general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 0 PID: 32766 Comm: kworker/u4:2 Not tainted 5.10.194-syzkaller-00508-ga27512601c2d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Workqueue: writeback wb_workfn (flush-7:1) RIP: 0010:write_inode fs/fs-writeback.c:1327 [inline] RIP: 0010:__writeback_single_inode+0x438/0xac0 fs/fs-writeback.c:1527 Code: 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 80 18 eb ff 48 8b 1b 48 83 c3 20 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 5a 18 eb ff 48 83 3b 00 74 26 4c 89 RSP: 0018:ffffc90009c375b8 EFLAGS: 00010202 RAX: 0000000000000004 RBX: 0000000000000020 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90009c37610 R08: ffffffff81bcdbdc R09: 0000000000000003 R10: fffff52001386ea8 R11: dffffc0000000001 R12: 1ffff1102c6cedb3 R13: ffff888163676d70 R14: ffff888163676df8 R15: ffff888163676d98 FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f79d246bd00 CR3: 000000011ce48000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: writeback_sb_inodes+0x99c/0x16b0 fs/fs-writeback.c:1733 __writeback_inodes_wb fs/fs-writeback.c:1804 [inline] wb_writeback+0x4b7/0xc60 fs/fs-writeback.c:1910 wb_check_old_data_flush fs/fs-writeback.c:2012 [inline] wb_do_writeback fs/fs-writeback.c:2065 [inline] wb_workfn+0xb3d/0x1110 fs/fs-writeback.c:2094 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447 kthread+0x34b/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:299 Modules linked in: ---[ end trace eaf927b2005d7851 ]--- RIP: 0010:write_inode fs/fs-writeback.c:1327 [inline] RIP: 0010:__writeback_single_inode+0x438/0xac0 fs/fs-writeback.c:1527 Code: 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 80 18 eb ff 48 8b 1b 48 83 c3 20 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 5a 18 eb ff 48 83 3b 00 74 26 4c 89 RSP: 0018:ffffc90009c375b8 EFLAGS: 00010202 RAX: 0000000000000004 RBX: 0000000000000020 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90009c37610 R08: ffffffff81bcdbdc R09: 0000000000000003 R10: fffff52001386ea8 R11: dffffc0000000001 R12: 1ffff1102c6cedb3 R13: ffff888163676d70 R14: ffff888163676df8 R15: ffff888163676d98 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1838f2988 CR3: 00000001578d0000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) 4: 74 08 je 0xe 6: 48 89 df mov %rbx,%rdi 9: e8 80 18 eb ff call 0xffeb188e e: 48 8b 1b mov (%rbx),%rbx 11: 48 83 c3 20 add $0x20,%rbx 15: 48 89 d8 mov %rbx,%rax 18: 48 c1 e8 03 shr $0x3,%rax 1c: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 23: fc ff df * 26: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2a: 74 08 je 0x34 2c: 48 89 df mov %rbx,%rdi 2f: e8 5a 18 eb ff call 0xffeb188e 34: 48 83 3b 00 cmpq $0x0,(%rbx) 38: 74 26 je 0x60 3a: 4c rex.WR 3b: 89 .byte 0x89