cbcvebase.
CVE-2025-39780
published 2025-09-11

CVE-2025-39780: In the Linux kernel, the following vulnerability has been resolved: sched/ext: Fix invalid task state transitions on class switch When enabling a sched_ext…

PriorityP418medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.14%
3.9th percentile
In the Linux kernel, the following vulnerability has been resolved: sched/ext: Fix invalid task state transitions on class switch When enabling a sched_ext scheduler, we may trigger invalid task state transitions, resulting in warnings like the following (which can be easily reproduced by running the hotplug selftest in a loop): sched_ext: Invalid task state transition 0 -> 3 for fish[770] WARNING: CPU: 18 PID: 787 at kernel/sched/ext.c:3862 scx_set_task_state+0x7c/0xc0 ... RIP: 0010:scx_set_task_state+0x7c/0xc0 ... Call Trace: scx_enable_task+0x11f/0x2e0 switching_to_scx+0x24/0x110 scx_enable.isra.0+0xd14/0x13d0 bpf_struct_ops_link_create+0x136/0x1a0 __sys_bpf+0x1edd/0x2c30 __x64_sys_bpf+0x21/0x30 do_syscall_64+0xbb/0x370 entry_SYSCALL_64_after_hwframe+0x77/0x7f This happens because we skip initialization for tasks that are already dead (with their usage counter set to zero), but we don't exclude them during the scheduling class transition phase. Fix this by also skipping dead tasks during class swiching, preventing invalid task state transitions.

Affected

11 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.16.5-1 (forky)linux 6.16.5-1 (forky)
linuxlinux
linuxlinux>= a8532fac7b5d27b8d62008a89593dccb6f9786ef < 786f6314604b34c3e7de5f733f4e08e35c448a50786f6314604b34c3e7de5f733f4e08e35c448a50
linuxlinux>= a8532fac7b5d27b8d62008a89593dccb6f9786ef < 6a32cbe95029ebe21cc08349fd7ef2a3d32d20436a32cbe95029ebe21cc08349fd7ef2a3d32d2043
linuxlinux>= a8532fac7b5d27b8d62008a89593dccb6f9786ef < ddf7233fcab6c247379d0928d46cc316ee122229ddf7233fcab6c247379d0928d46cc316ee122229
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.48-16.12.48-1
linuxlinux_kernel>= 0 < 6.16.5-16.16.5-1
linuxlinux_kernel>= 6.12 < 6.12.446.12.44
linuxlinux_kernel>= 6.13 < 6.16.46.16.4

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
cisa8.8HIGH
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
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