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BUG: KMSAN: uninit-value in run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1698
CPU: 1 PID: 11514 Comm: syz-fuzzer Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x191/0x1f0 lib/dump_stack.c:113
 kmsan_report+0x13a/0x2b0 mm/kmsan/kmsan_report.c:108
 __msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:250
 __hlist_del include/linux/list.h:763 [inline]
 detach_timer kernel/time/timer.c:811 [inline]
 expire_timers kernel/time/timer.c:1356 [inline]
 __run_timers+0xb99/0x11a0 kernel/time/timer.c:1685
 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1698
 __do_softirq+0x4a1/0x83a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:375 [inline]
 irq_exit+0x230/0x280 kernel/softirq.c:416
 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:537
 smp_apic_timer_interrupt+0x48/0x70 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0x2e/0x40 arch/x86/entry/entry_64.S:837
 </IRQ>
RIP: 0033:0x4117ed
Code: 48 83 ec 10 48 89 6c 24 08 48 8d 6c 24 08 0f b6 05 2c 77 42 01 84 c0 74 2f 48 8b 44 24 18 48 89 c1 48 81 f9 00 10 00 00 72 08 <48> 8b 00 48 85 c0 75 7a 48 8b 44 24 20 48 85 c0 74 0c 48 8b 0d 62
RSP: 002b:00007ffcd0ec2570 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 000000c4202a1b80 RBX: 000000c42001b300 RCX: 000000c4202a1b80
RDX: 000000c4202a1b80 RSI: 0000000000459df0 RDI: 0000000000456cd0
RBP: 00007ffcd0ec2578 R08: 000000c42eacc780 R09: 0000000000000000
R10: 0000000000000001 R11: 000000c43e90e85b R12: 0000000000000003
R13: 000000c43e90e844 R14: 00000000000000cc R15: 000000c43e90e830

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:150 [inline]
 kmsan_internal_poison_shadow+0x53/0x100 mm/kmsan/kmsan.c:134
 kmsan_slab_free+0x8d/0x100 mm/kmsan/kmsan_hooks.c:123
 slab_free_freelist_hook mm/slub.c:1472 [inline]
 slab_free mm/slub.c:3038 [inline]
 kfree+0x4c1/0x2db0 mm/slub.c:3980
 do_syslog+0x312d/0x3160 kernel/printk/printk.c:1417
 kmsg_read+0x142/0x1a0 fs/proc/kmsg.c:40
 proc_reg_read+0x25f/0x360 fs/proc/inode.c:223
 __vfs_read+0x1a9/0xc90 fs/read_write.c:425
 vfs_read+0x359/0x6f0 fs/read_write.c:461
 ksys_read+0x265/0x430 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read+0x92/0xb0 fs/read_write.c:595
 __x64_sys_read+0x4a/0x70 fs/read_write.c:595
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
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