{"id":"CVE-2026-23400","state":"PUBLISHED","title":"rust_binder: call set_notification_done() without proc lock","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrust_binder: call set_notification_done() without proc lock\n\nConsider the following sequence of events on a death listener:\n1. The remote process dies and sends a BR_DEAD_BINDER message.\n2. The local process invokes the BC_CLEAR_DEATH_NOTIFICATION command.\n3. The local process then invokes the BC_DEAD_BINDER_DONE.\nThen, the kernel will reply to the BC_DEAD_BINDER_DONE command with a\nBR_CLEAR_DEATH_NOTIFICATION_DONE reply using push_work_if_looper().\n\nHowever, this can result in a deadlock if the current thread is not a\nlooper. This is because dead_binder_done() still holds the proc lock\nduring set_notification_done(), which called push_work_if_looper().\nNormally, push_work_if_looper() takes the thread lock, which is fine to\ntake under the proc lock. But if the current thread is not a looper,\nthen it falls back to delivering the reply to the process work queue,\nwhich involves taking the proc lock. Since the proc lock is already\nheld, this is a deadlock.\n\nFix this by releasing the proc lock during set_notification_done(). It\nwas not intentional that it was held during that function to begin with.\n\nI don't think this ever happens in Android because BC_DEAD_BINDER_DONE\nis only invoked in response to BR_DEAD_BINDER messages, and the kernel\nalways delivers BR_DEAD_BINDER to a looper. So there's no scenario where\nAndroid userspace will call BC_DEAD_BINDER_DONE on a non-looper thread.","publishedAt":"2026-03-29T12:55:50.660Z","updatedAt":"2026-05-11T22:06:10.668Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"eafedbc7c050c44744fbdf80bdf3315e860b7513","status":"affected","lessThan":"dd109e3442817bc03ad1f3ffd541092f8c428141","versionType":"git"},{"version":"eafedbc7c050c44744fbdf80bdf3315e860b7513","status":"affected","lessThan":"3be72099067d2cd4a0e089696f19780f75b2b88a","versionType":"git"},{"version":"eafedbc7c050c44744fbdf80bdf3315e860b7513","status":"affected","lessThan":"2e303f0febb65a434040774b793ba8356698802b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/android/binder/process.rs"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.18","versionType":"semver"},{"version":"6.18.19","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/android/binder/process.rs"]}],"references":["https://git.kernel.org/stable/c/dd109e3442817bc03ad1f3ffd541092f8c428141","https://git.kernel.org/stable/c/3be72099067d2cd4a0e089696f19780f75b2b88a","https://git.kernel.org/stable/c/2e303f0febb65a434040774b793ba8356698802b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/23xxx/CVE-2026-23400.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23400","state":"PUBLISHED","datePublished":"2026-03-29T12:55:50.660Z","dateUpdated":"2026-05-11T22:06:10.668Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-01-13T15:37:46.012Z"},"containers":{"cna":{"title":"rust_binder: call set_notification_done() without proc lock","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrust_binder: call set_notification_done() without proc lock\n\nConsider the following sequence of events on a death listener:\n1. The remote process dies and sends a BR_DEAD_BINDER message.\n2. The local process invokes the BC_CLEAR_DEATH_NOTIFICATION command.\n3. The local process then invokes the BC_DEAD_BINDER_DONE.\nThen, the kernel will reply to the BC_DEAD_BINDER_DONE command with a\nBR_CLEAR_DEATH_NOTIFICATION_DONE reply using push_work_if_looper().\n\nHowever, this can result in a deadlock if the current thread is not a\nlooper. This is because dead_binder_done() still holds the proc lock\nduring set_notification_done(), which called push_work_if_looper().\nNormally, push_work_if_looper() takes the thread lock, which is fine to\ntake under the proc lock. But if the current thread is not a looper,\nthen it falls back to delivering the reply to the process work queue,\nwhich involves taking the proc lock. Since the proc lock is already\nheld, this is a deadlock.\n\nFix this by releasing the proc lock during set_notification_done(). It\nwas not intentional that it was held during that function to begin with.\n\nI don't think this ever happens in Android because BC_DEAD_BINDER_DONE\nis only invoked in response to BR_DEAD_BINDER messages, and the kernel\nalways delivers BR_DEAD_BINDER to a looper. So there's no scenario where\nAndroid userspace will call BC_DEAD_BINDER_DONE on a non-looper thread."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"eafedbc7c050c44744fbdf80bdf3315e860b7513","status":"affected","lessThan":"dd109e3442817bc03ad1f3ffd541092f8c428141","versionType":"git"},{"version":"eafedbc7c050c44744fbdf80bdf3315e860b7513","status":"affected","lessThan":"3be72099067d2cd4a0e089696f19780f75b2b88a","versionType":"git"},{"version":"eafedbc7c050c44744fbdf80bdf3315e860b7513","status":"affected","lessThan":"2e303f0febb65a434040774b793ba8356698802b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/android/binder/process.rs"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.18","versionType":"semver"},{"version":"6.18.19","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.9","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/android/binder/process.rs"]}],"references":[{"url":"https://git.kernel.org/stable/c/dd109e3442817bc03ad1f3ffd541092f8c428141"},{"url":"https://git.kernel.org/stable/c/3be72099067d2cd4a0e089696f19780f75b2b88a"},{"url":"https://git.kernel.org/stable/c/2e303f0febb65a434040774b793ba8356698802b"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T22:06:10.668Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"6.18.19"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"6.19.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}