Re: [syzbot] [gfs2?] general protection fault in gfs2_evict_inode (2)

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    a5541c0811a0 Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=15551327880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cbd4e584773e9397
dashboard link: https://syzkaller.appspot.com/bug?extid=8a5fc6416c175cecea34
compiler:       Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1718796f880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1735df8f880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4b7702208fb9/disk-a5541c08.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9ec0153ec051/vmlinux-a5541c08.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6f8725ad290a/Image-a5541c08.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/b4c763067524/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8a5fc6416c175cecea34@xxxxxxxxxxxxxxxxxxxxxxxxx

gfs2: fsid=syz:syz.0: error recovering journal 0: -5
Unable to handle kernel NULL pointer dereference at virtual address 000000000000008c
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006
  CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=000000010dd7c000
[000000000000008c] pgd=080000010bf77003, p4d=080000010bf77003, pud=080000010a9f1003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 3071 Comm: syz-executor179 Not tainted 6.1.0-rc8-syzkaller-33330-ga5541c0811a0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : evict_linked_inode fs/gfs2/super.c:1330 [inline]
pc : gfs2_evict_inode+0x6f8/0x918 fs/gfs2/super.c:1385
lr : evict_linked_inode fs/gfs2/super.c:1328 [inline]
lr : gfs2_evict_inode+0x6ec/0x918 fs/gfs2/super.c:1385
sp : ffff80000ff73830
x29: ffff80000ff738a0 x28: 0000000000000000 x27: 0000000000000000
x26: ffff0000cb74c728 x25: 0000000000008004 x24: ffff0000c9b25110
x23: ffff0000cb74c000 x22: ffff0000c9b24e70 x21: ffff0000cb74c000
x20: ffff0000ca579770 x19: ffff0000ca5792c0 x18: 00000000000000c0
x17: ffff80000dda8198 x16: ffff80000dbe6158 x15: ffff0000c407cec0
x14: 00000000000000b8 x13: 00000000ffffffff x12: ffff0000c407cec0
x11: ff80800009278314 x10: 0000000000000000 x9 : ffff800009278314
x8 : 0000000000000000 x7 : ffff80000862aa80 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000001 x1 : 0000000000000000 x0 : ffff0000cb74c000
Call trace:
 evict_linked_inode fs/gfs2/super.c:1330 [inline]
 gfs2_evict_inode+0x6f8/0x918 fs/gfs2/super.c:1385
 evict+0xec/0x334 fs/inode.c:664
 iput_final fs/inode.c:1747 [inline]
 iput+0x2c4/0x324 fs/inode.c:1773
 gfs2_jindex_free+0x10c/0x16c fs/gfs2/super.c:75
 init_journal+0x518/0xcbc fs/gfs2/ops_fstype.c:871
 init_inodes+0x74/0x184 fs/gfs2/ops_fstype.c:889
 gfs2_fill_super+0x630/0x874 fs/gfs2/ops_fstype.c:1247
 get_tree_bdev+0x1e8/0x2a0 fs/super.c:1324
 gfs2_get_tree+0x30/0xc0 fs/gfs2/ops_fstype.c:1330
 vfs_get_tree+0x40/0x140 fs/super.c:1531
 do_new_mount+0x1dc/0x4e4 fs/namespace.c:3040
 path_mount+0x358/0x890 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount fs/namespace.c:3568 [inline]
 __arm64_sys_mount+0x2c4/0x3c4 fs/namespace.c:3568
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
Code: 97ff3736 f94482e8 aa1703e0 2a1f03e1 (b9408d02) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	97ff3736 	bl	0xfffffffffffcdcd8
   4:	f94482e8 	ldr	x8, [x23, #2304]
   8:	aa1703e0 	mov	x0, x23
   c:	2a1f03e1 	mov	w1, wzr
* 10:	b9408d02 	ldr	w2, [x8, #140] <-- trapping instruction