ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE

The arm compiler internally interprets an inline assembly label
as an unsigned long value, not a pointer. As a result, under
CONFIG_FORTIFY_SOURCE, the address of a label has a size of 4 bytes,
which was tripping the runtime checks. Instead, we can just cast the label
(as done with the size calculations earlier).

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1639397

Reported-by: William Cohen <wcohen@redhat.com>
Fixes: 6974f0c455 ("include/linux/string.h: add the option of fortified string.h functions")
Cc: stable@vger.kernel.org
Acked-by: Laura Abbott <labbott@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: William Cohen <wcohen@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Kees Cook 2018-10-30 22:12:56 +01:00 committed by Russell King
parent 651022382c
commit e46daee53b

View File

@ -247,7 +247,7 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *or
} }
/* Copy arch-dep-instance from template. */ /* Copy arch-dep-instance from template. */
memcpy(code, &optprobe_template_entry, memcpy(code, (unsigned char *)optprobe_template_entry,
TMPL_END_IDX * sizeof(kprobe_opcode_t)); TMPL_END_IDX * sizeof(kprobe_opcode_t));
/* Adjust buffer according to instruction. */ /* Adjust buffer according to instruction. */