[syzbot] [netfs?] kernel BUG in iov_iter_revert (2)

[syzbot <syzbot+404b4b745080b6210c6c@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    850925a8133c Merge tag '9p-for-6.12-rc5' of https://github..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17192940580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=309bb816d40abc28
dashboard link: https://syzkaller.appspot.com/bug?extid=404b4b745080b6210c6c
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10992940580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1503cca7980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-850925a8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c831c931f29c/vmlinux-850925a8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/85f584e52a7f/bzImage-850925a8.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+404b4b745080b6210c6c@syzkaller.appspotmail.com

R10: 0000000000000002 R11: 0000000000000246 R12: 00007f40bfa2741c
R13: 00007ffe565206f0 R14: 00007f40bfa2a5a1 R15: 0000000000000001
 </TASK>
------------[ cut here ]------------
kernel BUG at lib/iov_iter.c:624!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5311 Comm: syz-executor145 Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #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:iov_iter_revert+0x420/0x590 lib/iov_iter.c:624
Code: 42 80 3c 20 00 48 8b 1c 24 74 08 48 89 df e8 17 07 43 fd 4c 89 2b e9 04 01 00 00 45 85 ed 48 8b 3c 24 75 16 e8 41 48 d9 fc 90 <0f> 0b 41 83 fd 05 48 8b 3c 24 0f 84 58 01 00 00 48 89 f8 48 c1 e8
RSP: 0018:ffffc9000d09f740 EFLAGS: 00010293
RAX: ffffffff84bba22f RBX: 000000000001e098 RCX: ffff88801f03a440
RDX: 0000000000000000 RSI: ffffffff8f098180 RDI: ffff888048077cf0
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffffff84bb9f14
R10: 0000000000000004 R11: ffff88801f03a440 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff888048077ce0 R15: fffffffffffe1f68
FS:  000055556a75b380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555bd33aafa0 CR3: 0000000041784000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 netfs_reset_iter+0xce/0x130 fs/netfs/misc.c:133
 netfs_clear_unread fs/netfs/read_collect.c:22 [inline]
 netfs_read_subreq_terminated+0x1fe/0xad0 fs/netfs/read_collect.c:491
 netfs_read_to_pagecache+0x628/0x900 fs/netfs/buffered_read.c:306
 netfs_readahead+0x7e9/0x9d0 fs/netfs/buffered_read.c:421
 read_pages+0x17e/0x840 mm/readahead.c:160
 page_cache_ra_unbounded+0x774/0x8a0 mm/readahead.c:290
 do_page_cache_ra mm/readahead.c:320 [inline]
 force_page_cache_ra+0x280/0x2f0 mm/readahead.c:349
 force_page_cache_readahead mm/internal.h:357 [inline]
 generic_fadvise+0x522/0x830 mm/fadvise.c:106
 ksys_readahead mm/readahead.c:695 [inline]
 __do_sys_readahead mm/readahead.c:703 [inline]
 __se_sys_readahead mm/readahead.c:701 [inline]
 __x64_sys_readahead+0x1ac/0x230 mm/readahead.c:701
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f40bf9e5689
Code: 48 83 c4 28 c3 e8 17 1a 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe565206c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000bb
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f40bf9e5689
RDX: 000800000000000d RSI: 0000000000000005 RDI: 0000000000000006
RBP: 00007f40bfa273ee R08: 00007ffe56520466 R09: 0000550032313335
R10: 0000000000000002 R11: 0000000000000246 R12: 00007f40bfa2741c
R13: 00007ffe565206f0 R14: 00007f40bfa2a5a1 R15: 0000000000000001
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:iov_iter_revert+0x420/0x590 lib/iov_iter.c:624
Code: 42 80 3c 20 00 48 8b 1c 24 74 08 48 89 df e8 17 07 43 fd 4c 89 2b e9 04 01 00 00 45 85 ed 48 8b 3c 24 75 16 e8 41 48 d9 fc 90 <0f> 0b 41 83 fd 05 48 8b 3c 24 0f 84 58 01 00 00 48 89 f8 48 c1 e8
RSP: 0018:ffffc9000d09f740 EFLAGS: 00010293
RAX: ffffffff84bba22f RBX: 000000000001e098 RCX: ffff88801f03a440
RDX: 0000000000000000 RSI: ffffffff8f098180 RDI: ffff888048077cf0
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffffff84bb9f14
R10: 0000000000000004 R11: ffff88801f03a440 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff888048077ce0 R15: fffffffffffe1f68
FS:  000055556a75b380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555bd33aafa0 CR3: 0000000041784000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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