On Fri, 2018-11-16 at 12:40 -0800, Dmitry Vyukov wrote: > On Tue, Nov 6, 2018 at 9:03 PM, syzbot > <syzbot+1818cd833edc063452c6@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: d881de30d29e Add linux-next specific files for 20181107 > > git tree: linux-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=14aa485d400000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=caa433e1c8778437 > > dashboard link: https://syzkaller.appspot.com/bug?extid=1818cd833edc063452c6 > > compiler: gcc (GCC) 8.0.1 20180413 (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+1818cd833edc063452c6@xxxxxxxxxxxxxxxxxxxxxxxxx > > This is another manifestation of the following report, right? > > #syz dup: KASAN: use-after-free Read in locks_delete_block > Slightly different manifestation in this case, but the same bug, yes. > > ================================================================== > > BUG: KASAN: stack-out-of-bounds in locks_remove_flock+0x33c/0x350 > > fs/locks.c:2567 > > Read of size 8 at addr ffff8801c71c7a08 by task syz-executor5/20562 > > > > CPU: 0 PID: 20562 Comm: syz-executor5 Not tainted 4.20.0-rc1-next-20181107+ > > #107 > > 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+0x244/0x39d lib/dump_stack.c:113 > > print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 > > kasan_report_error mm/kasan/report.c:354 [inline] > > kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 > > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > > locks_remove_flock+0x33c/0x350 fs/locks.c:2567 > > locks_remove_file+0x148/0x5c0 fs/locks.c:2607 > > __fput+0x2f0/0xa70 fs/file_table.c:271 > > ____fput+0x15/0x20 fs/file_table.c:312 > > task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 > > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > > exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 > > prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] > > syscall_return_slowpath arch/x86/entry/common.c:268 [inline] > > do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > RIP: 0033:0x411021 > > Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 34 19 00 00 c3 48 > > 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 > > c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 > > RSP: 002b:00007ffdb42509a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 > > RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000411021 > > RDX: 0000000000000000 RSI: 0000000000732ea0 RDI: 0000000000000004 > > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > > R10: 00007ffdb42508c0 R11: 0000000000000293 R12: 0000000000000000 > > R13: 0000000000000001 R14: 0000000000000201 R15: 0000000000000005 > > > > The buggy address belongs to the page: > > page:ffffea00071c71c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 > > flags: 0x2fffc0000000000() > > raw: 02fffc0000000000 0000000000000000 ffffffff071c0101 0000000000000000 > > raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 > > page dumped because: kasan: bad access detected > > > > Memory state around the buggy address: > > ffff8801c71c7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > ffff8801c71c7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > > > > > ffff8801c71c7a00: f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00 00 > > > > ^ > > ffff8801c71c7a80: 00 f1 f1 f1 f1 00 00 f2 f2 f2 f2 f2 f2 f8 f2 f2 > > ffff8801c71c7b00: f2 f2 f2 f2 f2 00 f2 f2 f2 00 00 00 00 00 00 00 > > ================================================================== > > > > > > --- > > 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/00000000000082cc8d057a0c0877%40google.com. > > For more options, visit https://groups.google.com/d/optout. -- Jeff Layton <jlayton@xxxxxxxxxx>
