From c6053034e996453cf204fc55f05fd04d6a66755a Mon Sep 17 00:00:00 2001 From: Roman Lebedev Date: Sat, 13 Jun 2015 16:50:55 +0300 Subject: [PATCH] babl_type_new(): fix global-buffer-overflow If we pass a string into this function, and this string is shorter than sizeof(Babl), macro BABL_IS_BABL() will read past string bounds, and bad things may happen. NOTE: if a string will be passed into this function, that is not handled by those if (!strcmp (arg, "<...>")), global-buffer-overflow will still happen. i am not sure if/what can be done about it :( Fixes following error: ================================================================= ==25849==ERROR: AddressSanitizer: global-buffer-overflow on address 0x7f7faec97940 at pc 0x7f7faec8b9bc bp 0x7ffd22ab9210 sp 0x7ffd22ab9208 READ of size 4 at 0x7f7faec97940 thread T0 0 0x7f7faec8b9bb in babl_type_new /home/lebedevri/src/_GIMP/babl/babl/babl-type.c:88 1 0x7f7faec74ba9 in babl_core_init /home/lebedevri/src/_GIMP/babl/babl/babl-core.c:90 2 0x7f7faec71379 in babl_init /home/lebedevri/src/_GIMP/babl/babl/babl.c:145 3 0x7f7fb342a3d1 in gegl_post_parse_hook (/usr/local/lib/libgegl-0.3.so.0+0x523d1) 4 0x7f7fae525238 in g_option_context_parse (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x55238) 5 0x7f7fae526193 in g_option_context_parse_strv (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x56193) 6 0x48b8cf in main (/usr/local/bin/gimp-2.9+0x48b8cf) 7 0x7f7fad539b44 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b44) 8 0x486b68 (/usr/local/bin/gimp-2.9+0x486b68) 0x7f7faec97943 is located 0 bytes to the right of global variable '*.LC1' from 'babl-core.c' (0x7f7faec97940) of size 3 '*.LC1' is ascii string 'id' SUMMARY: AddressSanitizer: global-buffer-overflow /home/lebedevri/src/_GIMP/babl/babl/babl-type.c:88 babl_type_new Shadow bytes around the buggy address: 0x0ff075d8af10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>0x0ff075d8af20: 05 f9 f9 f9 f9 f9 f9 f9[03]f9 f9 f9 f9 f9 f9 f9 0x0ff075d8af30: 07 f9 f9 f9 f9 f9 f9 f9 07 f9 f9 f9 f9 f9 f9 f9 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Heap right redzone: fb Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack partial redzone: f4 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Contiguous container OOB:fc ASan internal: fe ==25849==ABORTING --- babl/babl-type.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/babl/babl-type.c b/babl/babl-type.c index a6723f5..f99c9d1 100644 --- a/babl/babl-type.c +++ b/babl/babl-type.c @@ -85,15 +85,7 @@ babl_type_new (void *first_arg, if (!arg) break; - if (BABL_IS_BABL (arg)) - { -#ifdef BABL_LOG - Babl *babl = (Babl *) arg; - - babl_log ("%s unexpected", babl_class_name (babl->class_type)); -#endif - } - /* if we didn't point to a babl, we assume arguments to be strings */ + /* first, we assume arguments to be strings */ else if (!strcmp (arg, "id")) { id = va_arg (varg, int); @@ -124,6 +116,15 @@ babl_type_new (void *first_arg, (void) va_arg (varg, double); } + /* if we didn't point to a known string, we assume argument to be babl */ + else if (BABL_IS_BABL (arg)) + { +#ifdef BABL_LOG + Babl *babl = (Babl *) arg; + + babl_log ("%s unexpected", babl_class_name (babl->class_type)); +#endif + } else { babl_fatal ("unhandled argument '%s' for format '%s'", arg, name); -- 2.30.2