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: 698 Comm: syz-executor.0 Not tainted 5.10.237-syzkaller-1007474-gcf6ed0f1511d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:ext4_split_extent_at+0xaea/0xe90 fs/ext4/extents.c:3279 Code: 89 de e8 89 a3 99 ff 85 db 74 0f e8 d0 9f 99 ff 4c 8b 64 24 38 e9 f0 fa ff ff 48 8b 4c 24 10 48 8d 79 04 48 89 f8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 48 8b 5c 24 38 0f 85 a3 02 00 00 48 8b 84 24 RSP: 0018:ffffc90001966f80 EFLAGS: 00010247 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88811ab8cf00 RSI: 0000000000000000 RDI: 0000000000000004 RBP: ffffc900019670f0 R08: 0000000000000004 R09: 0000000000000003 R10: fffff5200032cd14 R11: 1ffff9200032cd14 R12: 000000000000002a R13: 1ffff9200032ce0c R14: ffff888121348198 R15: dffffc0000000000 FS: 00007fd2368ef6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020029000 CR3: 0000000119e83000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_split_extent+0x1d7/0x4e0 fs/ext4/extents.c:3348 ext4_split_convert_extents fs/ext4/extents.c:3708 [inline] ext4_ext_handle_unwritten_extents fs/ext4/extents.c:3869 [inline] ext4_ext_map_blocks+0x1b38/0x5d40 fs/ext4/extents.c:4224 ext4_map_blocks+0x978/0x1bc0 fs/ext4/inode.c:674 ext4_iomap_alloc fs/ext4/inode.c:3518 [inline] ext4_iomap_begin+0x6bb/0x910 fs/ext4/inode.c:3568 iomap_apply+0x115/0x6a0 fs/iomap/apply.c:46 __iomap_dio_rw+0x7ad/0x1110 fs/iomap/direct-io.c:527 iomap_dio_rw+0x35/0x80 fs/iomap/direct-io.c:615 ext4_dio_write_iter fs/ext4/file.c:573 [inline] ext4_file_write_iter+0xdbe/0x1980 fs/ext4/file.c:683 call_write_iter include/linux/fs.h:2058 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x725/0xd60 fs/read_write.c:605 ksys_write+0x140/0x240 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:667 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fd23f14d959 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd2368ef0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd23f26d050 RCX: 00007fd23f14d959 RDX: 0000000000000012 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00007fd23f1a9c88 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fd23f26d050 R15: 00007fff8b2e61b8 Modules linked in: ---[ end trace 1fc9b1d905361461 ]--- RIP: 0010:ext4_split_extent_at+0xaea/0xe90 fs/ext4/extents.c:3279 Code: 89 de e8 89 a3 99 ff 85 db 74 0f e8 d0 9f 99 ff 4c 8b 64 24 38 e9 f0 fa ff ff 48 8b 4c 24 10 48 8d 79 04 48 89 f8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 48 8b 5c 24 38 0f 85 a3 02 00 00 48 8b 84 24 RSP: 0018:ffffc90001966f80 EFLAGS: 00010247 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88811ab8cf00 RSI: 0000000000000000 RDI: 0000000000000004 RBP: ffffc900019670f0 R08: 0000000000000004 R09: 0000000000000003 R10: fffff5200032cd14 R11: 1ffff9200032cd14 R12: 000000000000002a R13: 1ffff9200032ce0c R14: ffff888121348198 R15: dffffc0000000000 FS: 00007fd2368ef6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002003f000 CR3: 0000000119e83000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 89 de mov %ebx,%esi 2: e8 89 a3 99 ff call 0xff99a390 7: 85 db test %ebx,%ebx 9: 74 0f je 0x1a b: e8 d0 9f 99 ff call 0xff999fe0 10: 4c 8b 64 24 38 mov 0x38(%rsp),%r12 15: e9 f0 fa ff ff jmp 0xfffffb0a 1a: 48 8b 4c 24 10 mov 0x10(%rsp),%rcx 1f: 48 8d 79 04 lea 0x4(%rcx),%rdi 23: 48 89 f8 mov %rdi,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 48 8b 5c 24 38 mov 0x38(%rsp),%rbx 36: 0f 85 a3 02 00 00 jne 0x2df 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 84 .byte 0x84 3f: 24 .byte 0x24