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authorBaoquan He <bhe@redhat.com>2016-04-28 17:09:03 -0700
committerIngo Molnar <mingo@kernel.org>2016-04-29 09:58:26 +0200
commit6f9af75faa1df61e1ee5bea8a787a90605bb528d (patch)
tree4ea4640be2909a446adced25336557456b2d3729 /arch/x86/boot
parent81b785f3e4114ed74fceb48a54e7de2f797a2ba1 (diff)
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 <bhe@redhat.com> [ Rewrote the changelog. ] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> 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 <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/boot')
-rw-r--r--arch/x86/boot/compressed/misc.c2
1 files changed, 1 insertions, 1 deletions
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;