On Sat, Sep 26, 2020 at 9:19 AM syzbot <syzbot+a889d70ef11d6e0f6f22@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: 171d4ff7 Merge tag 'mmc-v5.9-rc4-2' of git://git.kernel.or.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=126e918d900000 > kernel config: https://syzkaller.appspot.com/x/.config?x=240e2ebab67245c7 > dashboard link: https://syzkaller.appspot.com/bug?extid=a889d70ef11d6e0f6f22 > compiler: gcc (GCC) 10.1.0-syz 20200507 > > Unfortunately, I don't have any reproducer for this issue yet. Looking at the backtrace, this could be fixed by the font size checks I just pushed: commit 5af08640795b2b9a940c9266c0260455377ae262 (HEAD -> drm-misc-fixes, drm-misc/for-linux-next-fixes, drm-misc/drm-misc-fixes) Author: Peilin Ye <yepeilin.cs@xxxxxxxxx> Date: Thu Sep 24 09:43:48 2020 -0400 fbcon: Fix global-out-of-bounds read in fbcon_get_font() But just an educated guess, no more. -Daniel > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+a889d70ef11d6e0f6f22@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KASAN: global-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:654 [inline] > BUG: KASAN: global-out-of-bounds in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] > BUG: KASAN: global-out-of-bounds in bit_putcs+0xbb6/0xd20 drivers/video/fbdev/core/bitblit.c:185 > Read of size 1 at addr ffffffff88db78e9 by task syz-executor.4/16465 > > CPU: 0 PID: 16465 Comm: syz-executor.4 Not tainted 5.9.0-rc6-syzkaller #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+0x198/0x1fd lib/dump_stack.c:118 > print_address_description.constprop.0.cold+0x5/0x497 mm/kasan/report.c:383 > __kasan_report mm/kasan/report.c:513 [inline] > kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 > __fb_pad_aligned_buffer include/linux/fb.h:654 [inline] > bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] > bit_putcs+0xbb6/0xd20 drivers/video/fbdev/core/bitblit.c:185 > fbcon_putcs+0x35a/0x450 drivers/video/fbdev/core/fbcon.c:1308 > do_update_region+0x399/0x630 drivers/tty/vt/vt.c:675 > redraw_screen+0x658/0x790 drivers/tty/vt/vt.c:1034 > fbcon_do_set_font+0x718/0x880 drivers/video/fbdev/core/fbcon.c:2438 > fbcon_copy_font+0x12f/0x1a0 drivers/video/fbdev/core/fbcon.c:2453 > con_font_copy drivers/tty/vt/vt.c:4719 [inline] > con_font_op+0x65b/0x1140 drivers/tty/vt/vt.c:4734 > vt_k_ioctl drivers/tty/vt/vt_ioctl.c:473 [inline] > vt_ioctl+0x21c9/0x2e90 drivers/tty/vt/vt_ioctl.c:852 > tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 > vfs_ioctl fs/ioctl.c:48 [inline] > __do_sys_ioctl fs/ioctl.c:753 [inline] > __se_sys_ioctl fs/ioctl.c:739 [inline] > __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x45e179 > Code: 3d b2 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 0b b2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fe2e03e5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 0000000000010840 RCX: 000000000045e179 > RDX: 0000000020000400 RSI: 0000000000004b72 RDI: 0000000000000003 > RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c > R13: 00007ffff7397e9f R14: 00007fe2e03e69c0 R15: 000000000118cf4c > > The buggy address belongs to the variable: > oid_index+0x109/0xae0 > > Memory state around the buggy address: > ffffffff88db7780: 00 00 00 00 01 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 > ffffffff88db7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06 f9 > >ffffffff88db7880: f9 f9 f9 f9 00 02 f9 f9 f9 f9 f9 f9 00 01 f9 f9 > ^ > ffffffff88db7900: f9 f9 f9 f9 00 04 f9 f9 f9 f9 f9 f9 00 00 02 f9 > ffffffff88db7980: f9 f9 f9 f9 00 03 f9 f9 f9 f9 f9 f9 07 f9 f9 f9 > ================================================================== > > > --- > 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. -- 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
