Re: [Bugme-new] [Bug 8726] New: MSG_TRUNC not regarded in unix_dgram_recvmsg()

On Mon,  9 Jul 2007 04:01:58 -0700 (PDT) bugme-daemon@bugzilla.kernel.org wrote:

http://bugzilla.kernel.org/show_bug.cgi?id=8726

           Summary: MSG_TRUNC not regarded in unix_dgram_recvmsg()
           Product: Networking
           Version: 2.5
     KernelVersion: 2.6.19
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Other
        AssignedTo: acme@ghostprotocols.net
        ReportedBy: garkein@mailueberfall.de


Problem Description:

In unix_dgram_recvmsg() in af_unix.c the flag MSG_TRUNC is not regarded as
described in the recv(2) man page.

This did work in older kernels (I have a working 2.6.13, but am not sure if
that is a plain kernel.org one, nor if it was the last working revision).
I believe the bug was introduced when the variable "copied" was removed from
the code.

IMHO, the line 1650:

err = size;

should read

err = (flags & MSG_TRUNC) ? skb->len : size;