Hello, syzbot found the following issue on: HEAD commit: 4aa1da8d9972 Add linux-next specific files for 20230417 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=13b08dc0280000 kernel config: https://syzkaller.appspot.com/x/.config?x=3e1a2e42c883f5b6 dashboard link: https://syzkaller.appspot.com/bug?extid=d1ae544e6e9dc29bcba5 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/0beda3b66b40/disk-4aa1da8d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a7cd9f14ca57/vmlinux-4aa1da8d.xz kernel image: https://storage.googleapis.com/syzbot-assets/48453a9c6a60/bzImage-4aa1da8d.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d1ae544e6e9dc29bcba5@xxxxxxxxxxxxxxxxxxxxxxxxx RSP: 002b:00007f963cd4d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f963c1abf80 RCX: 00007f963c08c169 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 RBP: 00007f963cd4d1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000001dd03 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffd7ae18d4f R14: 00007f963cd4d300 R15: 0000000000022000 </TASK> general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 18742 Comm: syz-executor.5 Not tainted 6.3.0-rc7-next-20230417-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 RIP: 0010:folio_inode include/linux/pagemap.h:400 [inline] RIP: 0010:folio_wait_stable+0x23/0xe0 mm/page-writeback.c:3132 Code: 00 00 00 0f 1f 40 00 f3 0f 1e fa 55 48 89 fd 53 e8 a2 92 d1 ff 48 8d 7d 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a4 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b RSP: 0018:ffffc9000316f488 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: ffff88803e265cb0 RCX: ffffc9000c002000 RDX: 0000000000000001 RSI: ffffffff81b1f0ee RDI: 000000000000000c RBP: fffffffffffffff4 R08: 0000000000000001 R09: ffffffff8c8eef13 R10: fffffbfff191dde2 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88803e265ed8 R14: 0000000000002000 R15: ffff88803e265a50 FS: 00007f963cd4d700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f668b534110 CR3: 000000006ca4c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ext4_da_write_begin+0x47f/0x8b0 fs/ext4/inode.c:2939 generic_perform_write+0x256/0x570 mm/filemap.c:3927 ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:289 ext4_file_write_iter+0xbe0/0x1740 fs/ext4/file.c:710 call_write_iter include/linux/fs.h:1854 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x185/0x7e0 fs/read_write.c:860 vfs_iter_write+0x74/0xa0 fs/read_write.c:901 iter_file_splice_write+0x745/0xc80 fs/splice.c:761 do_splice_from fs/splice.c:839 [inline] direct_splice_actor+0x114/0x180 fs/splice.c:1018 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:973 do_splice_direct+0x1ab/0x280 fs/splice.c:1061 do_sendfile+0xb19/0x12c0 fs/read_write.c:1254 __do_sys_sendfile64 fs/read_write.c:1322 [inline] __se_sys_sendfile64 fs/read_write.c:1308 [inline] __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1308 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f963c08c169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f963cd4d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f963c1abf80 RCX: 00007f963c08c169 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 RBP: 00007f963cd4d1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000001dd03 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffd7ae18d4f R14: 00007f963cd4d300 R15: 0000000000022000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:folio_inode include/linux/pagemap.h:400 [inline] RIP: 0010:folio_wait_stable+0x23/0xe0 mm/page-writeback.c:3132 Code: 00 00 00 0f 1f 40 00 f3 0f 1e fa 55 48 89 fd 53 e8 a2 92 d1 ff 48 8d 7d 18 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a4 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b RSP: 0018:ffffc9000316f488 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: ffff88803e265cb0 RCX: ffffc9000c002000 RDX: 0000000000000001 RSI: ffffffff81b1f0ee RDI: 000000000000000c RBP: fffffffffffffff4 R08: 0000000000000001 R09: ffffffff8c8eef13 R10: fffffbfff191dde2 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88803e265ed8 R14: 0000000000002000 R15: ffff88803e265a50 FS: 00007f963cd4d700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32724000 CR3: 000000006ca4c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 00 add %al,(%rax) 2: 0f 1f 40 00 nopl 0x0(%rax) 6: f3 0f 1e fa endbr64 a: 55 push %rbp b: 48 89 fd mov %rdi,%rbp e: 53 push %rbx f: e8 a2 92 d1 ff callq 0xffd192b6 14: 48 8d 7d 18 lea 0x18(%rbp),%rdi 18: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1f: fc ff df 22: 48 89 fa mov %rdi,%rdx 25: 48 c1 ea 03 shr $0x3,%rdx * 29: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2d: 0f 85 a4 00 00 00 jne 0xd7 33: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 3a: fc ff df 3d: 48 rex.W 3e: 8b .byte 0x8b --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.