commit eda9cec4c9a12208a6f69fbe68f72a6311d50032
author Josh Poimboeuf <jpoimboe@redhat.com> Fri Nov 03 07:58:54 2017 -0500
committer Ingo Molnar <mingo@kernel.org> Sun Nov 05 09:52:16 2017 +0100
tree 36d9d40657db3ee47c3c38f9d255b6e763539628
parent 675357362aeba19688440eb1aaa7991067f73b12

x86/module: Detect and skip invalid relocations

There have been some cases where external tooling (e.g., kpatch-build)
creates a corrupt relocation which targets the wrong address.  This is a
silent failure which can corrupt memory in unexpected places.

On x86, the bytes of data being overwritten by relocations are always
initialized to zero beforehand.  Use that knowledge to add sanity checks
to detect such cases before they corrupt memory.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jeyu@kernel.org
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/37450d6c6225e54db107fba447ce9e56e5f758e9.1509713553.git.jpoimboe@redhat.com
[ Restructured the messages, as it's unclear whether the relocation or the target is corrupted. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>