{"id":"DEBIAN-CVE-2026-64458","details":"In the Linux kernel, the following vulnerability has been resolved:  mm/damon/ops-common: handle extreme intervals in damon_hot_score()  Fix three issues in damon_hot_score() that comes from wrong handling of extreme (zero or too high) monitoring intervals user setup.  When the user sets sampling interval zero, damon_max_nr_accesses(), which is called from damon_hot_score(), causes a divide-by-zero.  Needless to say, it is a problem.  When the user sets the aggregation interval zero, the function returns zero.  It is wrong, since the real maximum nr_acceses in the setup should be one.  Worse yet, it can cause another divide-by-zero from its caller, damon_hot_score(), since it uses damon_max_nr_accesses() return value as a denominator.  When the user sets the aggregation interval very high, damon_hot_score() could return a value out of [0, DAMOS_MAX_SCORE] range.  Since the return value is used as an index to the regions_score_histogram array, which is DAMOS_MAX_SCORE+1 size, it causes out of bounds array access.  The issues can be relatively easily reproduced like below.  The sysfs write permission is required, though.      # ./damo start --damos_action lru_prio --damos_quota_space 100M \\             --damos_quota_interval 1s     # cd /sys/kernel/mm/damon/admin/kdamonds/0     # echo 0 \u003e contexts/0/monitoring_attrs/intervals/sample_us     # echo 0 \u003e contexts/0/monitoring_attrs/intervals/aggr_us     # echo commit \u003e state     # dmesg     [...]     [  131.329762] Oops: divide error: 0000 [#1] SMP NOPTI     [...]     [  131.336089] RIP: 0010:damon_hot_score+0x27/0xd0     [...]  Fix the divide-by-zero intervals problems by explicitly handling the zero intervals in damon_max_nr_accesses().  Fix the out-of-bound array access by applying [0, DAMOS_MAX_SCORE] bounds before returning from damon_hot_score().  The issue was discovered [1] by Sashiko.","modified":"2026-09-01T16:06:55.787590161Z","published":"2026-07-25T10:17:30.943Z","upstream":["CVE-2026-64458"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-64458"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.180-1"}]}],"versions":["6.1.106-1","6.1.106-2","6.1.106-3","6.1.112-1","6.1.115-1","6.1.119-1","6.1.123-1","6.1.124-1","6.1.128-1","6.1.129-1","6.1.133-1","6.1.135-1","6.1.137-1","6.1.139-1","6.1.140-1","6.1.147-1","6.1.148-1","6.1.153-1","6.1.158-1","6.1.159-1","6.1.162-1","6.1.164-1","6.1.170-1","6.1.170-2","6.1.170-3","6.1.172-1","6.1.174-1","6.1.176-1","6.1.177-1","6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1","6.1.90-1~bpo11+1","6.1.94-1","6.1.94-1~bpo11+1","6.1.98-1","6.1.99-1"],"ecosystem_specific":{"urgency":"not 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