syzbot


KMSAN: uninit-value in pick_task_fair

Status: upstream: reported on 2026/01/30 21:10
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+edaa9ae65c490cb55bf2@syzkaller.appspotmail.com
First crash: 13d, last: 13d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] KMSAN: uninit-value in pick_task_fair 0 (1) 2026/01/30 21:10
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in pick_task_fair net crypto 19 471 529d 538d 0/29 closed as invalid on 2024/09/13 10:29

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in pick_task_fair+0x29d/0x510 kernel/sched/fair.c:8890
 pick_task_fair+0x29d/0x510 kernel/sched/fair.c:8890
 pick_next_task_fair+0x120/0x2550 kernel/sched/fair.c:8918
 __pick_next_task+0x108/0x6e0 kernel/sched/core.c:5890
 pick_next_task kernel/sched/core.c:5983 [inline]
 __schedule+0xee5/0x8180 kernel/sched/core.c:6809
 __schedule_loop kernel/sched/core.c:6949 [inline]
 schedule+0x17c/0x3c0 kernel/sched/core.c:6964
 worker_thread+0x1b45/0x1de0 kernel/workqueue.c:3436
 kthread+0xd5a/0xf00 kernel/kthread.c:463
 ret_from_fork+0x207/0x6f0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Uninit was created at:
 slab_free_hook mm/slub.c:2466 [inline]
 slab_free mm/slub.c:6674 [inline]
 kfree+0x32b/0x1400 mm/slub.c:6882
 kobject_uevent_env+0x879/0x12a0 lib/kobject_uevent.c:639
 kobject_uevent+0x36/0x50 lib/kobject_uevent.c:656
 driver_register+0x60d/0x6a0 drivers/base/driver.c:257
 usb_register_driver+0x206/0x620 drivers/usb/core/driver.c:1078
 __usb_serial_register_drivers+0x319/0x16a0 drivers/usb/serial/usb-serial.c:1505
 usb_serial_module_init+0x33/0x40 drivers/usb/serial/aircable.c:156
 do_one_initcall+0x22b/0xad0 init/main.c:1378
 do_initcall_level+0x157/0x2e0 init/main.c:1440
 do_initcalls+0x176/0x310 init/main.c:1456
 do_basic_setup+0x1d/0x30 init/main.c:1475
 kernel_init_freeable+0x213/0x430 init/main.c:1688
 kernel_init+0x2f/0x5e0 init/main.c:1578
 ret_from_fork+0x207/0x6f0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

CPU: 1 UID: 0 PID: 3516 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Workqueue:  0x0 (events_unbound)
=====================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/26 21:02 upstream 63804fed149a a4c52dd6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in pick_task_fair
* Struck through repros no longer work on HEAD.