[PATCH] ppc32: Fix address checking on lmw/stmw align exception

The handling of misaligned load/store multiple instructions did not check
to see if the address was ok to access before using __{get,put}_user().

Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/ppc/kernel/align.c b/arch/ppc/kernel/align.c
index 40d356c66c41..ff81da9598d8 100644
--- a/arch/ppc/kernel/align.c
+++ b/arch/ppc/kernel/align.c
@@ -290,6 +290,10 @@ fix_alignment(struct pt_regs *regs)
                         /* lwm, stmw */
                         nb = (32 - reg) * 4;
                 }
+
+                if (!access_ok((flags & ST? VERIFY_WRITE: VERIFY_READ), addr, nb+nb0))
+                        return -EFAULT; /* bad address */
+
                 rptr = (unsigned char *) &regs->gpr[reg];
                 if (flags & LD) {
                         for (i = 0; i < nb; ++i)