In article 50BA09CC.2040104@flensrocker.de you write:
Am 30.11.2012 11:32, schrieb Gerald Dachs:
Am 2012-11-30 10:17, schrieb Lars Hanisch:
Looks like the pointer returned by sscanf is not valid:
32: bool tComponent::FromString(const char *s) 33: { 34: unsigned int Stream, Type; 35: int n = sscanf(s, "%X %02X %7s %a[^\n]", &Stream, &Type, language, &description); // 7 = MAXLANGCODE2 - 1 36: if (n != 4 || isempty(description)) { 37: free(description); 38: description = NULL; 39: } 40: stream = Stream; 41: type = Type; 42: return n >= 3; 43: }
From man sscanf:
The GNU C library supports a nonstandard extension that causes the library to dynamically allocate a string of sufficient size for input strings for the %s and %a[range] conversion specifiers.This is the reason why it doesn't work with ulibc.
Then there should be a malloc or something similiar for description:
32: bool tComponent::FromString(const char *s) 33: { 34: unsigned int Stream, Type; description = malloc(strlen(s)); description[0] = 0; 35: int n = sscanf(s, "%X %02X %7s %a[^\n]", &Stream, &Type, language, &description); // 7 = MAXLANGCODE2 - 1 36: if (n != 4 || isempty(description)) { 37: free(description); 38: description = NULL; 39: } 40: stream = Stream; 41: type = Type; 42: return n >= 3; 43: }
A check for description != NULL before the free call is not needed.
But this is not the only place in the vdr code, where %a is used...
Btw FreeBSD has the same problem (no *scanf %a in libc), so you could try taking the FreeBSD patches and replacing
#ifdef __FreeBSD__
by
#if defined(__FreeBSD__) || defined(__UCLIBC__)
in those parts handling %a here:
http://svnweb.freebsd.org/ports/head/multimedia/vdr/files/patch-vdr-1.7.28_F...
A few plugins are affected too: (of those we have in FreeBSD ports)
eepg:
http://svnweb.freebsd.org/ports/head/multimedia/vdr-plugin-eepg/files/patch-...
infosatepg:
http://svnweb.freebsd.org/ports/head/multimedia/vdr-plugin-infosatepg/files/...
ttxtsubs:
http://svnweb.freebsd.org/ports/head/multimedia/vdr-plugin-ttxtsubs/files/pa...
HTH, :) Juergen
PS: I think I never sent the FreeBSD patches to Klaus the last few times I updated them, atm FreeBSD ports is behind again (still at vdr 1.7.29), when I get around catching up to the latest version I can send the updated patches if you are interested, Klaus? A few more 1.7.29 patches are in here:
http://svnweb.freebsd.org/ports/head/multimedia/vdr/files/
(I think I did send FreeBSD patches to those plugin maintainers that may still be active some time ago, haven't heard back from many tho.)