BUG: unable to handle page fault for address: ffffffffffffffec #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 7012067 P4D 7012067 PUD 7014067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1902 Comm: syz.2.494 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+0x2e59/0x6200 fs/ext4/extents.c:4497 Code: 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 8d 04 40 48 89 44 24 08 49 8d 46 28 48 RSP: 0018:ffffc90003abe720 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888119f21440 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffffffffec RBP: ffffc90003abe9d0 R08: ffff88813367fc33 R09: 1ffff110266cff86 R10: dffffc0000000000 R11: ffffed10266cff87 R12: dffffc0000000000 R13: 1ffff92000757d10 R14: ffffffffffffffe4 R15: 0000000000000010 FS: 000055556763b500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffec CR3: 0000000132ed3000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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 generic_perform_write+0x32d/0x740 mm/filemap.c:3914 ext4_buffered_write_iter+0x367/0x630 fs/ext4/file.c:285 ext4_file_write_iter+0x191/0x1500 fs/ext4/file.c:-1 __kernel_write_iter+0x296/0x660 fs/read_write.c:517 dump_emit_page fs/coredump.c:886 [inline] dump_user_range+0x40b/0x660 fs/coredump.c:913 elf_core_dump+0x2b52/0x3060 fs/binfmt_elf.c:2354 do_coredump+0x15d3/0x2240 fs/coredump.c:760 get_signal+0x11db/0x1520 kernel/signal.c:2877 arch_do_signal_or_restart+0xd1/0x1140 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:316 irqentry_exit+0x12/0x40 kernel/entry/common.c:419 exc_page_fault+0x5e/0xb0 arch/x86/mm/fault.c:1520 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f000e39ce61 Code: 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 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f000e615fa0 RCX: 00007f000e39ce59 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f000e432d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f000e615fac R14: 00007f000e615fa0 R15: 00007f000e615fa0 Modules linked in: CR2: ffffffffffffffec ---[ 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+0x2e59/0x6200 fs/ext4/extents.c:4497 Code: 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 8d 04 40 48 89 44 24 08 49 8d 46 28 48 RSP: 0018:ffffc90003abe720 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888119f21440 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffffffffec RBP: ffffc90003abe9d0 R08: ffff88813367fc33 R09: 1ffff110266cff86 R10: dffffc0000000000 R11: ffffed10266cff87 R12: dffffc0000000000 R13: 1ffff92000757d10 R14: ffffffffffffffe4 R15: 0000000000000010 FS: 000055556763b500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffec CR3: 0000000132ed3000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 40 01 00 rex add %eax,(%rax) 3: 00 4d 85 add %cl,-0x7b(%rbp) 6: f6 0f 84 testb $0x84,(%rdi) 9: bc 00 00 00 48 mov $0x48000000,%esp e: 89 5c 24 20 mov %ebx,0x20(%rsp) 12: 49 8d 7e 08 lea 0x8(%r14),%rdi 16: 48 89 f8 mov %rdi,%rax 19: 48 c1 e8 03 shr $0x3,%rax 1d: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax 22: 84 c0 test %al,%al 24: 0f 85 38 16 00 00 jne 0x1662 * 2a: 41 0f b7 46 08 movzwl 0x8(%r14),%eax <-- trapping instruction 2f: c1 e0 04 shl $0x4,%eax 32: 48 8d 04 40 lea (%rax,%rax,2),%rax 36: 48 89 44 24 08 mov %rax,0x8(%rsp) 3b: 49 8d 46 28 lea 0x28(%r14),%rax 3f: 48 rex.W