IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
PGD 800000022b66d067 P4D 800000022b66d067 PUD 22f631067 PMD 0 
Oops: 0000 [#1] SMP PTI
CPU: 1 PID: 3830 Comm: syz.0.15 Not tainted 4.19.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:nilfs_btree_prepare_insert fs/nilfs2/btree.c:1077 [inline]
RIP: 0010:nilfs_btree_insert+0xf8/0x7a0 fs/nilfs2/btree.c:1237
Code: 38 0f b6 43 01 0f b7 8b e0 00 00 00 48 8b 7d b8 83 f8 01 89 4d a4 4c 8d af 80 00 00 00 0f 8e 77 06 00 00 48 8b 97 80 00 00 00 <48> 8b 52 28 0f b7 52 02 39 d1 0f 8f 71 06 00 00 c7 45 a8 00 00 00
RSP: 0018:ffffc9000272fa70 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff88022e3e0018 RCX: 000000000000003f
RDX: 0000000000000000 RSI: 0000000000000007 RDI: ffff88022bf28000
RBP: ffffc9000272faf0 R08: 0000000000000000 R09: 00000000f47789eb
R10: 0000000000000000 R11: ffff88022db0b680 R12: ffff88022e3541a0
R13: ffff88022bf28080 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fed4fd976c0(0000) GS:ffff880237b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 0000000223d64000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 nilfs_bmap_do_insert fs/nilfs2/bmap.c:121 [inline]
 nilfs_bmap_insert+0xcc/0x130 fs/nilfs2/bmap.c:147
 nilfs_get_block+0x143/0x200 fs/nilfs2/inode.c:96
 __block_write_begin_int+0x16b/0x5a0 fs/buffer.c:1966
 __block_write_begin fs/buffer.c:2016 [inline]
 block_write_begin+0x44/0xc0 fs/buffer.c:2075
 nilfs_write_begin+0x54/0x90 fs/nilfs2/inode.c:267
 generic_perform_write+0xbe/0x1b0 mm/filemap.c:3139
 __generic_file_write_iter+0x147/0x1c0 mm/filemap.c:3264
 generic_file_write_iter+0x10e/0x210 mm/filemap.c:3292
 call_write_iter include/linux/fs.h:1808 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x11a/0x170 fs/read_write.c:487
 vfs_write fs/read_write.c:549 [inline]
 vfs_write+0xaa/0x1a0 fs/read_write.c:533
 ksys_write+0x53/0xc0 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x15/0x20 fs/read_write.c:607
 do_syscall_64+0x69/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fed50311ef9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fed4fd97038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fed504adf80 RCX: 00007fed50311ef9
RDX: 0000000000004000 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007fed5037f93e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fed504adf80 R15: 00007fff60b7acc8
Modules linked in:
CR2: 0000000000000028
---[ end trace 09cd883f370f8685 ]---
RIP: 0010:nilfs_btree_prepare_insert fs/nilfs2/btree.c:1077 [inline]
RIP: 0010:nilfs_btree_insert+0xf8/0x7a0 fs/nilfs2/btree.c:1237
Code: 38 0f b6 43 01 0f b7 8b e0 00 00 00 48 8b 7d b8 83 f8 01 89 4d a4 4c 8d af 80 00 00 00 0f 8e 77 06 00 00 48 8b 97 80 00 00 00 <48> 8b 52 28 0f b7 52 02 39 d1 0f 8f 71 06 00 00 c7 45 a8 00 00 00
RSP: 0018:ffffc9000272fa70 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff88022e3e0018 RCX: 000000000000003f
RDX: 0000000000000000 RSI: 0000000000000007 RDI: ffff88022bf28000
RBP: ffffc9000272faf0 R08: 0000000000000000 R09: 00000000f47789eb
R10: 0000000000000000 R11: ffff88022db0b680 R12: ffff88022e3541a0
R13: ffff88022bf28080 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fed4fd976c0(0000) GS:ffff880237b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000028 CR3: 0000000223d64000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	38 0f                	cmp    %cl,(%rdi)
   2:	b6 43                	mov    $0x43,%dh
   4:	01 0f                	add    %ecx,(%rdi)
   6:	b7 8b                	mov    $0x8b,%bh
   8:	e0 00                	loopne 0xa
   a:	00 00                	add    %al,(%rax)
   c:	48 8b 7d b8          	mov    -0x48(%rbp),%rdi
  10:	83 f8 01             	cmp    $0x1,%eax
  13:	89 4d a4             	mov    %ecx,-0x5c(%rbp)
  16:	4c 8d af 80 00 00 00 	lea    0x80(%rdi),%r13
  1d:	0f 8e 77 06 00 00    	jle    0x69a
  23:	48 8b 97 80 00 00 00 	mov    0x80(%rdi),%rdx
* 2a:	48 8b 52 28          	mov    0x28(%rdx),%rdx <-- trapping instruction
  2e:	0f b7 52 02          	movzwl 0x2(%rdx),%edx
  32:	39 d1                	cmp    %edx,%ecx
  34:	0f 8f 71 06 00 00    	jg     0x6ab
  3a:	c7                   	.byte 0xc7
  3b:	45 a8 00             	rex.RB test $0x0,%al