syzbot

 get_signal+0x25fb/0x2770 kernel/signal.c:2917
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:1460!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 5366 Comm: syz-executor143 Not tainted 6.11.0-syzkaller-03917-ga940d9a43e62 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:folio_get include/linux/mm.h:1460 [inline]
RIP: 0010:get_page include/linux/mm.h:1466 [inline]
RIP: 0010:iter_folioq_get_pages lib/iov_iter.c:1030 [inline]
RIP: 0010:__iov_iter_get_pages_alloc+0x1d1e/0x2240 lib/iov_iter.c:1201
Code: b0 8b 48 89 df e8 c2 b0 48 fd 90 0f 0b 49 89 c5 e9 99 f6 ff ff e8 82 2f 04 fd 48 c7 c6 00 ba b0 8b 4c 89 e7 e8 a3 b0 48 fd 90 <0f> 0b e8 6b 2f 04 fd 4c 8b 64 24 48 49 83 ec 01 e9 94 fd ff ff 4c
RSP: 0018:ffffc90003c8ece8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: ffff888025930000 RSI: ffffffff848814ed RDI: ffff888025930444
RBP: ffffea0000ef1534 R08: 0000000000000001 R09: fffffbfff2d3a8fd
R10: ffffffff969d47ef R11: 00000000000001fc R12: ffffea0000ef1500
R13: ffff8880300a4800 R14: 0000000000001000 R15: 0000000000001000
FS:  0000000000000000(0000) GS:ffff88806a700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 0000000031d12000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 iov_iter_get_pages_alloc2+0x53/0xf0 lib/iov_iter.c:1225
 p9_get_mapped_pages.part.0.constprop.0+0x4ca/0x7d0 net/9p/trans_virtio.c:333
 p9_get_mapped_pages net/9p/trans_virtio.c:318 [inline]
 p9_virtio_zc_request+0x1be/0x1390 net/9p/trans_virtio.c:439
 p9_client_zc_rpc.constprop.0+0x29a/0x880 net/9p/client.c:808
 p9_client_write+0x447/0x680 net/9p/client.c:1631
 v9fs_issue_write+0xe2/0x180 fs/9p/vfs_addr.c:59
 netfs_do_issue_write+0x92/0x110 fs/netfs/write_issue.c:223
 netfs_issue_write fs/netfs/write_issue.c:250 [inline]
 netfs_advance_write fs/netfs/write_issue.c:291 [inline]
 netfs_advance_write+0x384/0xbd0 fs/netfs/write_issue.c:259
 netfs_write_folio+0xc44/0x18f0 fs/netfs/write_issue.c:469
 netfs_writepages+0x2ba/0xb90 fs/netfs/write_issue.c:541
 do_writepages+0x1a3/0x7f0 mm/page-writeback.c:2683
 filemap_fdatawrite_wbc mm/filemap.c:397 [inline]
 filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:387
 __filemap_fdatawrite_range+0xba/0x100 mm/filemap.c:430
 v9fs_dir_release+0x429/0x590 fs/9p/vfs_dir.c:219
 __fput+0x3f6/0xb60 fs/file_table.c:431
 task_work_run+0x14e/0x250 kernel/task_work.c:228
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xaa3/0x2bb0 kernel/exit.c:882
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031
 get_signal+0x25fb/0x2770 kernel/signal.c:2917
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f53cae71436
Code: Unable to access opcode bytes at 0x7f53cae7140c.
RSP: 002b:00007f53cae03200 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007f53caef4318 RCX: 00007f53cae714a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000000249f0
RBP: 00007f53caef4310 R08: 0000000000000000 R09: 00007f53cae036c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f53caec12fc
R13: 00007f53caef431c R14: 0030656c69662f2e R15: 00007ffdb9c6eba8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:folio_get include/linux/mm.h:1460 [inline]
RIP: 0010:get_page include/linux/mm.h:1466 [inline]
RIP: 0010:iter_folioq_get_pages lib/iov_iter.c:1030 [inline]
RIP: 0010:__iov_iter_get_pages_alloc+0x1d1e/0x2240 lib/iov_iter.c:1201
Code: b0 8b 48 89 df e8 c2 b0 48 fd 90 0f 0b 49 89 c5 e9 99 f6 ff ff e8 82 2f 04 fd 48 c7 c6 00 ba b0 8b 4c 89 e7 e8 a3 b0 48 fd 90 <0f> 0b e8 6b 2f 04 fd 4c 8b 64 24 48 49 83 ec 01 e9 94 fd ff ff 4c
RSP: 0018:ffffc90003c8ece8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: ffff888025930000 RSI: ffffffff848814ed RDI: ffff888025930444
RBP: ffffea0000ef1534 R08: 0000000000000001 R09: fffffbfff2d3a8fd
R10: ffffffff969d47ef R11: 00000000000001fc R12: ffffea0000ef1500
R13: ffff8880300a4800 R14: 0000000000001000 R15: 0000000000001000
FS:  0000000000000000(0000) GS:ffff88806a700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 0000000035464000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400