------------[ cut here ]------------
mm == current->mm
WARNING: kernel/fork.c:721 at __mmdrop+0x5de/0x750 kernel/fork.c:721, CPU#0: syz.1.9527/27039
Modules linked in:
CPU: 0 UID: 0 PID: 27039 Comm: syz.1.9527 Tainted: G     U    I  L      syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:__mmdrop+0x5de/0x750 kernel/fork.c:721
Code: 00 90 0f 0b e8 f3 c9 41 00 90 0f 0b 90 e9 e9 fa ff ff e8 e5 c9 41 00 48 89 df e8 fd 2f aa 00 e9 c0 fb ff ff e8 d3 c9 41 00 90 <0f> 0b 90 e9 85 fa ff ff e8 c5 c9 41 00 90 0f 0b 90 e9 5f fb ff ff
RSP: 0018:ffffc900045df8a0 EFLAGS: 00010283
RAX: 00000000000025da RBX: ffff888074dbbd40 RCX: ffffc9000d9c1000
RDX: 0000000000080000 RSI: ffffffff81c4c5ed RDI: ffff8880277ce030
RBP: ffffc900045df938 R08: 0000000000000001 R09: ffffed100e9b77a8
R10: ffff888074dbbd43 R11: 0000000000000000 R12: ffff8880277cdac0
R13: ffff888025dc3c80 R14: ffff888025dc3c80 R15: ffff8880b843bcb0
FS:  00007ff8efa6e6c0(0000) GS:ffff8881245bf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ed0fff8 CR3: 000000003a98c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 mmdrop include/linux/sched/mm.h:55 [inline]
 mmdrop_sched include/linux/sched/mm.h:83 [inline]
 mmdrop_lazy_tlb_sched include/linux/sched/mm.h:110 [inline]
 finish_task_switch.isra.0+0x779/0xb80 kernel/sched/core.c:5172
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0x102b/0x6000 kernel/sched/core.c:6902
 __schedule_loop kernel/sched/core.c:6984 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:6999
 futex_do_wait+0x88/0x180 kernel/futex/waitwake.c:358
 __futex_wait+0x1c4/0x300 kernel/futex/waitwake.c:687
 futex_wait+0xed/0x380 kernel/futex/waitwake.c:715
 do_futex+0x1ef/0x350 kernel/futex/syscalls.c:130
 __do_sys_futex kernel/futex/syscalls.c:207 [inline]
 __se_sys_futex kernel/futex/syscalls.c:188 [inline]
 __x64_sys_futex+0x34f/0x4d0 kernel/futex/syscalls.c:188
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff8eeb9bf79
Code: Unable to access opcode bytes at 0x7ff8eeb9bf4f.
RSP: 002b:00007ff8efa6e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007ff8eee15fa8 RCX: 00007ff8eeb9bf79
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff8eee15fa8
RBP: 00007ff8eee15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff8eee16038 R14: 00007ffe3d651310 R15: 00007ffe3d6513f8
 </TASK>