CVE-2026-31458 | BDVDB-2026-328360 Detail
LinuxLinux
Description#
In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0] Multiple sysfs command paths dereference contexts_arr[0] without first verifying that kdamond->contexts->nr == 1. A user can set nr_contexts to 0 via sysfs while DAMON is running, causing NULL pointer dereferences. In more detail, the issue can be triggered by privileged users like below. First, start DAMON and make contexts directory empty (kdamond->contexts->nr == 0). # damo start # cd /sys/kernel/mm/damon/admin/kdamonds/0 # echo 0 > contexts/nr_contexts Then, each of below commands will cause the NULL pointer dereference. # echo update_schemes_stats > state # echo update_schemes_tried_regions > state # echo update_schemes_tried_bytes > state # echo update_schemes_effective_quotas > state # echo update_tuned_intervals > state Guard all commands (except OFF) at the entry point of damon_sysfs_handle_cmd().
Impact#
No impact statement in the source data.
Weaknesses#
No weakness recorded in the source data.
References#
- https://git.kernel.org/stable/c/aba546061341b56e9ffb37e1eb661a3628b6ec12
- https://git.kernel.org/stable/c/1e8da792672481d603fa7cd0d815577220a3ee27
- https://git.kernel.org/stable/c/708033c231bd782858f4ddbb46ee874a5a5fbdab
- https://git.kernel.org/stable/c/bbe03ad3fb9e714191757ca7b41582f930be7be2
- https://git.kernel.org/stable/c/1bfe9fb5ed2667fb075682408b776b5273162615
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.