Re: [syzbot] [jfs?] [bfs?] kernel BUG in folio_set_bh (3)

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    174914ea5513 Merge tag 'v7.1-rc6-smb3-client-fixes' of git..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14ce352e580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b4166e8ea5fbf7e3
dashboard link: https://syzkaller.appspot.com/bug?extid=32ec8b5bd050c78741c2
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=170e96ec580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-174914ea.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/343eb2c4ac93/vmlinux-174914ea.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9e6c020ebad/bzImage-174914ea.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/b7e65fc0b31f/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+32ec8b5bd050c78741c2@xxxxxxxxxxxxxxxxxxxxxxxxx

qnx4: block size(32768) > page size(4096) not supported by filesystem
------------[ cut here ]------------
kernel BUG at fs/buffer.c:1479!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5529 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:folio_set_bh+0x1dc/0x1e0 fs/buffer.c:1479
Code: 4c 89 e2 e8 76 56 98 02 e9 42 ff ff ff e8 cc 76 6d ff 48 89 df 48 c7 c6 40 26 df 8b e8 7d be cf fe 90 0f 0b e8 b5 76 6d ff 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f
RSP: 0018:ffffc9000592f9e0 EFLAGS: 00010293
RAX: ffffffff82584f5b RBX: ffffea00010d3600 RCX: ffff88801faea540
RDX: 0000000000000000 RSI: 0000000000008000 RDI: 0000000000008000
RBP: dffffc0000000000 R08: ffffea00010d3607 R09: 1ffffd400021a6c0
R10: dffffc0000000000 R11: fffff9400021a6c1 R12: 0000000000000003
R13: 0000000000008000 R14: ffff88801ccb4740 R15: 0000000000008000
FS:  00007fd10f47c6c0(0000) GS:ffff88808c891000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9ccf517eb8 CR3: 0000000012fdd000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 folio_alloc_buffers+0x228/0x640 fs/buffer.c:849
 grow_dev_folio fs/buffer.c:979 [inline]
 grow_buffers fs/buffer.c:1020 [inline]
 __getblk_slow fs/buffer.c:1038 [inline]
 bdev_getblk+0x2cb/0x6e0 fs/buffer.c:1358
 __bread_gfp+0x89/0x3b0 fs/buffer.c:1412
 sb_bread include/linux/buffer_head.h:346 [inline]
 qnx4_fill_super+0x1c6/0x770 fs/qnx4/inode.c:216
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3834
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4360
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd10e59ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd10f47c028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd10e815fa0 RCX: 00007fd10e59ce59
RDX: 0000200000000100 RSI: 0000200000000000 RDI: 0000200000000040
RBP: 00007fd10e632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000002008080 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd10e816038 R14: 00007fd10e815fa0 R15: 00007ffe36651068
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:folio_set_bh+0x1dc/0x1e0 fs/buffer.c:1479
Code: 4c 89 e2 e8 76 56 98 02 e9 42 ff ff ff e8 cc 76 6d ff 48 89 df 48 c7 c6 40 26 df 8b e8 7d be cf fe 90 0f 0b e8 b5 76 6d ff 90 <0f> 0b 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f
RSP: 0018:ffffc9000592f9e0 EFLAGS: 00010293
RAX: ffffffff82584f5b RBX: ffffea00010d3600 RCX: ffff88801faea540
RDX: 0000000000000000 RSI: 0000000000008000 RDI: 0000000000008000
RBP: dffffc0000000000 R08: ffffea00010d3607 R09: 1ffffd400021a6c0
R10: dffffc0000000000 R11: fffff9400021a6c1 R12: 0000000000000003
R13: 0000000000008000 R14: ffff88801ccb4740 R15: 0000000000008000
FS:  00007fd10f47c6c0(0000) GS:ffff88808c891000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559ed6660138 CR3: 0000000012fdd000 CR4: 0000000000352ef0


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