lib/lzo/lzo1x_compress.c: fix alignment bug in lzo-rle

commit 09b35b4192f6682dff96a093ab1930998cdb73b4 upstream.

Fix an unaligned access which breaks on platforms where this is not
permitted (e.g., Sparc).

Link: http://lkml.kernel.org/r/20190912145502.35229-1-dave.rodgman@arm.com
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
Cc: Dave Rodgman <dave.rodgman@arm.com>
Cc: Markus F.X.J. Oberhumer <markus@oberhumer.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/lib/lzo/lzo1x_compress.c b/lib/lzo/lzo1x_compress.c
index ba16c08e8cb921c618dd876e5c8166f101ac6396..717c940112f9d71ecb1fab13008a2d2cdb31522c 100644 (file)
--- a/lib/lzo/lzo1x_compress.c
+++ b/lib/lzo/lzo1x_compress.c
@@ -83,17 +83,19 @@ next:
                                        ALIGN((uintptr_t)ir, 4)) &&
                                        (ir < limit) && (*ir == 0))
                                ir++;
-                       for (; (ir + 4) <= limit; ir += 4) {
-                               dv = *((u32 *)ir);
-                               if (dv) {
+                       if (IS_ALIGNED((uintptr_t)ir, 4)) {
+                               for (; (ir + 4) <= limit; ir += 4) {
+                                       dv = *((u32 *)ir);
+                                       if (dv) {
 #  if defined(__LITTLE_ENDIAN)
-                                       ir += __builtin_ctz(dv) >> 3;
+                                               ir += __builtin_ctz(dv) >> 3;
 #  elif defined(__BIG_ENDIAN)
-                                       ir += __builtin_clz(dv) >> 3;
+                                               ir += __builtin_clz(dv) >> 3;
 #  else
 #    error "missing endian definition"
 #  endif
-                                       break;
+                                               break;
+                                       }
                                }
                        }
 #endif