Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] CPU: 0 UID: 0 PID: 7369 Comm: syz.0.496 Not tainted 6.12.0-rc4-syzkaller-00256-gc71f8fb4dc91 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 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+0xa75/0xb70 fs/bfs/file.c:126 Code: 00 41 8b 0f b8 77 7f ff ff 21 c1 81 c9 08 80 00 00 4c 89 ef 4c 89 f6 e8 29 14 a0 ff 49 89 c5 48 8d 68 28 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 ef e8 6c 7b 7b ff 4c 8b 75 00 48 8d 7b RSP: 0018:ffffc9000d36ec50 EFLAGS: 00010206 RAX: 0000000000000005 RBX: ffff888045ebdae0 RCX: ffff88801fa40000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000028 R08: ffffffff822344c7 R09: 1ffffd40002594b6 R10: dffffc0000000000 R11: fffff940002594b7 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000043 R15: ffff888031cfce68 FS: 0000555581ad0500(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020007000 CR3: 0000000044902000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2121 block_write_begin+0x8f/0x120 fs/buffer.c:2231 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:179 generic_perform_write+0x344/0x6d0 mm/filemap.c:4054 generic_file_write_iter+0xae/0x310 mm/filemap.c:4181 __kernel_write_iter+0x42a/0x940 fs/read_write.c:616 __kernel_write+0x120/0x180 fs/read_write.c:636 __dump_emit+0x237/0x360 fs/coredump.c:807 elf_core_dump+0x360a/0x4770 fs/binfmt_elf.c:2100 do_coredump+0x2162/0x2ec0 fs/coredump.c:758 get_signal+0x13fc/0x1740 kernel/signal.c:2902 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x79/0x280 kernel/entry/common.c:231 exc_page_fault+0x590/0x8c0 arch/x86/mm/fault.c:1542 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7ff939d7e721 Code: 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:ffffffffffffffe0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007ff939f35f80 RCX: 00007ff939d7e719 RDX: 0000000000000000 RSI: ffffffffffffffe0 RDI: 0000000004008011 RBP: 00007ff939df132e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ff939f35f80 R14: 00007ff939f35f80 R15: 000000000000130d Modules linked in: ---[ end trace 0000000000000000 ]--- 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+0xa75/0xb70 fs/bfs/file.c:126 Code: 00 41 8b 0f b8 77 7f ff ff 21 c1 81 c9 08 80 00 00 4c 89 ef 4c 89 f6 e8 29 14 a0 ff 49 89 c5 48 8d 68 28 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 ef e8 6c 7b 7b ff 4c 8b 75 00 48 8d 7b RSP: 0018:ffffc9000d36ec50 EFLAGS: 00010206 RAX: 0000000000000005 RBX: ffff888045ebdae0 RCX: ffff88801fa40000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000028 R08: ffffffff822344c7 R09: 1ffffd40002594b6 R10: dffffc0000000000 R11: fffff940002594b7 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000043 R15: ffff888031cfce68 FS: 0000555581ad0500(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020007000 CR3: 0000000044902000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 41 8b 0f mov (%r15),%ecx 3: b8 77 7f ff ff mov $0xffff7f77,%eax 8: 21 c1 and %eax,%ecx a: 81 c9 08 80 00 00 or $0x8008,%ecx 10: 4c 89 ef mov %r13,%rdi 13: 4c 89 f6 mov %r14,%rsi 16: e8 29 14 a0 ff call 0xffa01444 1b: 49 89 c5 mov %rax,%r13 1e: 48 8d 68 28 lea 0x28(%rax),%rbp 22: 48 89 e8 mov %rbp,%rax 25: 48 c1 e8 03 shr $0x3,%rax * 29: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 48 89 ef mov %rbp,%rdi 33: e8 6c 7b 7b ff call 0xff7b7ba4 38: 4c 8b 75 00 mov 0x0(%rbp),%r14 3c: 48 rex.W 3d: 8d .byte 0x8d 3e: 7b .byte 0x7b