{"affected":[{"defaultStatus":"unaffected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"lessThan":"5d217e7031a5c06d366580fc6ddbf43527b780d4","status":"affected","version":"73f37068d540eba5f93ba3a0019bf479d35ebd76","versionType":"git"},{"lessThan":"b1b73c452331451020be3bf4b014901015ae6663","status":"affected","version":"73f37068d540eba5f93ba3a0019bf479d35ebd76","versionType":"git"},{"lessThan":"259119595227fd20f6aa29d85abe086b6fdd9eb1","status":"affected","version":"73f37068d540eba5f93ba3a0019bf479d35ebd76","versionType":"git"},{"lessThan":"b93e6fef4eda48e17d9c642b9abad98a066fd4a3","status":"affected","version":"73f37068d540eba5f93ba3a0019bf479d35ebd76","versionType":"git"},{"lessThan":"ef8fc007c28a30a4c0d90bf755e0f343d99bb392","status":"affected","version":"73f37068d540eba5f93ba3a0019bf479d35ebd76","versionType":"git"},{"lessThan":"87f7ce260a3c838b49e1dc1ceedf1006795157a2","status":"affected","version":"73f37068d540eba5f93ba3a0019bf479d35ebd76","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"status":"affected","version":"5.14"},{"lessThan":"5.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.186","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.142","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.94","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.34","versionType":"semver"},{"lessThanOrEqual":"6.15.*","status":"unaffected","version":"6.15.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.16","versionType":"original_commit_for_fix"}]}],"cveId":"CVE-2025-38305","cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nptp: remove ptp->n_vclocks check logic in ptp_vclock_in_use()\n\nThere is no disagreement that we should check both ptp->is_virtual_clock\nand ptp->n_vclocks to check if the ptp virtual clock is in use.\n\nHowever, when we acquire ptp->n_vclocks_mux to read ptp->n_vclocks in\nptp_vclock_in_use(), we observe a recursive lock in the call trace\nstarting from n_vclocks_store().\n\n============================================\nWARNING: possible recursive locking detected\n6.15.0-rc6 #1 Not tainted\n--------------------------------------------\nsyz.0.1540/13807 is trying to acquire lock:\nffff888035a24868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at:\n ptp_vclock_in_use drivers/ptp/ptp_private.h:103 [inline]\nffff888035a24868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at:\n ptp_clock_unregister+0x21/0x250 drivers/ptp/ptp_clock.c:415\n\nbut task is already holding lock:\nffff888030704868 (&ptp->n_vclocks_mux){+.+.}-{4:4}, at:\n n_vclocks_store+0xf1/0x6d0 drivers/ptp/ptp_sysfs.c:215\n\nother info that might help us debug this:\n Possible unsafe locking scenario:\n\n       CPU0\n       ----\n  lock(&ptp->n_vclocks_mux);\n  lock(&ptp->n_vclocks_mux);\n\n *** DEADLOCK ***\n....\n============================================\n\nThe best way to solve this is to remove the logic that checks\nptp->n_vclocks in ptp_vclock_in_use().\n\nThe reason why this is appropriate is that any path that uses\nptp->n_vclocks must unconditionally check if ptp->n_vclocks is greater\nthan 0 before unregistering vclocks, and all functions are already\nwritten this way. And in the function that uses ptp->n_vclocks, we\nalready get ptp->n_vclocks_mux before unregistering vclocks.\n\nTherefore, we need to remove the redundant check for ptp->n_vclocks in\nptp_vclock_in_use() to prevent recursive locking.","epss":{"date":"2026-11-05","percentile":0.07543,"score":0.00179},"exploits":[],"kev":null,"metrics":[],"modifiedAt":1793912551571,"publishedAt":1752133336127,"references":[{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/5d217e7031a5c06d366580fc6ddbf43527b780d4"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/b1b73c452331451020be3bf4b014901015ae6663"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/259119595227fd20f6aa29d85abe086b6fdd9eb1"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/b93e6fef4eda48e17d9c642b9abad98a066fd4a3"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/ef8fc007c28a30a4c0d90bf755e0f343d99bb392"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/87f7ce260a3c838b49e1dc1ceedf1006795157a2"},{"source":"ADP: CVE","tags":[],"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"}],"remediation":[],"revision":"5dda837988cbe5ba23f909ec7ca00075027dabb7e162708ac8a26ff324bc6ac2","sources":[{"modifiedAt":1793912551571,"name":"CNA: Linux","retrievedAt":1793913646396,"url":"https://www.cve.org/CVERecord?id=CVE-2025-38305"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793913671852,"url":"https://api.first.org/data/v1/epss?cve=CVE-2025-38305"}],"ssvc":{"assessedAt":1793912016196,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"ptp: remove ptp->n_vclocks check logic in ptp_vclock_in_use()","updatedAt":1793913671852}