EXT4-fs error (device loop0) in ext4_reserve_inode_write:5931: IO failure
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: 317 Comm: syz.0.6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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+0x2e4c/0x6200 fs/ext4/extents.c:4497
Code: 1a 00 00 48 8b 04 24 89 18 4c 8b b4 24 40 01 00 00 4d 85 f6 0f 84 bc 00 00 00 48 89 5c 24 20 49 8d 7e 08 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 38 16 00 00 41 0f b7 46 08 c1 e0 04 48
RSP: 0018:ffffc9000dce6fa0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc90001299000 RSI: 000000000002afb5 RDI: 0000000000000003
RBP: ffffc9000dce7250 R08: ffff88810b5be3ab R09: 1ffff110216b7c75
R10: dffffc0000000000 R11: ffffed10216b7c76 R12: dffffc0000000000
R13: 1ffff92001b9ce20 R14: fffffffffffffffb R15: 0000000000000010
FS:  00007f556fa536c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000d1030 CR3: 0000000132e26000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ext4_map_blocks+0x9d8/0x1b70 fs/ext4/inode.c:679
 _ext4_get_block+0x1ea/0x540 fs/ext4/inode.c:822
 ext4_get_block+0x39/0x50 fs/ext4/inode.c:839
 ext4_block_write_begin+0x594/0x1280 fs/ext4/inode.c:1124
 ext4_write_begin+0x600/0xf90 fs/ext4/ext4_jbd2.h:-1
 ext4_da_write_begin+0x3e7/0x8c0 fs/ext4/inode.c:3001
 generic_perform_write+0x32d/0x740 mm/filemap.c:3913
 ext4_buffered_write_iter+0x367/0x630 fs/ext4/file.c:285
 ext4_file_write_iter+0x191/0x1500 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2282 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x603/0xce0 fs/read_write.c:584
 ksys_write+0x149/0x250 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:646
 x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 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: 0033:0x7f556eb9cdd9
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:00007f556fa53028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f556ee15fa0 RCX: 00007f556eb9cdd9
RDX: 00000000000000c8 RSI: 0000200000000380 RDI: 0000000000000005
RBP: 00007f556ec32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f556ee16038 R14: 00007f556ee15fa0 R15: 00007ffe80815c88
 </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+0x2e4c/0x6200 fs/ext4/extents.c:4497
Code: 1a 00 00 48 8b 04 24 89 18 4c 8b b4 24 40 01 00 00 4d 85 f6 0f 84 bc 00 00 00 48 89 5c 24 20 49 8d 7e 08 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 38 16 00 00 41 0f b7 46 08 c1 e0 04 48
RSP: 0018:ffffc9000dce6fa0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc90001299000 RSI: 000000000002afb5 RDI: 0000000000000003
RBP: ffffc9000dce7250 R08: ffff88810b5be3ab R09: 1ffff110216b7c75
R10: dffffc0000000000 R11: ffffed10216b7c76 R12: dffffc0000000000
R13: 1ffff92001b9ce20 R14: fffffffffffffffb R15: 0000000000000010
FS:  00007f556fa536c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e90dff8 CR3: 0000000132e26000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	1a 00                	sbb    (%rax),%al
   2:	00 48 8b             	add    %cl,-0x75(%rax)
   5:	04 24                	add    $0x24,%al
   7:	89 18                	mov    %ebx,(%rax)
   9:	4c 8b b4 24 40 01 00 	mov    0x140(%rsp),%r14
  10:	00
  11:	4d 85 f6             	test   %r14,%r14
  14:	0f 84 bc 00 00 00    	je     0xd6
  1a:	48 89 5c 24 20       	mov    %rbx,0x20(%rsp)
  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 38 16 00 00    	jne    0x166f
  37:	41 0f b7 46 08       	movzwl 0x8(%r14),%eax
  3c:	c1 e0 04             	shl    $0x4,%eax
  3f:	48                   	rex.W