syzbot

 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:1135!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 PID: 12 Comm: kworker/u8:1 Not tainted 6.9.0-rc2-next-20240402-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound io_ring_exit_work
RIP: 0010:put_page_testzero include/linux/mm.h:1135 [inline]
RIP: 0010:folio_put_testzero include/linux/mm.h:1141 [inline]
RIP: 0010:folio_put include/linux/mm.h:1508 [inline]
RIP: 0010:put_page include/linux/mm.h:1581 [inline]
RIP: 0010:__io_remove_buffers+0x8ee/0x8f0 io_uring/kbuf.c:196
Code: ff fb ff ff 48 c7 c7 3c 68 a9 8f e8 fc b6 56 fd e9 ee fb ff ff e8 12 dc f1 fc 48 89 ef 48 c7 c6 60 ff 1e 8c e8 13 20 3b fd 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa
RSP: 0018:ffffc90000117830 EFLAGS: 00010246
RAX: 12798bbc5474ca00 RBX: 0000000000000000 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8bcad5c0 RDI: 0000000000000001
RBP: ffffea0000880c40 R08: ffffffff92f3a5ef R09: 1ffffffff25e74bd
R10: dffffc0000000000 R11: fffffbfff25e74be R12: 0000000000000008
R13: 0000000000000002 R14: ffff88802d20d280 R15: ffffea0000880c74
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200020c4 CR3: 000000007d97a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 io_put_bl io_uring/kbuf.c:229 [inline]
 io_destroy_buffers+0x14e/0x490 io_uring/kbuf.c:243
 io_ring_ctx_free+0x818/0xe70 io_uring/io_uring.c:2710
 io_ring_exit_work+0x7c7/0x850 io_uring/io_uring.c:2941
 process_one_work kernel/workqueue.c:3218 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:put_page_testzero include/linux/mm.h:1135 [inline]
RIP: 0010:folio_put_testzero include/linux/mm.h:1141 [inline]
RIP: 0010:folio_put include/linux/mm.h:1508 [inline]
RIP: 0010:put_page include/linux/mm.h:1581 [inline]
RIP: 0010:__io_remove_buffers+0x8ee/0x8f0 io_uring/kbuf.c:196
Code: ff fb ff ff 48 c7 c7 3c 68 a9 8f e8 fc b6 56 fd e9 ee fb ff ff e8 12 dc f1 fc 48 89 ef 48 c7 c6 60 ff 1e 8c e8 13 20 3b fd 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa
RSP: 0018:ffffc90000117830 EFLAGS: 00010246
RAX: 12798bbc5474ca00 RBX: 0000000000000000 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8bcad5c0 RDI: 0000000000000001
RBP: ffffea0000880c40 R08: ffffffff92f3a5ef R09: 1ffffffff25e74bd
R10: dffffc0000000000 R11: fffffbfff25e74be R12: 0000000000000008
R13: 0000000000000002 R14: ffff88802d20d280 R15: ffffea0000880c74
FS:  0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f31a71870f0 CR3: 000000007930c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400