[Asterisk-Dev] The '%' char and vs[n]printf at logger.c

[Michael Manousos]

I'm getting spurious crashes of Asterisk (stable) all with the following
backtrace:

#0  0xb7e1550d in vfprintf () from /lib/libc.so.6
#1  0xb7e11cf3 in vfprintf () from /lib/libc.so.6
#2  0xb7e3064c in vsnprintf () from /lib/libc.so.6
#3  0x08053e03 in ast_log (level=5, file=0x80cd439 "logger.c", line=645, 
function=0x80cd4e8 "ast_verbose",
     fmt=0x80eeaa0 "    -- Executing GotoIf(\"SIP/xxxxxxxx\", 
\"0?unauthenticated|%232107788861|1\") in new stack\n") at logger.c:562
#4  0x0805406e in ast_verbose (fmt=0x80d5be0 "    -- Executing 
%s(\"%s\", \"%s\") %s\n") at logger.c:645
#5  0x0807d3a4 in pbx_extension_helper (c=0xb50a4d78, context=0xb50a4ed0 
"XXXXXXXX", exten=0xb50a4fc4 "%232107788861", priority=2,
     callerid=0xb50a4fc4 "%232107788861", action=-1107306556) at utils.h:20
#6  0x080773ab in ast_pbx_run (c=0xb50a4d78) at pbx.c:1757
#7  0x0807da81 in pbx_thread (data=0xbdff6710) at pbx.c:1980
#8  0xb7f9adfe in pthread_start_thread () from /lib/libpthread.so.0
#9  0xb7e899aa in clone () from /lib/libc.so.6

The backtrace looked too weird until I noticed that there is a '%' char
at the format argument, passed to vsnprintf, without the intension to
act as a conversion specifier (it is just the number called by a SIP
user). I'm not able to duplicate the crash on a different box but it
seems as a bug to me.

More ideas?

Michael.