On 11/29/19 9:19 AM, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 089cf7f6 Linux 5.3-rc7 Ugh, why test previous cycle's rc7 now? Typo for 5.4? > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1210a761600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=b89bb446a3faaba4 > dashboard link: https://syzkaller.appspot.com/bug?extid=fe601f9e887449d40112 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+fe601f9e887449d40112@xxxxxxxxxxxxxxxxxxxxxxxxx > > WARNING: CPU: 0 PID: 12560 at mm/filemap.c:220 > unaccount_page_cache_page+0x65b/0xda0 mm/filemap.c:220 That's this warning: /* * At this point page must be either written or cleaned by * truncate. Dirty page here signals a bug and loss of * unwritten data. * * This fixes dirty accounting after removing the page entirely * but leaves PageDirty set: it has no effect for truncated * page and anyway will be cleared before returning page into * buddy allocator. */ if (WARN_ON_ONCE(PageDirty(page))) account_page_cleaned(page, mapping, inode_to_wb(mapping->host)); CC Jan > Kernel panic - not syncing: panic_on_warn set ... > CPU: 0 PID: 12560 Comm: syz-executor.2 Not tainted 5.3.0-rc7 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x172/0x1f0 lib/dump_stack.c:113 > panic+0x2dc/0x755 kernel/panic.c:219 > __warn.cold+0x20/0x4c kernel/panic.c:576 > report_bug+0x263/0x2b0 lib/bug.c:186 > fixup_bug arch/x86/kernel/traps.c:179 [inline] > fixup_bug arch/x86/kernel/traps.c:174 [inline] > do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 > do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291 > invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 > RIP: 0010:unaccount_page_cache_page+0x65b/0xda0 mm/filemap.c:220 > Code: 00 0f 85 be 06 00 00 49 8b 5d 00 31 ff 48 c1 eb 03 83 e3 01 48 89 de > e8 c3 25 e4 ff 48 85 db 0f 84 c0 fb ff ff e8 15 24 e4 ff <0f> 0b 48 b8 00 > 00 00 00 00 fc ff df 48 8b 55 d0 48 c1 ea 03 80 3c > RSP: 0018:ffff888060b7f9b8 EFLAGS: 00010016 > RAX: 0000000000040000 RBX: 0000000000000001 RCX: ffffc9000a781000 > RDX: 0000000000001dcb RSI: ffffffff818e513b RDI: 0000000000000007 > RBP: ffff888060b7f9f8 R08: ffff8880584de400 R09: fffff940003f9169 > R10: fffff940003f9168 R11: ffffea0001fc8b47 R12: ffffea0001fc8b40 > R13: ffffea0001fc8b40 R14: ffffea0001fc8b40 R15: ffffea0001fc8b88 > delete_from_page_cache_batch+0x1e9/0x1170 mm/filemap.c:350 > truncate_inode_pages_range+0x622/0x1740 mm/truncate.c:366 > blkdev_fallocate+0x23a/0x410 fs/block_dev.c:2081 > vfs_fallocate+0x4aa/0xa50 fs/open.c:309 > ksys_fallocate+0x58/0xa0 fs/open.c:332 > __do_sys_fallocate fs/open.c:340 [inline] > __se_sys_fallocate fs/open.c:338 [inline] > __x64_sys_fallocate+0x97/0xf0 fs/open.c:338 > do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x459879 > Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fd75e4bfc78 EFLAGS: 00000246 ORIG_RAX: 000000000000011d > RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459879 > RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000004 > RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 > R10: 00000000369e5d84 R11: 0000000000000246 R12: 00007fd75e4c06d4 > R13: 00000000004bffbd R14: 00000000004d1fc0 R15: 00000000ffffffff > Shutting down cpus with NMI > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > --- > This bug 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 bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. >
