RAX: ffffffffffffffda RBX: 00007f0ebc7326d4 RCX: 0000000000455a99
RDX: 0000000020000180 RSI: 00000000c0c0583b RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000004be46c R14: 00000000004cc990 R15: 0000000000000045
BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
PGD 8000000089cca067 P4D 8000000089cca067 PUD 89dc7067 PMD 0 
Oops: 0000 [#1] SMP PTI
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 6588 Comm: syz-executor7 Not tainted 4.17.0+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:197 [inline]
RIP: 0010:compound_head include/linux/page-flags.h:142 [inline]
RIP: 0010:PageLocked include/linux/page-flags.h:272 [inline]
RIP: 0010:grow_dev_page fs/buffer.c:942 [inline]
RIP: 0010:grow_buffers fs/buffer.c:1009 [inline]
RIP: 0010:__getblk_slow fs/buffer.c:1036 [inline]
RIP: 0010:__getblk_gfp+0x5bf/0x1630 fs/buffer.c:1316
RSP: 0018:ffff8800ae1af0c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000020 RCX: 0000000000000000
RDX: ffff8801ba852618 RSI: 0000000000000000 RDI: 0000000000022f16
RBP: ffff8800ae1af208 R08: 0000000001080000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff86575950 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8801d62a48d0
FS:  00007f0ebc732700(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000020 CR3: 00000000ae050000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 sb_getblk include/linux/buffer_head.h:327 [inline]
 ext4_read_block_bitmap_nowait+0x506/0x3d60 fs/ext4/balloc.c:441
 ext4_mb_init_cache+0x702/0x2930 fs/ext4/mballoc.c:863
 ext4_mb_load_buddy_gfp+0xbac/0x1cf0 fs/ext4/mballoc.c:1161
 ext4_mb_load_buddy fs/ext4/mballoc.c:1240 [inline]
 ext4_mballoc_query_range+0x1b0/0x12d0 fs/ext4/mballoc.c:5342
 ext4_getfsmap_datadev+0x11c9/0x1910 fs/ext4/fsmap.c:534
 ext4_getfsmap+0x12e1/0x13c0 fs/ext4/fsmap.c:705
 ext4_ioc_getfsmap fs/ext4/ioctl.c:566 [inline]
 ext4_ioctl+0x570b/0x7060 fs/ext4/ioctl.c:640
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0xcbd/0x24b0 fs/ioctl.c:686
 ksys_ioctl fs/ioctl.c:701 [inline]
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x280/0x320 fs/ioctl.c:706
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455a99
RSP: 002b:00007f0ebc731c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0ebc7326d4 RCX: 0000000000455a99
RDX: 0000000020000180 RSI: 00000000c0c0583b RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014
R13: 00000000004be46c R14: 00000000004cc990 R15: 0000000000000045
Code: ff ff ff 44 89 e9 e8 91 80 ad ff 49 89 c6 4c 8b ab 20 03 00 00 8b 83 a8 0f 00 00 89 45 d0 49 8d 5e 20 4d 85 ed 0f 85 35 01 00 00 <4d> 8b 7e 20 48 89 9d e0 fe ff ff 48 89 df e8 0e 3c dc ff 48 8b 
RIP: __read_once_size include/linux/compiler.h:197 [inline] RSP: ffff8800ae1af0c0
RIP: compound_head include/linux/page-flags.h:142 [inline] RSP: ffff8800ae1af0c0
RIP: PageLocked include/linux/page-flags.h:272 [inline] RSP: ffff8800ae1af0c0
RIP: grow_dev_page fs/buffer.c:942 [inline] RSP: ffff8800ae1af0c0
RIP: grow_buffers fs/buffer.c:1009 [inline] RSP: ffff8800ae1af0c0
RIP: __getblk_slow fs/buffer.c:1036 [inline] RSP: ffff8800ae1af0c0
RIP: __getblk_gfp+0x5bf/0x1630 fs/buffer.c:1316 RSP: ffff8800ae1af0c0
CR2: 0000000000000020
---[ end trace 7428cb08474188a3 ]---