T15:49:19.709Z","updatedAt":"2026-10-19T09:26:19.030Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d00a18a42c1483924de086ddfb0efe8da1dba3ac","status":"affected","lessThan":"12bcd20d76703ee2baf52224d287b7fea096b12f","versionType":"git"},{"version":"d00a18a42c1483924de086ddfb0efe8da1dba3ac","status":"affected","lessThan":"9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8","versionType":"git"},{"version":"d00a18a42c1483924de086ddfb0efe8da1dba3ac","status":"affected","lessThan":"55ca60ba336632349f7c4585d22ba74ae355b7ce","versionType":"git"},{"version":"d00a18a42c1483924de086ddfb0efe8da1dba3ac","status":"affected","lessThan":"fcf0b58e976e83adf246b014518e49c662b96f5e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/rtc/rtc-ac100.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.9","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","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/rtc/rtc-ac100.c"]}],"references":["https://git.kernel.org/stable/c/12bcd20d76703ee2baf52224d287b7fea096b12f","https://git.kernel.org/stable/c/9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8","https://git.kernel.org/stable/c/55ca60ba336632349f7c4585d22ba74ae355b7ce","https://git.kernel.org/stable/c/fcf0b58e976e83adf246b014518e49c662b96f5e"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98826.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98826","state":"PUBLISHED","datePublished":"2026-10-18T15:49:19.709Z","dateUpdated":"2026-10-19T09:26:19.030Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.372Z"},"containers":{"cna":{"title":"rtc: ac100: Fix clock provider use-after-free on probe failure","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrtc: ac100: Fix clock provider use-after-free on probe failure\n\nac100_rtc_register_clks() registers the RTC-32k clock with\nclk_hw_register_fixed_rate() and the clock provider with\nof_clk_add_hw_provider(). Neither is device managed, and both are\nreleased only from ac100_rtc_remove(). The driver core does not call\nremove() when probe() fails: really_probe() reaches probe_failed below\nthe device_remove() call and goes straight to releasing the device's\nmanaged resources.\n\nac100_rtc_probe() ends with\n\n\treturn devm_rtc_register_device(chip->rtc);\n\nso if that fails after the clocks have been registered, the provider is\nleft on the global of_clk_providers list holding chip->clk_data, which\nwas allocated with devm_kzalloc() and is freed while probe() unwinds. A\nlater lookup on this device tree node then reads freed memory in\nof_clk_hw_onecell_get(). Consumers that do exactly that exist in tree:\nthe wifi power sequence nodes on sun8i-a83t-bananapi-m3 and\nsun8i-a83t-cubietruck-plus take <&ac100_rtc 1>, and the sun9i-a80 boards\nroute osc32k through <&ac100_rtc 0>. The window is narrow, as\ndevm_rtc_register_device() can only fail with -ENOMEM here, but the\nprovider is left dangling whenever it does.\n\nThe RTC-32k clock is leaked on the same path. Since clk_core_lookup()\nsearches a global list that is not scoped per device, __clk_register()\nrejects the duplicate name with -EEXIST, so the leak also makes a later\nprobe of the same device fail.\n\nThe error path that returns -EINVAL when the ADDA 4M parent clock cannot\nbe found leaks the RTC-32k clock in the same way. No provider has been\nregistered at that point, so that one is a leak rather than a\nuse-after-free.\n\nRegister both with devm_clk_hw_register_fixed_rate() and\ndevm_of_clk_add_hw_provider() so that they are released whenever the\ndevice goes away, on a failed probe as well as on unbind. Devres\nreleases in reverse order of acquisition, so the provider is removed\nbefore chip->clk_data is freed, and the clkout children are now\nunregistered before their parent rather than after it.\nac100_rtc_unregister_clks() and the remove callback then have nothing\nleft to do and are removed."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d00a18a42c1483924de086ddfb0efe8da1dba3ac","status":"affected","lessThan":"12bcd20d76703ee2baf52224d287b7fea096b12f","versionType":"git"},{"version":"d00a18a42c1483924de086ddfb0efe8da1dba3ac","status":"affected","lessThan":"9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8","versionType":"git"},{"version":"d00a18a42c1483924de086ddfb0efe8da1dba3ac","status":"affected","lessThan":"55ca60ba336632349f7c4585d22ba74ae355b7ce","versionType":"git"},{"version":"d00a18a42c1483924de086ddfb0efe8da1dba3ac","status":"affected","lessThan":"fcf0b58e976e83adf246b014518e49c662b96f5e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/rtc/rtc-ac100.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.9","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","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/rtc/rtc-ac100.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/12bcd20d76703ee2baf52224d287b7fea096b12f"},{"url":"https://git.kernel.org/stable/c/9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8"},{"url":"https://git.kernel.org/stable/c/55ca60ba336632349f7c4585d22ba74ae355b7ce"},{"url":"https://git.kernel.org/stable/c/fcf0b58e976e83adf246b014518e49c662b96f5e"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:26:19.030Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}