From: syzbot <syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com>
To: b.zolnierkie@samsung.com, daniel.vetter@ffwll.ch,
dri-devel@lists.freedesktop.org, george.kennedy@oracle.com,
gregkh@linuxfoundation.org, jirislaby@kernel.org,
linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org,
natechancellor@gmail.com, sam@ravnborg.org,
syzkaller-bugs@googlegroups.com, yepeilin.cs@gmail.com
Subject: Re: BUG: unable to handle kernel NULL pointer dereference in fbcon_cursor
Date: Sun, 17 Jan 2021 00:53:23 -0800 [thread overview]
Message-ID: <000000000000e325f205b914bc4c@google.com> (raw)
In-Reply-To: <00000000000091111005b435456e@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: b3a3cbde Add linux-next specific files for 20210115
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=164096d7500000
kernel config: https://syzkaller.appspot.com/x/.config?x=6ea08dae6aab586f
dashboard link: https://syzkaller.appspot.com/bug?extid=b67aaae8d3a927f68d20
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15cd8fe0d00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17af5258d00000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 12267067 P4D 12267067 PUD 11841067 PMD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8463 Comm: syz-executor088 Not tainted 5.11.0-rc3-next-20210115-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000132f850 EFLAGS: 00010292
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000000007
RDX: 0000000000000002 RSI: ffff88814394b000 RDI: ffff888010071000
RBP: ffff888010071000 R08: 0000000000000000 R09: ffffffff83ed87ea
R10: 0000000000000003 R11: 0000000000000018 R12: ffff88814394b000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000720
FS: 0000000000db8880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000020cd8000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
fbcon_cursor+0x50e/0x620 drivers/video/fbdev/core/fbcon.c:1336
hide_cursor+0x85/0x280 drivers/tty/vt/vt.c:907
redraw_screen+0x5b4/0x740 drivers/tty/vt/vt.c:1012
vc_do_resize+0xed8/0x1150 drivers/tty/vt/vt.c:1325
fbcon_set_disp+0x7a8/0xe10 drivers/video/fbdev/core/fbcon.c:1402
con2fb_init_display drivers/video/fbdev/core/fbcon.c:808 [inline]
set_con2fb_map+0x7a6/0xf80 drivers/video/fbdev/core/fbcon.c:879
fbcon_set_con2fb_map_ioctl+0x165/0x220 drivers/video/fbdev/core/fbcon.c:3010
do_fb_ioctl+0x5b6/0x690 drivers/video/fbdev/core/fbmem.c:1156
fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1185
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: 0033:0x4402b9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffffae24f88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004402b9
RDX: 0000000020000080 RSI: 0000000000004610 RDI: 0000000000000004
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000401ac0
R13: 0000000000401b50 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: 0000000000000000
---[ end trace 5adb9f198fe5efa6 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000132f850 EFLAGS: 00010292
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000000007
RDX: 0000000000000002 RSI: ffff88814394b000 RDI: ffff888010071000
RBP: ffff888010071000 R08: 0000000000000000 R09: ffffffff83ed87ea
R10: 0000000000000003 R11: 0000000000000018 R12: ffff88814394b000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000720
FS: 0000000000db8880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000020cd8000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
next prev parent reply other threads:[~2021-01-17 8:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-16 8:36 BUG: unable to handle kernel NULL pointer dereference in fbcon_cursor syzbot
2021-01-17 8:53 ` syzbot [this message]
2021-01-17 11:29 ` syzbot
2021-01-18 9:29 ` Daniel Vetter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=000000000000e325f205b914bc4c@google.com \
--to=syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com \
--cc=b.zolnierkie@samsung.com \
--cc=daniel.vetter@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=george.kennedy@oracle.com \
--cc=gregkh@linuxfoundation.org \
--cc=jirislaby@kernel.org \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=natechancellor@gmail.com \
--cc=sam@ravnborg.org \
--cc=syzkaller-bugs@googlegroups.com \
--cc=yepeilin.cs@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox