From: Baoquan He Date: Fri, 29 Apr 2016 00:09:03 +0000 (-0700) Subject: x86/KASLR: Handle kernel relocations above 2G correctly X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6f9af75faa1df61e1ee5bea8a787a90605bb528d;p=linux-beck.git x86/KASLR: Handle kernel relocations above 2G correctly When processing the relocation table, the offset used to calculate the relocation is an 'int'. This is sufficient for calculating the physical address of the relocs entry on 32-bit systems and on 64-bit systems when the relocation is under 2G. To handle relocations above 2G (seen in situations like kexec, netboot, etc), this offset needs to be calculated using a 'long' to avoid wrapping and miscalculating the relocation. Signed-off-by: Baoquan He [ Rewrote the changelog. ] Signed-off-by: Kees Cook Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Young Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vivek Goyal Cc: Yinghai Lu Cc: lasse.collin@tukaani.org Link: http://lkml.kernel.org/r/1461888548-32439-2-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 6dde6ccdf00e..45145149c07d 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -232,7 +232,7 @@ static void handle_relocations(void *output, unsigned long output_len) * So we work backwards from the end of the decompressed image. */ for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) { - int extended = *reloc; + long extended = *reloc; extended += map; ptr = (unsigned long)extended;