general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 6281 Comm: syz.1.118 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
RIP: 0010:ext4_free_ext_path fs/ext4/extents.c:128 [inline]
RIP: 0010:ext4_ext_map_blocks+0x2cf3/0x6800 fs/ext4/extents.c:4494
Code: 8b 04 24 89 18 89 9c 24 38 01 00 00 4c 8b 7c 24 10 4d 85 ff 0f 84 bd 00 00 00 e8 78 dc 58 ff 49 8d 7f 08 48 89 f8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 3d 1e 00 00 41 0f b7 47 08 c1 e0 04 48
RSP: 0018:ffffc900040f6e00 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000cf0a000 RSI: 0000000000016d93 RDI: 0000000000000003
RBP: ffffc900040f70b0 R08: ffff8880588aa5d3 R09: 1ffff1100b1154ba
R10: dffffc0000000000 R11: ffffed100b1154bb R12: 0000000000000000
R13: 1ffff9200081edec R14: dffffc0000000000 R15: fffffffffffffffb
FS:  00007f65c05b86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f65bf7e9f00 CR3: 0000000021dad000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 ext4_map_blocks+0x9e2/0x1b80 fs/ext4/inode.c:652
 _ext4_get_block+0x1eb/0x480 fs/ext4/inode.c:794
 ext4_block_write_begin+0x55d/0x14f0 fs/ext4/inode.c:1091
 ext4_write_begin+0x5de/0x1070 fs/ext4/ext4_jbd2.h:-1
 ext4_da_write_begin+0x2df/0x9c0 fs/ext4/inode.c:2908
 generic_perform_write+0x2fe/0x5c0 mm/filemap.c:4031
 ext4_buffered_write_iter+0xcc/0x350 fs/ext4/file.c:299
 ext4_file_write_iter+0x1d9/0x1880 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2018 [inline]
 aio_write+0x564/0x7d0 fs/aio.c:1593
 __io_submit_one fs/aio.c:-1 [inline]
 io_submit_one+0x73f/0x12a0 fs/aio.c:2012
 __do_sys_io_submit fs/aio.c:2071 [inline]
 __se_sys_io_submit+0x1a1/0x310 fs/aio.c:2041
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f65bf79c819
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:00007f65c05b8028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 00007f65bfa15fa0 RCX: 00007f65bf79c819
RDX: 0000200000000540 RSI: 0000000000000008 RDI: 00007f65c0576000
RBP: 00007f65bf832c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f65bfa16038 R14: 00007f65bfa15fa0 R15: 00007ffcb3274998
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_ext_drop_refs fs/ext4/extents.c:119 [inline]
RIP: 0010:ext4_free_ext_path fs/ext4/extents.c:128 [inline]
RIP: 0010:ext4_ext_map_blocks+0x2cf3/0x6800 fs/ext4/extents.c:4494
Code: 8b 04 24 89 18 89 9c 24 38 01 00 00 4c 8b 7c 24 10 4d 85 ff 0f 84 bd 00 00 00 e8 78 dc 58 ff 49 8d 7f 08 48 89 f8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 3d 1e 00 00 41 0f b7 47 08 c1 e0 04 48
RSP: 0018:ffffc900040f6e00 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000cf0a000 RSI: 0000000000016d93 RDI: 0000000000000003
RBP: ffffc900040f70b0 R08: ffff8880588aa5d3 R09: 1ffff1100b1154ba
R10: dffffc0000000000 R11: ffffed100b1154bb R12: 0000000000000000
R13: 1ffff9200081edec R14: dffffc0000000000 R15: fffffffffffffffb
FS:  00007f65c05b86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc4962a038 CR3: 0000000021dad000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
   0:	8b 04 24             	mov    (%rsp),%eax
   3:	89 18                	mov    %ebx,(%rax)
   5:	89 9c 24 38 01 00 00 	mov    %ebx,0x138(%rsp)
   c:	4c 8b 7c 24 10       	mov    0x10(%rsp),%r15
  11:	4d 85 ff             	test   %r15,%r15
  14:	0f 84 bd 00 00 00    	je     0xd7
  1a:	e8 78 dc 58 ff       	call   0xff58dc97
  1f:	49 8d 7f 08          	lea    0x8(%r15),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 30       	movzbl (%rax,%r14,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 3d 1e 00 00    	jne    0x1e74
  37:	41 0f b7 47 08       	movzwl 0x8(%r15),%eax
  3c:	c1 e0 04             	shl    $0x4,%eax
  3f:	48                   	rex.W