gfs2: fsid=syz:syz.s: gfs2_check_dirent: gfs2_dirent too small (not first in block)
gfs2: fsid=syz:syz.s: fatal: filesystem consistency error - inode = 12 2341, function = gfs2_dirent_scan, file = fs/gfs2/dir.c, line = 590
gfs2: fsid=syz:syz.s: G:  s:SH n:2/925 f:aqo t:SH d:EX/0 a:0 v:0 r:3 m:20 p:1
gfs2: fsid=syz:syz.s:  H: s:SH f:H e:0 p:5347 [syz.0.0] __gfs2_lookup+0xac/0x2a0 fs/gfs2/inode.c:989
gfs2: fsid=syz:syz.s:  H: s:UN f: e:0 p:0 [(ended)] 0x0
Oops: general protection fault, probably for non-canonical address 0xdffffc000000001e: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000000f0-0x00000000000000f7]
CPU: 0 UID: 0 PID: 5348 Comm: syz.0.0 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:pid_nr include/linux/pid.h:183 [inline]
RIP: 0010:dump_holder fs/gfs2/glock.c:2237 [inline]
RIP: 0010:gfs2_dump_glock+0xee3/0x1a60 fs/gfs2/glock.c:2351
Code: e8 c2 b8 11 fe 4c 8b 2b 4d 85 ed 74 33 e8 e5 f2 a4 fd 49 8d 9d f0 00 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 5a 07 00 00 48 63 03 48 89 44 24 10 eb 0e
RSP: 0018:ffffc9000e56eaa0 EFLAGS: 00010207
RAX: 000000000000001e RBX: 00000000000000f4 RCX: dffffc0000000000
RDX: ffffc90020001000 RSI: 00000000000028df RDI: 00000000000028e0
RBP: ffffc9000e56ed90 R08: ffffc9000e56eb7f R09: 0000000000000000
R10: ffffc9000e56eb60 R11: fffff52001cadd70 R12: ffff88800e490000
R13: 0000000000000004 R14: 1ffff11001c92004 R15: ffff88800e490020
FS:  00007f7a11aad6c0(0000) GS:ffff88808c812000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7a11a8bfe8 CR3: 000000003373b000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 gfs2_consist_inode_i+0xf5/0x110 fs/gfs2/util.c:345
 gfs2_dirent_scan+0x545/0x690 fs/gfs2/dir.c:-1
 gfs2_dirent_search+0x358/0x920 fs/gfs2/dir.c:854
 gfs2_dir_search+0x4c/0x220 fs/gfs2/dir.c:1651
 gfs2_lookupi+0x45b/0x640 fs/gfs2/inode.c:354
 __gfs2_lookup+0xac/0x2a0 fs/gfs2/inode.c:989
 __lookup_slow+0x2b7/0x410 fs/namei.c:1915
 lookup_slow+0x53/0x70 fs/namei.c:1932
 walk_component fs/namei.c:2278 [inline]
 lookup_last fs/namei.c:2785 [inline]
 path_lookupat+0x3f5/0x8c0 fs/namei.c:2809
 filename_lookup+0x256/0x5d0 fs/namei.c:2838
 kern_path+0x3d/0x150 fs/namei.c:3044
 unix_find_bsd net/unix/af_unix.c:1215 [inline]
 unix_find_other+0x19d/0xb40 net/unix/af_unix.c:1281
 unix_dgram_sendmsg+0x754/0x18b0 net/unix/af_unix.c:2152
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
 __sys_sendmmsg+0x27c/0x4e0 net/socket.c:2841
 __do_sys_sendmmsg net/socket.c:2868 [inline]
 __se_sys_sendmmsg net/socket.c:2865 [inline]
 __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2865
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7a10b9c819
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:00007f7a11aacfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f7a10e16090 RCX: 00007f7a10b9c819
RDX: 0000000000000002 RSI: 0000200000005a40 RDI: 0000000000000006
RBP: 00007f7a10c32c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7a10e16128 R14: 00007f7a10e16090 R15: 00007ffe344c27c8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:pid_nr include/linux/pid.h:183 [inline]
RIP: 0010:dump_holder fs/gfs2/glock.c:2237 [inline]
RIP: 0010:gfs2_dump_glock+0xee3/0x1a60 fs/gfs2/glock.c:2351
Code: e8 c2 b8 11 fe 4c 8b 2b 4d 85 ed 74 33 e8 e5 f2 a4 fd 49 8d 9d f0 00 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 5a 07 00 00 48 63 03 48 89 44 24 10 eb 0e
RSP: 0018:ffffc9000e56eaa0 EFLAGS: 00010207
RAX: 000000000000001e RBX: 00000000000000f4 RCX: dffffc0000000000
RDX: ffffc90020001000 RSI: 00000000000028df RDI: 00000000000028e0
RBP: ffffc9000e56ed90 R08: ffffc9000e56eb7f R09: 0000000000000000
R10: ffffc9000e56eb60 R11: fffff52001cadd70 R12: ffff88800e490000
R13: 0000000000000004 R14: 1ffff11001c92004 R15: ffff88800e490020
FS:  00007f7a11aad6c0(0000) GS:ffff88808c812000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7a11a8bfe8 CR3: 000000003373b000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	e8 c2 b8 11 fe       	call   0xfe11b8c7
   5:	4c 8b 2b             	mov    (%rbx),%r13
   8:	4d 85 ed             	test   %r13,%r13
   b:	74 33                	je     0x40
   d:	e8 e5 f2 a4 fd       	call   0xfda4f2f7
  12:	49 8d 9d f0 00 00 00 	lea    0xf0(%r13),%rbx
  19:	48 89 d8             	mov    %rbx,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	0f b6 04 08          	movzbl (%rax,%rcx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 5a 07 00 00    	jne    0x790
  36:	48 63 03             	movslq (%rbx),%rax
  39:	48 89 44 24 10       	mov    %rax,0x10(%rsp)
  3e:	eb 0e                	jmp    0x4e