Messages in this thread | | | Date | Fri, 06 Jun 2014 13:53:02 -0400 | From | Sasha Levin <> | Subject | Re: net: llc: NULL ptr deref in llc_ui_sendmsg |
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On 06/06/2014 11:42 AM, Dave Jones wrote: > On Fri, Jun 06, 2014 at 11:08:33AM -0400, Sasha Levin wrote: > > Hi all, > > > > While fuzzing with trinity inside a KVM tools guest running the latest -next > > kernel I've stumbled on the following spew: > > > > [ 269.531162] BUG: unable to handle kernel NULL pointer dereference at 000000000000021e > > [ 269.531217] IP: llc_ui_sendmsg (net/llc/af_llc.c:912) > > 905 /* must bind connection to sap if user hasn't done it. */ > 906 if (sock_flag(sk, SOCK_ZAPPED)) { > 907 /* bind to sap with null dev, exclusive. */ > 908 rc = llc_ui_autobind(sock, addr); > 909 if (rc) > 910 goto release; > 911 } > 912 hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr); > > looks like llc->dev was null, (understandable, given Trinity doesn't really know > how to set up llc beyond random socket()/setsockopt() calls). > > llc_ui_autobind returns -ENODEV in that case, so it looks like the SOCK_ZAPPED test > was false. Something like the patch below maybe ? It feels ugly to be duplicating that > test there, but if this is agreed upon I'll resubmit this properly.
I figured it's something more complicated than that since trinity stumbled on it only now and I don't see any code changes in that area. I'll test it with the patch.
Thanks, Sasha
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