{"id":"CVE-2026-53197","summary":"xfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()","details":"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-\u003elock, calls hrtimer_cancel()\n  - iptfs_delay_timer() callback takes x-\u003elock\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 -\u003e waits for softirq_expiry_lock\n  CPU 1: holds softirq_expiry_lock -\u003e 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.","modified":"2026-07-08T08:13:43.162718536Z","published":"2026-06-25T08:39:06.991Z","related":["CGA-j3f9-x2jc-qq4g"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53197.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/822b98d354e63e8249e85473c5f3c519f3c9cecc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a13ca53e47e500854a3b9ec18b5dc83acfec863e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c8a8a75b733467b00c08b91a38dbaf207a08ed6e"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53197.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53197"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"4b3faf610cc63bfac972711635eafbca5e7d7117"},{"fixed":"a13ca53e47e500854a3b9ec18b5dc83acfec863e"},{"fixed":"822b98d354e63e8249e85473c5f3c519f3c9cecc"},{"fixed":"c8a8a75b733467b00c08b91a38dbaf207a08ed6e"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53197.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.14.0"},{"fixed":"6.18.36"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.13"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53197.json"}}],"schema_version":"1.7.5"}