On Sun, Oct 13, 2019 at 11:09:09PM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 8ada228a Add linux-next specific files for 20191011 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=1423a87f600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=7cf4eed5fe42c31a > dashboard link: https://syzkaller.appspot.com/bug?extid=fb77e97ebf0612ee6914 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. Hm only thing that could go wrong is how we allocate the target for the user_copy, which is an argument directly from the ioctl parameter struct. Does syzbot not track that? We use the standard linux ioctl struct encoding in drm. Otherwise I have no idea why it can't create a reliable reproducer for this ... I'm also not seeing the bug, all the input validation we have seems correct :-/ -Daniel > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+fb77e97ebf0612ee6914@xxxxxxxxxxxxxxxxxxxxxxxxx > > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 30449 at include/linux/thread_info.h:150 > check_copy_size include/linux/thread_info.h:150 [inline] > WARNING: CPU: 1 PID: 30449 at include/linux/thread_info.h:150 copy_from_user > include/linux/uaccess.h:143 [inline] > WARNING: CPU: 1 PID: 30449 at include/linux/thread_info.h:150 > drm_mode_createblob_ioctl+0x398/0x490 drivers/gpu/drm/drm_property.c:800 > Kernel panic - not syncing: panic_on_warn set ... > CPU: 1 PID: 30449 Comm: syz-executor.5 Not tainted 5.4.0-rc2-next-20191011 > #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+0x2e3/0x75c kernel/panic.c:221 > __warn.cold+0x2f/0x35 kernel/panic.c:582 > report_bug+0x289/0x300 lib/bug.c:195 > fixup_bug arch/x86/kernel/traps.c:174 [inline] > fixup_bug arch/x86/kernel/traps.c:169 [inline] > do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 > do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 > invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 > RIP: 0010:check_copy_size include/linux/thread_info.h:150 [inline] > RIP: 0010:copy_from_user include/linux/uaccess.h:143 [inline] > RIP: 0010:drm_mode_createblob_ioctl+0x398/0x490 > drivers/gpu/drm/drm_property.c:800 > Code: c1 ea 03 80 3c 02 00 0f 85 ed 00 00 00 49 89 5d 00 e8 3c 28 cb fd 4c > 89 f7 e8 64 92 9e 03 31 c0 e9 75 fd ff ff e8 28 28 cb fd <0f> 0b e8 21 28 cb > fd 4d 85 e4 b8 f2 ff ff ff 0f 84 5b fd ff ff 89 > RSP: 0018:ffff8880584efaa8 EFLAGS: 00010246 > RAX: 0000000000040000 RBX: ffff8880a3a90000 RCX: ffffc900109da000 > RDX: 0000000000040000 RSI: ffffffff83a7eaf8 RDI: 0000000000000007 > RBP: ffff8880584efae8 R08: ffff888096c40080 R09: ffffed1014752110 > R10: ffffed101475210f R11: ffff8880a3a9087f R12: ffffc90014907000 > R13: ffff888028aa0000 R14: 000000009a6c7969 R15: ffffc90014907058 > > > --- > 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. -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
