From: Paul Mackerras <paulus@samba.org>
Date: Sun, 1 May 2005 15:58:42 +0000 (-0700)
Subject: [PATCH] ppc32: Fix address checking on lmw/stmw align exception
X-Git-Tag: v2.6.12-rc4~136^2~162
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d5812a77e5803468a5033be91af978be0f7a17d9;p=linux-2.6

[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>
---

diff --git a/arch/ppc/kernel/align.c b/arch/ppc/kernel/align.c
index 40d356c66c..ff81da9598 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)