On Fri, Mar 01, 2019 at 11:05:05PM -0800, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 42fd8df9d1d9 Add linux-next specific files for 20190228 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=16c3cd5cc00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c0f38652d28b522f > dashboard link: https://syzkaller.appspot.com/bug?extid=cc252aa9d2d3b576246f > 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+cc252aa9d2d3b576246f@xxxxxxxxxxxxxxxxxxxxxxxxx > > page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0) > page->mem_cgroup:ffff888059786cc0 > ------------[ cut here ]------------ > kernel BUG at include/linux/mm.h:579! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 22405 Comm: syz-executor.3 Not tainted 5.0.0-rc8-next-20190228 > #45 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:put_page_testzero include/linux/mm.h:579 [inline] > RIP: 0010:put_page include/linux/mm.h:1025 [inline] > RIP: 0010:generic_pipe_buf_release+0x120/0x160 fs/pipe.c:224 > Code: bd ff 4c 89 e7 e8 90 43 db ff e8 5b 07 bd ff 5b 41 5c 41 5d 5d c3 e8 > 4f 07 bd ff 48 c7 c6 60 98 75 87 4c 89 e7 e8 c0 db e4 ff <0f> 0b e8 39 07 bd > ff 4d 8d 65 ff e9 3d ff ff ff 48 89 df e8 e8 f8 > RSP: 0018:ffff888056c57920 EFLAGS: 00010246 > RAX: 0000000000040000 RBX: ffffea0002283db4 RCX: ffffc9000c456000 > RDX: 0000000000040000 RSI: ffffffff81984e72 RDI: ffffed100ad8af08 > RBP: ffff888056c57938 R08: 0000000000000021 R09: ffffed1015d05011 > R10: ffffed1015d05010 R11: ffff8880ae828087 R12: ffffea0002283d80 > R13: 0000000000000000 R14: ffff88809ad3c800 R15: ffff8880592ac928 > FS: 00007fb53aaf2700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fff65e0fdb8 CR3: 0000000093a2f000 CR4: 00000000001406f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > pipe_buf_release include/linux/pipe_fs_i.h:129 [inline] > iter_file_splice_write+0x7d1/0xbe0 fs/splice.c:759 > do_splice_from fs/splice.c:847 [inline] > direct_splice_actor+0x126/0x1a0 fs/splice.c:1019 > splice_direct_to_actor+0x369/0x970 fs/splice.c:974 > do_splice_direct+0x1da/0x2a0 fs/splice.c:1062 > do_sendfile+0x597/0xd00 fs/read_write.c:1442 > __do_sys_sendfile64 fs/read_write.c:1503 [inline] > __se_sys_sendfile64 fs/read_write.c:1489 [inline] > __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1489 > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x457e29 > Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fb53aaf1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 > RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457e29 > RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003 > RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000102000000 R11: 0000000000000246 R12: 00007fb53aaf26d4 > R13: 00000000004c4dce R14: 00000000004d8af8 R15: 00000000ffffffff > Modules linked in: > ---[ end trace ce17ea3937b628f2 ]--- > RIP: 0010:put_page_testzero include/linux/mm.h:579 [inline] > RIP: 0010:put_page include/linux/mm.h:1025 [inline] > RIP: 0010:generic_pipe_buf_release+0x120/0x160 fs/pipe.c:224 > Code: bd ff 4c 89 e7 e8 90 43 db ff e8 5b 07 bd ff 5b 41 5c 41 5d 5d c3 e8 > 4f 07 bd ff 48 c7 c6 60 98 75 87 4c 89 e7 e8 c0 db e4 ff <0f> 0b e8 39 07 bd > ff 4d 8d 65 ff e9 3d ff ff ff 48 89 df e8 e8 f8 > RSP: 0018:ffff888056c57920 EFLAGS: 00010246 > RAX: 0000000000040000 RBX: ffffea0002283db4 RCX: ffffc9000c456000 > RDX: 0000000000040000 RSI: ffffffff81984e72 RDI: ffffed100ad8af08 > RBP: ffff888056c57938 R08: 0000000000000021 R09: ffffed1015d05011 > R10: ffffed1015d05010 R11: ffff8880ae828087 R12: ffffea0002283d80 > R13: 0000000000000000 R14: ffff88809ad3c800 R15: ffff8880592ac928 > FS: 00007fb53aaf2700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b30225000 CR3: 0000000093a2f000 CR4: 00000000001406e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > 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#bug-status-tracking for how to communicate with > syzbot. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000009af83005831724a4%40google.com. > For more options, visit https://groups.google.com/d/optout. Well it's probably the same as this: https://groups.google.com/forum/#!topic/syzkaller-bugs/GTzYqK1FaPI, just reported a day too late as it was already fixed in next-20190301 by the change folded into "block: introduce mp_bvec_for_each_page() for iterating over page". #syz invalid Also Dmitry, I thought that syzbot is only supposed to report bugs on linux-next when they have a reproducer? - Eric
