Re: [Qemu-devel] possible denial of service via VNC

2014-06-30 Thread Gerd Hoffmann
On So, 2014-06-29 at 14:16 +0200, Peter Lieven wrote: Hi, while debugging a VNC issue I found this: case VNC_MSG_CLIENT_CUT_TEXT: if (len == 1) return 8; if (len == 8) { uint32_t dlen = read_u32(data, 4); if (dlen 0)

Re: [Qemu-devel] possible denial of service via VNC

2014-06-30 Thread Peter Lieven
On 30.06.2014 09:33, Gerd Hoffmann wrote: On So, 2014-06-29 at 14:16 +0200, Peter Lieven wrote: Hi, while debugging a VNC issue I found this: case VNC_MSG_CLIENT_CUT_TEXT: if (len == 1) return 8; if (len == 8) { uint32_t dlen = read_u32(data,

Re: [Qemu-devel] possible denial of service via VNC

2014-06-30 Thread Gerd Hoffmann
Hi, I would vote for disconnect as soon as the limit specified is too big. Otherwise we had to rewrite the whole receive logic which could introduce additional bugs. Sounds sensible. cheers, Gerd

Re: [Qemu-devel] possible denial of service via VNC

2014-06-30 Thread Peter Lieven
On 30.06.2014 09:46, Gerd Hoffmann wrote: Hi, I would vote for disconnect as soon as the limit specified is too big. Otherwise we had to rewrite the whole receive logic which could introduce additional bugs. Sounds sensible. Especially since client_cut_text is currently a NOP. Peter

[Qemu-devel] possible denial of service via VNC

2014-06-29 Thread Peter Lieven
Hi, while debugging a VNC issue I found this: case VNC_MSG_CLIENT_CUT_TEXT: if (len == 1) return 8; if (len == 8) { uint32_t dlen = read_u32(data, 4); if (dlen 0) return 8 + dlen; } client_cut_text(vs,

Re: [Qemu-devel] possible denial of service via VNC

2014-06-29 Thread Anthony Liguori
On Sun, Jun 29, 2014 at 5:16 AM, Peter Lieven p...@kamp.de wrote: Hi, while debugging a VNC issue I found this: case VNC_MSG_CLIENT_CUT_TEXT: if (len == 1) return 8; if (len == 8) { uint32_t dlen = read_u32(data, 4); if (dlen 0)