EXT4-fs (loop1): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w 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: 6177 Comm: syz.1.124 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+0x2d04/0x6800 fs/ext4/extents.c:4498 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 c7 e0 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:ffffc9000be06c20 EFLAGS: 00010246 RAX: 0000000000000000 RBX: fffffffffffffffb RCX: 0000000000080000 RDX: ffffc9000c059000 RSI: 000000000007661d RDI: 0000000000000003 RBP: ffffc9000be06ed0 R08: ffffffff911c559f R09: 1ffffffff2238ab3 R10: dffffc0000000000 R11: fffffbfff2238ab4 R12: 0000000000000001 R13: 1ffff920017c0db0 R14: dffffc0000000000 R15: fffffffffffffffb FS: 00007f6ee2bcd6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6ee1de9f00 CR3: 000000007af85000 CR4: 00000000003506e0 Call Trace: ext4_map_blocks+0x9e2/0x1b80 fs/ext4/inode.c:654 ext4_iomap_alloc fs/ext4/inode.c:3362 [inline] ext4_iomap_begin+0x806/0xb10 fs/ext4/inode.c:3412 iomap_iter+0x6b1/0xec0 fs/iomap/iter.c:91 __iomap_dio_rw+0xc72/0x1d20 fs/iomap/direct-io.c:673 iomap_dio_rw+0x45/0xa0 fs/iomap/direct-io.c:763 ext4_dio_write_iter fs/ext4/file.c:577 [inline] ext4_file_write_iter+0x13fb/0x1880 fs/ext4/file.c:696 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x738/0xc30 fs/read_write.c:860 iter_file_splice_write+0x6a3/0xcb0 fs/splice.c:736 do_splice_from fs/splice.c:933 [inline] direct_splice_actor+0xe8/0x130 fs/splice.c:1142 splice_direct_to_actor+0x304/0x8c0 fs/splice.c:1088 do_splice_direct+0x1d5/0x2f0 fs/splice.c:1194 do_sendfile+0x5f2/0xef0 fs/read_write.c:1254 __do_sys_sendfile64 fs/read_write.c:1322 [inline] __se_sys_sendfile64+0x145/0x1a0 fs/read_write.c:1308 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: 0033:0x7f6ee1d9c819 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:00007f6ee2bcd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f6ee2015fa0 RCX: 00007f6ee1d9c819 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 00007f6ee1e32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000800000009 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6ee2016038 R14: 00007f6ee2015fa0 R15: 00007ffc8c3c60d8 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+0x2d04/0x6800 fs/ext4/extents.c:4498 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 c7 e0 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:ffffc9000be06c20 EFLAGS: 00010246 RAX: 0000000000000000 RBX: fffffffffffffffb RCX: 0000000000080000 RDX: ffffc9000c059000 RSI: 000000000007661d RDI: 0000000000000003 RBP: ffffc9000be06ed0 R08: ffffffff911c559f R09: 1ffffffff2238ab3 R10: dffffc0000000000 R11: fffffbfff2238ab4 R12: 0000000000000001 R13: 1ffff920017c0db0 R14: dffffc0000000000 R15: fffffffffffffffb FS: 00007f6ee2bcd6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f09feb41000 CR3: 000000007af85000 CR4: 00000000003506f0 ---------------- 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 c7 e0 58 ff call 0xff58e0e6 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