From: "zhangxiaoxu (A)" <zhangxiaoxu5@huawei.com> To: "Ville Syrjälä" <ville.syrjala@linux.intel.com> Cc: akpm@osdl.org, pmladek@suse.com, wangkefeng.wang@huawei.com, b.zolnierkie@samsung.com, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, sergey.senozhatsky@gmail.com Subject: Re: [PATCH] vgacon: Fix a UAF in vgacon_invert_region Date: Wed, 04 Mar 2020 01:31:20 +0000 [thread overview] Message-ID: <5c63d51f-b396-f2a7-a7c2-3b8af0bb54b0@huawei.com> (raw) In-Reply-To: <20200303144649.GT13686@intel.com> 在 2020/3/3 22:46, Ville Syrjälä 写道: > On Tue, Mar 03, 2020 at 10:30:14PM +0800, zhangxiaoxu (A) wrote: >> >> >> 在 2020/3/3 21:59, Ville Syrjälä 写道: >>> That doesn't match how vc_screenbuf_size is computed elsewhere. Also >>> a lot of places seem to assume that the screenbuf can be larger than >>> vga_vram_size (eg. all the memcpy()s pick the smaller size of the >>> two). >> Yes, in the vga source code, we also pick the smaller size of two. But >> in other place, eg: vc_do_resize, copy the old_origin to new_origin, we >> not do that. It also make bad access happen. it maybe CVE-2020-8647. >> >> I think we should just assume the width/height maybe larger than the >> default, not the screenbuf larger than vga_vram_size. >> >> If not, any useful of the larger screenbuf? > > Maybe used for scrolling? The screenbuf just allocated with cols and rows, it can be save just one screen? vc_do_resize is the largest size which one screen can be shown? If so, we can't set the screen to the resolution which more than it's capability? > >> >>> >>> And you're changing the behaviour of the code when >>> 'width % 2 && user' is true >
WARNING: multiple messages have this Message-ID (diff)
From: "zhangxiaoxu (A)" <zhangxiaoxu5@huawei.com> To: "Ville Syrjälä" <ville.syrjala@linux.intel.com> Cc: akpm@osdl.org, pmladek@suse.com, wangkefeng.wang@huawei.com, b.zolnierkie@samsung.com, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, sergey.senozhatsky@gmail.com Subject: Re: [PATCH] vgacon: Fix a UAF in vgacon_invert_region Date: Wed, 4 Mar 2020 09:31:20 +0800 [thread overview] Message-ID: <5c63d51f-b396-f2a7-a7c2-3b8af0bb54b0@huawei.com> (raw) In-Reply-To: <20200303144649.GT13686@intel.com> 在 2020/3/3 22:46, Ville Syrjälä 写道: > On Tue, Mar 03, 2020 at 10:30:14PM +0800, zhangxiaoxu (A) wrote: >> >> >> 在 2020/3/3 21:59, Ville Syrjälä 写道: >>> That doesn't match how vc_screenbuf_size is computed elsewhere. Also >>> a lot of places seem to assume that the screenbuf can be larger than >>> vga_vram_size (eg. all the memcpy()s pick the smaller size of the >>> two). >> Yes, in the vga source code, we also pick the smaller size of two. But >> in other place, eg: vc_do_resize, copy the old_origin to new_origin, we >> not do that. It also make bad access happen. it maybe CVE-2020-8647. >> >> I think we should just assume the width/height maybe larger than the >> default, not the screenbuf larger than vga_vram_size. >> >> If not, any useful of the larger screenbuf? > > Maybe used for scrolling? The screenbuf just allocated with cols and rows, it can be save just one screen? vc_do_resize is the largest size which one screen can be shown? If so, we can't set the screen to the resolution which more than it's capability? > >> >>> >>> And you're changing the behaviour of the code when >>> 'width % 2 && user' is true > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2020-03-04 1:31 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-03 3:20 [PATCH] vgacon: Fix a UAF in vgacon_invert_region Zhang Xiaoxu 2020-03-03 3:20 ` Zhang Xiaoxu 2020-03-03 13:59 ` Ville Syrjälä 2020-03-03 13:59 ` Ville Syrjälä 2020-03-03 14:30 ` zhangxiaoxu (A) 2020-03-03 14:30 ` zhangxiaoxu (A) 2020-03-03 14:46 ` Ville Syrjälä 2020-03-03 14:46 ` Ville Syrjälä 2020-03-04 1:31 ` zhangxiaoxu (A) [this message] 2020-03-04 1:31 ` zhangxiaoxu (A)
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=5c63d51f-b396-f2a7-a7c2-3b8af0bb54b0@huawei.com \ --to=zhangxiaoxu5@huawei.com \ --cc=akpm@osdl.org \ --cc=b.zolnierkie@samsung.com \ --cc=dri-devel@lists.freedesktop.org \ --cc=linux-fbdev@vger.kernel.org \ --cc=pmladek@suse.com \ --cc=sergey.senozhatsky@gmail.com \ --cc=ville.syrjala@linux.intel.com \ --cc=wangkefeng.wang@huawei.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: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.