diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c index 4f14b5ce6535..80254b47dc34 100644 --- a/arch/arm/kernel/module.c +++ b/arch/arm/kernel/module.c @@ -155,8 +155,17 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex, break; case R_ARM_PREL31: - offset = *(u32 *)loc + sym->st_value - loc; - *(u32 *)loc = offset & 0x7fffffff; + offset = (*(s32 *)loc << 1) >> 1; /* sign extend */ + offset += sym->st_value - loc; + if (offset >= 0x40000000 || offset < -0x40000000) { + pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n", + module->name, relindex, i, symname, + ELF32_R_TYPE(rel->r_info), loc, + sym->st_value); + return -ENOEXEC; + } + *(u32 *)loc &= 0x80000000; + *(u32 *)loc |= offset & 0x7fffffff; break; case R_ARM_MOVW_ABS_NC: