CVE-2026-31457

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/damon/sysfs: check contexts-&gt;nr in repeat_call_fn<br /> <br /> damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(),<br /> damon_sysfs_upd_schemes_stats(), and<br /> damon_sysfs_upd_schemes_effective_quotas() without checking contexts-&gt;nr. <br /> If nr_contexts is set to 0 via sysfs while DAMON is running, these<br /> functions dereference contexts_arr[0] and cause a NULL pointer<br /> dereference. Add the missing check.<br /> <br /> For example, the issue can be reproduced using DAMON sysfs interface and<br /> DAMON user-space tool (damo) [1] like below.<br /> <br /> $ sudo damo start --refresh_interval 1s<br /> $ echo 0 | sudo tee \<br /> /sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts