EXT4-fs: Ignoring removed nobh option
EXT4-fs: Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE
EXT4-fs (loop3): mounted filesystem without journal. Quota mode: none.
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: 8518 Comm: syz.3.1358 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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+0x3620/0x6870 fs/ext4/extents.c:4497
Code: 24 10 02 00 00 8b 44 24 48 48 89 44 24 18 4c 8b b4 24 60 01 00 00 4d 85 f6 0f 84 b2 00 00 00 49 8d 7e 08 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 aa 12 00 00 41 0f b7 46 08 c1 e0 04 48
RSP: 0018:ffffc900057e6a40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880422f0cb8 RCX: 0000000000080000
RDX: ffffc9000cd09000 RSI: 0000000000017f27 RDI: 0000000000000003
RBP: ffffc900057e6d10 R08: ffff88804222a403 R09: 1ffff11008445480
R10: dffffc0000000000 R11: ffffed1008445481 R12: dffffc0000000000
R13: 1ffff92000afcd78 R14: fffffffffffffffb R15: 0000000000000010
FS:  00007fc3f545d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fd11ff8 CR3: 000000001cb9e000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 ext4_map_blocks+0x9de/0x1b70 fs/ext4/inode.c:679
 _ext4_get_block+0x1e7/0x540 fs/ext4/inode.c:822
 ext4_get_block_unwritten+0x2a/0x100 fs/ext4/inode.c:855
 ext4_block_write_begin+0x644/0x1300 fs/ext4/inode.c:1124
 ext4_write_begin+0x629/0xf80 fs/ext4/ext4_jbd2.h:-1
 ext4_da_write_begin+0x30a/0x960 fs/ext4/inode.c:3000
 generic_perform_write+0x2fa/0x5c0 mm/filemap.c:3862
 ext4_buffered_write_iter+0x11a/0x390 fs/ext4/file.c:285
 ext4_file_write_iter+0x1cf/0x1710 fs/ext4/file.c:-1
 do_iter_readv_writev fs/read_write.c:-1 [inline]
 do_iter_write+0x642/0xb10 fs/read_write.c:861
 iter_file_splice_write+0x699/0xcc0 fs/splice.c:685
 do_splice_from fs/splice.c:763 [inline]
 direct_splice_actor+0xe1/0x130 fs/splice.c:950
 splice_direct_to_actor+0x48b/0xb90 fs/splice.c:896
 do_splice_direct+0x1ce/0x2f0 fs/splice.c:1002
 do_sendfile+0x5f3/0xea0 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64+0x141/0x1a0 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc3f459c819
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:00007fc3f545d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fc3f4815fa0 RCX: 00007fc3f459c819
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005
RBP: 00007fc3f4632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0002000000000006 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc3f4816038 R14: 00007fc3f4815fa0 R15: 00007ffdf2d4da18
 </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+0x3620/0x6870 fs/ext4/extents.c:4497
Code: 24 10 02 00 00 8b 44 24 48 48 89 44 24 18 4c 8b b4 24 60 01 00 00 4d 85 f6 0f 84 b2 00 00 00 49 8d 7e 08 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 aa 12 00 00 41 0f b7 46 08 c1 e0 04 48
RSP: 0018:ffffc900057e6a40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880422f0cb8 RCX: 0000000000080000
RDX: ffffc9000cd09000 RSI: 0000000000017f27 RDI: 0000000000000003
RBP: ffffc900057e6d10 R08: ffff88804222a403 R09: 1ffff11008445480
R10: dffffc0000000000 R11: ffffed1008445481 R12: dffffc0000000000
R13: 1ffff92000afcd78 R14: fffffffffffffffb R15: 0000000000000010
FS:  00007fc3f545d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd30c706d58 CR3: 000000001cb9e000 CR4: 00000000003506e0
----------------
Code disassembly (best guess):
   0:	24 10                	and    $0x10,%al
   2:	02 00                	add    (%rax),%al
   4:	00 8b 44 24 48 48    	add    %cl,0x48482444(%rbx)
   a:	89 44 24 18          	mov    %eax,0x18(%rsp)
   e:	4c 8b b4 24 60 01 00 	mov    0x160(%rsp),%r14
  15:	00
  16:	4d 85 f6             	test   %r14,%r14
  19:	0f 84 b2 00 00 00    	je     0xd1
  1f:	49 8d 7e 08          	lea    0x8(%r14),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 aa 12 00 00    	jne    0x12e1
  37:	41 0f b7 46 08       	movzwl 0x8(%r14),%eax
  3c:	c1 e0 04             	shl    $0x4,%eax
  3f:	48                   	rex.W