glibc 2.15 and libasound

[Allin Cottrell <cottrell at wfu dot edu>]

There's a problem that quite a few people have noted with 
recent glibc and libasound (specifically the use of libdl by 
the latter). I was hoping this might have gone away with glibc 
2.15 but it's still there. Maybe it's not a glibc bug, though 
it looks rather like it. The symptom is that (e.g.) alsa's
"aplay" utility reliably segfaults when called to play a wav 
file.

I have inserted debugging statements in libasound (version 
1.0.25, dlmisc.c), to announce all its uses of the libdl 
functions, and run aplay under valgrind (where it doesn't 
actually segfault). I'm attaching the results. It looks as if 
there's something wrong with glibc's do_lookup_x(): it's 
reading from freed memory in response to dlsym() following a 
successful invocation of dlopen() by libasound.

--
Allin Cottrell
Department of Economics
Wake Forest University, NC

Attachment: valgrind.log
Description: Text document