{"id":"DEBIAN-CVE-2022-48921","details":"In the Linux kernel, the following vulnerability has been resolved:  sched/fair: Fix fault in reweight_entity  Syzbot found a GPF in reweight_entity. This has been bisected to commit 4ef0c5c6b5ba (\"kernel/sched: Fix sched_fork() access an invalid sched_task_group\")  There is a race between sched_post_fork() and setpriority(PRIO_PGRP) within a thread group that causes a null-ptr-deref in reweight_entity() in CFS. The scenario is that the main process spawns number of new threads, which then call setpriority(PRIO_PGRP, 0, -20), wait, and exit.  For each of the new threads the copy_process() gets invoked, which adds the new task_struct and calls sched_post_fork() for it.  In the above scenario there is a possibility that setpriority(PRIO_PGRP) and set_one_prio() will be called for a thread in the group that is just being created by copy_process(), and for which the sched_post_fork() has not been executed yet. This will trigger a null pointer dereference in reweight_entity(), as it will try to access the run queue pointer, which hasn't been set.  Before the mentioned change the cfs_rq pointer for the task  has been set in sched_fork(), which is called much earlier in copy_process(), before the new task is added to the thread_group.  Now it is done in the sched_post_fork(), which is called after that.  To fix the issue the remove the update_load param from the update_load param() function and call reweight_task() only if the task flag doesn't have the TASK_NEW flag set.","modified":"2026-09-01T16:05:29.364993495Z","published":"2024-08-22T02:15:08.197Z","upstream":["CVE-2022-48921"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-48921"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.14-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-48921.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.14-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-48921.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.14-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-48921.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"}]}