If we manage to accidentally get a module installed that does not match
the system endianess (there is currently nothing preventing that in
OpenWrt/LEDE) we will hit a segmentation fault when doing this:
sh = (Elf32_Shdr *) (map + e->e_shoff);
because e->e_shoff will be wrongly encoded and this most likely will
result in an invalid offset to de-reference from.
Update elf_find_section() to check that the build time endianess of
kmodloader matches that of the module, otherwise nothing would work
really.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
static int elf_find_section(char *map, const char *section, unsigned int *offset, unsigned int *size)
{
int clazz = map[EI_CLASS];
+ int endian = map[EI_DATA];
+
+#if defined(__LITTLE_ENDIAN)
+ if (endian != ELFDATA2LSB)
+#elif defined(__BIG_ENDIAN)
+ if (endian != ELFDATA2MSB)
+#else
+#error "unsupported endian"
+#endif
+ {
+ ULOG_ERR("invalid endianess: %d\n", endian);
+ return -1;
+ }
if (clazz == ELFCLASS32)
return elf32_find_section(map, section, offset, size);