{"id":"CVE-2026-53197","state":"PUBLISHED","title":"xfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()\n\niptfs_destroy_state() calls hrtimer_cancel() while holding a spinlock\nthat the timer callback also acquires, leading to an ABBA deadlock on\nSMP systems.\n\nFor the output timer (iptfs_timer):\n  - iptfs_destroy_state() holds x->lock, calls hrtimer_cancel()\n  - iptfs_delay_timer() callback takes x->lock\n\nFor the drop timer (drop_timer):\n  - iptfs_destroy_state() holds drop_lock, calls hrtimer_cancel()\n  - iptfs_drop_timer() callback takes drop_lock\n\nBoth timers use HRTIMER_MODE_REL_SOFT, so their callbacks run in softirq\ncontext.  When hrtimer_cancel() is called for a soft timer that is\ncurrently executing on another CPU, hrtimer_cancel_wait_running() spins\non softirq_expiry_lock -- the same lock held by the softirq running the\ncallback.  If the callback is blocked waiting for the spinlock held by\nthe caller of hrtimer_cancel(), a circular dependency forms:\n\n  CPU 0: holds lock_A -> waits for softirq_expiry_lock\n  CPU 1: holds softirq_expiry_lock -> waits for lock_A\n\nFix by calling hrtimer_cancel() before acquiring the respective locks.\nhrtimer_cancel() is safe to call without holding any lock and will wait\nfor any in-progress callback to complete.  For the output timer, the\nlock is still acquired afterwards to drain the packet queue.  For the\ndrop timer, the lock/unlock pair is removed entirely since it only\nexisted to serialize with the timer callback, which hrtimer_cancel()\nalready guarantees.\n\nFound by source code audit.","publishedAt":"2026-06-25T08:39:06.991Z","updatedAt":"2026-06-25T08:39:06.991Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4b3faf610cc63bfac972711635eafbca5e7d7117","status":"affected","lessThan":"a13ca53e47e500854a3b9ec18b5dc83acfec863e","versionType":"git"},{"version":"4b3faf610cc63bfac972711635eafbca5e7d7117","status":"affected","lessThan":"822b98d354e63e8249e85473c5f3c519f3c9cecc","versionType":"git"},{"version":"4b3faf610cc63bfac972711635eafbca5e7d7117","status":"affected","lessThan":"c8a8a75b733467b00c08b91a38dbaf207a08ed6e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_iptfs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","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":["net/xfrm/xfrm_iptfs.c"]}],"references":["https://git.kernel.org/stable/c/a13ca53e47e500854a3b9ec18b5dc83acfec863e","https://git.kernel.org/stable/c/822b98d354e63e8249e85473c5f3c519f3c9cecc","https://git.kernel.org/stable/c/c8a8a75b733467b00c08b91a38dbaf207a08ed6e"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53197.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53197","state":"PUBLISHED","datePublished":"2026-06-25T08:39:06.991Z","dateUpdated":"2026-06-25T08:39:06.991Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.391Z"},"containers":{"cna":{"title":"xfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()\n\niptfs_destroy_state() calls hrtimer_cancel() while holding a spinlock\nthat the timer callback also acquires, leading to an ABBA deadlock on\nSMP systems.\n\nFor the output timer (iptfs_timer):\n  - iptfs_destroy_state() holds x->lock, calls hrtimer_cancel()\n  - iptfs_delay_timer() callback takes x->lock\n\nFor the drop timer (drop_timer):\n  - iptfs_destroy_state() holds drop_lock, calls hrtimer_cancel()\n  - iptfs_drop_timer() callback takes drop_lock\n\nBoth timers use HRTIMER_MODE_REL_SOFT, so their callbacks run in softirq\ncontext.  When hrtimer_cancel() is called for a soft timer that is\ncurrently executing on another CPU, hrtimer_cancel_wait_running() spins\non softirq_expiry_lock -- the same lock held by the softirq running the\ncallback.  If the callback is blocked waiting for the spinlock held by\nthe caller of hrtimer_cancel(), a circular dependency forms:\n\n  CPU 0: holds lock_A -> waits for softirq_expiry_lock\n  CPU 1: holds softirq_expiry_lock -> waits for lock_A\n\nFix by calling hrtimer_cancel() before acquiring the respective locks.\nhrtimer_cancel() is safe to call without holding any lock and will wait\nfor any in-progress callback to complete.  For the output timer, the\nlock is still acquired afterwards to drain the packet queue.  For the\ndrop timer, the lock/unlock pair is removed entirely since it only\nexisted to serialize with the timer callback, which hrtimer_cancel()\nalready guarantees.\n\nFound by source code audit."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4b3faf610cc63bfac972711635eafbca5e7d7117","status":"affected","lessThan":"a13ca53e47e500854a3b9ec18b5dc83acfec863e","versionType":"git"},{"version":"4b3faf610cc63bfac972711635eafbca5e7d7117","status":"affected","lessThan":"822b98d354e63e8249e85473c5f3c519f3c9cecc","versionType":"git"},{"version":"4b3faf610cc63bfac972711635eafbca5e7d7117","status":"affected","lessThan":"c8a8a75b733467b00c08b91a38dbaf207a08ed6e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_iptfs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","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":["net/xfrm/xfrm_iptfs.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/a13ca53e47e500854a3b9ec18b5dc83acfec863e"},{"url":"https://git.kernel.org/stable/c/822b98d354e63e8249e85473c5f3c519f3c9cecc"},{"url":"https://git.kernel.org/stable/c/c8a8a75b733467b00c08b91a38dbaf207a08ed6e"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-06-25T08:39:06.991Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.0.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}