Hi!
----
I did a test build with ast-ksh.2012-05-04 with $ (CCFLAGS='-g'
CC='gcc -std=gnu99 -D_AST_std_malloc=1 -DSHOPT_SYSRC -D_map_libc=1 -g'
./bin/package make) # (yes, yes CC/CCFLAGS abuse) to have a quick way
to let "valgrind" chew on ksh.
The first test of the resulting binary triggered a valgrind it for a
simple $ ksh -c 'cd /tmp' #:
-- snip --
$ valgrind ./arch/linux.i386-64/bin/ksh -c 'cd /tmp'
[snip]
==16737== Invalid read of size 1
==16737== at 0x4481CA: nv_putval (name.c:1852)
==16737== by 0x47CE0C: b_cd (cd_pwd.c:215)
==16737== by 0x468E0F: sh_exec (xec.c:1367)
==16737== by 0x408675: exfile (main.c:599)
==16737== by 0x407ACB: sh_main (main.c:373)
==16737== by 0x406E28: main (pmain.c:45)
==16737== Address 0x566ecf0 is 0 bytes inside a block of size 66 free'd
==16737== at 0x4C2892E: free (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==16737== by 0x50441B: _ast_free (malloc.c:1036)
==16737== by 0x47CDA3: b_cd (cd_pwd.c:210)
==16737== by 0x468E0F: sh_exec (xec.c:1367)
==16737== by 0x408675: exfile (main.c:599)
==16737== by 0x407ACB: sh_main (main.c:373)
==16737== by 0x406E28: main (pmain.c:45)
[snip]
-- snip --
Looking at the lines 209-215:
-- snip --
209 if(oldpwd)
210 free(oldpwd);
211 flag = strlen(dir);
212 /* delete trailing '/' */
213 while(--flag>0 && dir[flag]=='/')
214 dir[flag] = 0;
215 nv_putval(pwdnod,dir,NV_RDONLY);
-- snip --
It's early in the morning with ENOCOFFEE: Is it possible that there
are cases where |oldpwd| and |dir| are identical ?
AFAIK this patch should fix it (yes, yes, the |free()| could've been
placed after the |nv_putval(pwdnod,dir,NV_RDONLY)| but I've opted to
place it after all accesses to modify the shell variables):
-- snip --
--- src/cmd/ksh93/bltins/cd_pwd.c 2012-04-27 16:53:03.000000000 +0200
+++ src/cmd/ksh93/bltins/cd_pwd.c 2012-05-08 08:04:46.815518557 +0200
@@ -206,8 +206,6 @@
if(*dir != '/')
return(0);
nv_putval(opwdnod,oldpwd,NV_RDONLY);
- if(oldpwd)
- free(oldpwd);
flag = strlen(dir);
/* delete trailing '/' */
while(--flag>0 && dir[flag]=='/')
@@ -218,6 +216,8 @@
nv_scan(shp->track_tree,rehash,(void*)0,NV_TAGGED,NV_TAGGED);
path_newdir(shp,shp->pathlist);
path_newdir(shp,shp->cdpathlist);
+ if(oldpwd)
+ free(oldpwd);
return(0);
}
-- snip --
----
Bye,
Roland
--
__ . . __
(o.\ \/ /.o) [email protected]
\__\/\/__/ MPEG specialist, C&&JAVA&&Sun&&Unix programmer
/O /==\ O\ TEL +49 641 3992797
(;O/ \/ \O;)
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