From: Peilin Ye <yepeilin.cs@gmail.com>
To: jslaby@suse.cz
Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-serial@vger.kernel.org, syzkaller-bugs@googlegroups.com,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: Re: [PATCH 15/16] vc_screen: extract vcs_read_buf_header
Date: Tue, 25 Aug 2020 12:48:04 -0400 [thread overview]
Message-ID: <20200825164804.860743-1-yepeilin.cs@gmail.com> (raw)
In-Reply-To: <20200818085706.12163-15-jslaby@suse.cz>
Hi all,
Link: https://syzkaller.appspot.com/bug?id=f332576321998d36cd07d09c9c1268cfed1895c9
As reported by syzbot, vcs_read_buf() is overflowing `con_buf16`, since
this patch removed the following check:
- if (count > CON_BUF_SIZE) {
- count = CON_BUF_SIZE;
- filled = count - pos;
- }
Decreasing `count` by `min(HEADER_SIZE - pos, count)` bypasses this check.
Additionally, this patch also removed updates to `skip` and `filled`.
What should we do in order to fix it?
Thank you,
Peilin Ye
WARNING: multiple messages have this Message-ID (diff)
From: Peilin Ye <yepeilin.cs@gmail.com>
To: jslaby@suse.cz
Cc: syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org,
linux-serial@vger.kernel.org,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: Re: [Linux-kernel-mentees] [PATCH 15/16] vc_screen: extract vcs_read_buf_header
Date: Tue, 25 Aug 2020 12:48:04 -0400 [thread overview]
Message-ID: <20200825164804.860743-1-yepeilin.cs@gmail.com> (raw)
In-Reply-To: <20200818085706.12163-15-jslaby@suse.cz>
Hi all,
Link: https://syzkaller.appspot.com/bug?id=f332576321998d36cd07d09c9c1268cfed1895c9
As reported by syzbot, vcs_read_buf() is overflowing `con_buf16`, since
this patch removed the following check:
- if (count > CON_BUF_SIZE) {
- count = CON_BUF_SIZE;
- filled = count - pos;
- }
Decreasing `count` by `min(HEADER_SIZE - pos, count)` bypasses this check.
Additionally, this patch also removed updates to `skip` and `filled`.
What should we do in order to fix it?
Thank you,
Peilin Ye
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next prev parent reply other threads:[~2020-08-25 16:49 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-18 8:56 [PATCH 01/16] vt: make vc_data pointers const in selection.h Jiri Slaby
2020-08-18 8:56 ` [PATCH 02/16] vt: declare xy for get/putconsxy properly Jiri Slaby
2020-08-18 11:43 ` Greg KH
2020-08-19 7:09 ` Jiri Slaby
2020-08-18 8:56 ` [PATCH 03/16] vc: propagate "viewed as bool" from screenpos up Jiri Slaby
2020-08-18 8:56 ` [PATCH 04/16] vc_screen: document and cleanup vcs_vc Jiri Slaby
2020-08-18 8:56 ` [PATCH 05/16] vc_screen: rewrite vcs_size to accept vc, not inode Jiri Slaby
2020-08-18 8:56 ` [PATCH 06/16] vc_screen: sanitize types in vcs_write Jiri Slaby
2020-08-18 8:56 ` [PATCH 07/16] vc_screen: extract vcs_write_buf_noattr Jiri Slaby
2020-08-18 8:56 ` [PATCH 08/16] vc_screen: extract vcs_write_buf Jiri Slaby
2020-08-18 8:56 ` [PATCH 09/16] vc_screen: eliminate ifdefs from vcs_write_buf Jiri Slaby
2020-08-18 8:57 ` [PATCH 10/16] vc_screen: sanitize types in vcs_read Jiri Slaby
2020-08-18 8:57 ` [PATCH 11/16] vs_screen: kill tmp_count from vcs_read Jiri Slaby
2020-08-18 8:57 ` [PATCH 12/16] vc_screen: extract vcs_read_buf_uni Jiri Slaby
2020-08-18 8:57 ` [PATCH 13/16] vc_screen: extract vcs_read_buf_noattr Jiri Slaby
2020-08-18 8:57 ` [PATCH 14/16] vc_screen: extract vcs_read_buf Jiri Slaby
2020-08-18 8:57 ` [PATCH 15/16] vc_screen: extract vcs_read_buf_header Jiri Slaby
2020-08-25 16:48 ` Peilin Ye [this message]
2020-08-25 16:48 ` [Linux-kernel-mentees] " Peilin Ye
2020-08-25 16:59 ` Greg KH
2020-08-25 16:59 ` [Linux-kernel-mentees] " Greg KH
2020-08-25 17:12 ` Peilin Ye
2020-08-25 17:12 ` [Linux-kernel-mentees] " Peilin Ye
2020-08-18 8:57 ` [PATCH 16/16] vc_screen: prune macros Jiri Slaby
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