BUG: soft lockup in kcov

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-6.1	INFO: rcu detected stall in kcov_close				4	18d	24d	0/3	upstream: reported on 2024/05/26 09:21
watchdog: BUG: soft lockup - CPU#1 stuck for 21s! [syz-executor.0:5128]
Modules linked in:
irq event stamp: 50032
hardirqs last  enabled at (50031): [<ffff800008828530>] free_unref_page+0x150/0x204 mm/page_alloc.c:3417
hardirqs last disabled at (50032): [<ffff80001199ab70>] enter_el1_irq_or_nmi+0x10/0x1c arch/arm64/kernel/entry-common.c:227
softirqs last  enabled at (27352): [<ffff800010928478>] spin_unlock_bh include/linux/spinlock.h:408 [inline]
softirqs last  enabled at (27352): [<ffff800010928478>] fib6_run_gc+0x1dc/0x2f8 net/ipv6/ip6_fib.c:2339
softirqs last disabled at (27336): [<ffff80001092833c>] spin_trylock_bh include/linux/spinlock.h:423 [inline]
softirqs last disabled at (27336): [<ffff80001092833c>] fib6_run_gc+0xa0/0x2f8 net/ipv6/ip6_fib.c:2321
CPU: 1 PID: 5128 Comm: syz-executor.0 Not tainted 5.15.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : free_unref_page+0x160/0x204 mm/page_alloc.c:3418
lr : free_unref_page+0x150/0x204 mm/page_alloc.c:3417
sp : ffff80001e3275f0
x29: ffff80001e3275f0 x28: dfff800000000000 x27: ffff0000e5d77800
x26: 1fffe0001cbaef02 x25: ffff800014950ff8 x24: dfff800000000000
x23: 0000000000000000 x22: ffff8000148b0858 x21: 0000000000000000
x20: fffffc00039a0600 x19: ffff800014951000 x18: 1fffe0003690158e
x17: 1fffe0003690158e x16: ffff8000082eb9fc x15: ffff8000081ab890
x14: 1ffff0000292a06a x13: dfff800000000000 x12: 0000000000000003
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000080
x8 : 00000000000000c0 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000000 x3 : ffff80000804685c
x2 : 0000000000000001 x1 : ffff800011aead00 x0 : ffff80019ff68000
Call trace:
 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
 free_unref_page+0x160/0x204 mm/page_alloc.c:3417
 free_the_page mm/page_alloc.c:705 [inline]
 __free_pages+0x180/0x1d4 mm/page_alloc.c:5499
 __vunmap+0x804/0x988 mm/vmalloc.c:2621
 __vfree mm/vmalloc.c:2669 [inline]
 vfree+0xbc/0x154 mm/vmalloc.c:2700
 kcov_put kernel/kcov.c:408 [inline]
 kcov_close+0x44/0xa0 kernel/kcov.c:510
 __fput+0x30c/0x7f0 fs/file_table.c:280
 ____fput+0x20/0x30 fs/file_table.c:308
 task_work_run+0x130/0x1e4 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0x670/0x20bc kernel/exit.c:872
 do_group_exit+0x110/0x268 kernel/exit.c:994
 get_signal+0x634/0x1550 kernel/signal.c:2889
 do_signal arch/arm64/kernel/signal.c:890 [inline]
 do_notify_resume+0x3d0/0x32b8 arch/arm64/kernel/signal.c:943
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
 el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609
 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584