Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 0 UID: 0 PID: 5328 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:bfs_move_block fs/bfs/file.c:43 [inline] RIP: 0010:bfs_move_blocks fs/bfs/file.c:57 [inline] RIP: 0010:bfs_get_block+0x589/0xae0 fs/bfs/file.c:126 Code: f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 50 79 86 ff 49 8b 5d 20 4d 8d 66 28 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 48 8b 6c 24 18 74 08 4c 89 e7 e8 24 79 86 ff 4c 89 ef RSP: 0000:ffffc9000ef56418 EFLAGS: 00010206 RAX: 0000000000000005 RBX: 0000000000000200 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff88801a8512d8 RBP: ffff88801cc2e7b8 R08: ffffea000141d9b7 R09: 1ffffd4000283b36 R10: dffffc0000000000 R11: fffff94000283b37 R12: 0000000000000028 R13: ffff88801a8512b8 R14: 0000000000000000 R15: 0000000000000022 FS: 00007fac97ba76c0(0000) GS:ffff88808ca49000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3f2f9909c0 CR3: 0000000011f88000 CR4: 0000000000352ef0 Call Trace: __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2142 block_write_begin+0x8d/0x120 fs/buffer.c:2253 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:180 generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4319 generic_file_write_iter+0x14a/0x680 mm/filemap.c:4462 __kernel_write_iter+0x41e/0x880 fs/read_write.c:621 __kernel_write+0x106/0x170 fs/read_write.c:641 __dump_emit fs/coredump.c:1221 [inline] dump_emit+0x8e9/0xab0 fs/coredump.c:1259 elf_core_dump+0x2e5d/0x3ad0 fs/binfmt_elf.c:2089 coredump_write+0x1216/0x1910 fs/coredump.c:1050 do_coredump fs/coredump.c:1127 [inline] vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 get_signal+0x1107/0x1330 kernel/signal.c:3019 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x176/0x620 kernel/entry/common.c:219 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fac96d9c821 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:00000000fffffeb0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fac97016090 RCX: 00007fac96d9c819 RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400 RBP: 00007fac96e32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fac97016128 R14: 00007fac97016090 R15: 00007ffe59b05358 Modules linked in: ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: f8 clc 1: 48 c1 e8 03 shr $0x3,%rax 5: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) a: 74 05 je 0x11 c: e8 50 79 86 ff call 0xff867961 11: 49 8b 5d 20 mov 0x20(%r13),%rbx 15: 4d 8d 66 28 lea 0x28(%r14),%r12 19: 4c 89 e0 mov %r12,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 48 8b 6c 24 18 mov 0x18(%rsp),%rbp 33: 74 08 je 0x3d 35: 4c 89 e7 mov %r12,%rdi 38: e8 24 79 86 ff call 0xff867961 3d: 4c 89 ef mov %r13,%rdi