{"id":"DEBIAN-CVE-2026-46025","details":"In the Linux kernel, the following vulnerability has been resolved:  mm/damon/core: fix damon_call() vs kdamond_fn() exit race  Patch series \"mm/damon/core: fix damon_call()/damos_walk() vs kdmond exit race\".  damon_call() and damos_walk() can leak memory and/or deadlock when they race with kdamond terminations.  Fix those.   This patch (of 2);  When kdamond_fn() main loop is finished, the function cancels all remaining damon_call() requests and unset the damon_ctx-\u003ekdamond so that API callers and API functions themselves can know the context is terminated.  damon_call() adds the caller's request to the queue first.  After that, it shows if the kdamond of the damon_ctx is still running (damon_ctx-\u003ekdamond is set).  Only if the kdamond is running, damon_call() starts waiting for the kdamond's handling of the newly added request.  The damon_call() requests registration and damon_ctx-\u003ekdamond unset are protected by different mutexes, though.  Hence, damon_call() could race with damon_ctx-\u003ekdamond unset, and result in deadlocks.  For example, let's suppose kdamond successfully finished the damon_call() requests cancelling.  Right after that, damon_call() is called for the context.  It registers the new request, and shows the context is still running, because damon_ctx-\u003ekdamond unset is not yet done.  Hence the damon_call() caller starts waiting for the handling of the request.  However, the kdamond is already on the termination steps, so it never handles the new request.  As a result, the damon_call() caller threads infinitely waits.  Fix this by introducing another damon_ctx field, namely call_controls_obsolete.  It is protected by the damon_ctx-\u003ecall_controls_lock, which protects damon_call() requests registration.  Initialize (unset) it in kdamond_fn() before letting damon_start() returns and set it just before the cancelling of remaining damon_call() requests is executed.  damon_call() reads the obsolete field under the lock and avoids adding a new request.  After this change, only requests that are guaranteed to be handled or cancelled are registered.  Hence the after-registration DAMON context termination check is no longer needed.  Remove it together.  Note that the deadlock will not happen when damon_call() is called for repeat mode request.  In tis case, damon_call() returns instead of waiting for the handling when the request registration succeeds and it shows the kdamond is running.  However, if the request also has dealloc_on_cancel, the request memory would be leaked.  The issue is found by sashiko [1].","modified":"2026-08-27T23:06:26.663604189Z","published":"2026-05-27T14:17:21.013Z","upstream":["CVE-2026-46025"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-46025"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.0.4-1"}]}],"versions":["6.12.100-1","6.12.101-1","6.12.105-1","6.12.38-1","6.12.41-1","6.12.43-1","6.12.43-1~bpo12+1","6.12.48-1","6.12.57-1","6.12.57-1~bpo12+1","6.12.63-1","6.12.63-1~bpo12+1","6.12.69-1","6.12.69-1~bpo12+1","6.12.73-1","6.12.73-1~bpo12+1","6.12.74-1","6.12.74-2","6.12.74-2~bpo12+1","6.12.85-1","6.12.85-1~bpo12+1","6.12.86-1","6.12.86-1~bpo12+1","6.12.88-1","6.12.88-1~bpo12+1","6.12.90-1","6.12.90-1~bpo12+1","6.12.90-2","6.12.90-2~bpo12+1","6.12.94-1","6.12.94-1~bpo12+1","6.12.95-1","6.12.95-1~bpo12+1","6.12.96-1","6.13.10-1~exp1","6.13.11-1~exp1","6.13.2-1~exp1","6.13.3-1~exp1","6.13.4-1~exp1","6.13.5-1~exp1","6.13.6-1~exp1","6.13.7-1~exp1","6.13.8-1~exp1","6.13.9-1~exp1","6.13~rc6-1~exp1","6.13~rc7-1~exp1","6.14.3-1~exp1","6.14.5-1~exp1","6.14.6-1~exp1","6.15-1~exp1","6.15.1-1~exp1","6.15.2-1~exp1","6.15.3-1~exp1","6.15.4-1~exp1","6.15.5-1~exp1","6.15.6-1~exp1","6.15~rc7-1~exp1","6.16-1~exp1","6.16.1-1~exp1","6.16.10-1","6.16.11-1","6.16.12-1","6.16.12-1~bpo13+1","6.16.12-2","6.16.3-1","6.16.3-1~bpo13+1","6.16.5-1","6.16.6-1","6.16.7-1","6.16.8-1","6.16.9-1","6.16~rc7-1~exp1","6.17.10-1","6.17.11-1","6.17.12-1","6.17.13-1","6.17.13-1~bpo13+1","6.17.2-1~exp1","6.17.5-1~exp1","6.17.6-1","6.17.7-1","6.17.7-2","6.17.8-1","6.17.8-1~bpo13+1","6.17.9-1","6.18.1-1~exp1","6.18.10-1","6.18.12-1","6.18.12-1~bpo13+1","6.18.13-1","6.18.14-1","6.18.15-1","6.18.15-1~bpo13+1","6.18.2-1~exp1","6.18.3-1","6.18.5-1","6.18.5-1~bpo13+1","6.18.8-1","6.18.9-1","6.18.9-1~bpo13+1","6.18~rc4-1~exp1","6.18~rc4-1~exp2","6.18~rc5-1~exp1","6.18~rc6-1~exp1","6.18~rc7-1~exp1","6.19-1~exp1","6.19.10-1","6.19.10-1~bpo13+1","6.19.11-1","6.19.11-1~bpo13+1","6.19.12-1","6.19.13-1","6.19.13-1~bpo13+1","6.19.14-1","6.19.14-1~bpo13+1","6.19.2-1~exp1","6.19.3-1~exp1","6.19.4-1~exp1","6.19.5-1~exp1","6.19.6-1","6.19.6-2","6.19.6-2~bpo13+1","6.19.8-1","6.19.8-1~bpo13+1","6.19~rc4-1~exp1","6.19~rc5-1~exp1","6.19~rc6-1~exp1","6.19~rc7-1~exp1","6.19~rc8-1~exp1","7.0-1~exp1","7.0.1-1~exp1","7.0.3-1","7.0.4-1~bpo13+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-46025.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}