diff --git a/debian/changelog b/debian/changelog
index 581b500..04260f2 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+genext2fs (1.4.1-4) UNRELEASED; urgency=low
+
+  * debian/patches/byteswap_fix.diff: New patch by Samuel Thibault,
+    fix a segfault in the byte swapping code on little-endian architectures
+    (closes: 644776).
+
+ -- Jérémie Koenig <jk@jk.fr.eu.org>  Tue, 29 Nov 2011 17:18:12 +0100
+
 genext2fs (1.4.1-3) unstable; urgency=low
 
   * New maintainer (closes: 579369).
diff --git a/debian/patches/byteswap_fix.diff b/debian/patches/byteswap_fix.diff
new file mode 100644
index 0000000..7b3c00b
--- /dev/null
+++ b/debian/patches/byteswap_fix.diff
@@ -0,0 +1,44 @@
+Index: genext2fs/genext2fs.c
+===================================================================
+--- genext2fs.orig/genext2fs.c	2011-11-29 17:36:06.000000000 +0100
++++ genext2fs/genext2fs.c	2011-11-29 17:37:37.000000000 +0100
+@@ -1779,7 +1779,8 @@
+ 	assert(nod->i_block[EXT2_DIND_BLOCK] != 0);
+ 	for(i = 0; i < BLOCKSIZE/4; i++)
+ 		if(nblk > EXT2_IND_BLOCK + BLOCKSIZE/4 + (BLOCKSIZE/4)*i )
+-			swap_block(get_blk(fs, ((uint32*)get_blk(fs, nod->i_block[EXT2_DIND_BLOCK]))[i]));
++			if (((uint32*)get_blk(fs, nod->i_block[EXT2_DIND_BLOCK]))[i])
++				swap_block(get_blk(fs, ((uint32*)get_blk(fs, nod->i_block[EXT2_DIND_BLOCK]))[i]));
+ 	swap_block(get_blk(fs, nod->i_block[EXT2_DIND_BLOCK]));
+ 	if(nblk <= EXT2_IND_BLOCK + BLOCKSIZE/4 + BLOCKSIZE/4 * BLOCKSIZE/4)
+ 		return;
+@@ -1792,7 +1793,8 @@
+ 				     (BLOCKSIZE/4)*(BLOCKSIZE/4) + 
+ 				     i*(BLOCKSIZE/4)*(BLOCKSIZE/4) + 
+ 				     j*(BLOCKSIZE/4)) ) 
+-			  swap_block(get_blk(fs,b2[j]));
++			  if (b2[j])
++			  	swap_block(get_blk(fs,b2[j]));
+ 			else {
+ 			  done = 1;
+ 			  break;
+@@ -1825,7 +1827,8 @@
+ 	swap_block(get_blk(fs, nod->i_block[EXT2_DIND_BLOCK]));
+ 	for(i = 0; i < BLOCKSIZE/4; i++)
+ 		if(nblk > EXT2_IND_BLOCK + BLOCKSIZE/4 + (BLOCKSIZE/4)*i )
+-			swap_block(get_blk(fs, ((uint32*)get_blk(fs, nod->i_block[EXT2_DIND_BLOCK]))[i]));
++			if (((uint32*)get_blk(fs, nod->i_block[EXT2_DIND_BLOCK]))[i])
++				swap_block(get_blk(fs, ((uint32*)get_blk(fs, nod->i_block[EXT2_DIND_BLOCK]))[i]));
+ 	if(nblk <= EXT2_IND_BLOCK + BLOCKSIZE/4 + BLOCKSIZE/4 * BLOCKSIZE/4)
+ 		return;
+ 	/* Adding support for triple indirection */
+@@ -1839,7 +1842,8 @@
+ 				     (BLOCKSIZE/4)*(BLOCKSIZE/4) + 
+ 				     i*(BLOCKSIZE/4)*(BLOCKSIZE/4) + 
+ 				     j*(BLOCKSIZE/4)) ) 
+-			  swap_block(get_blk(fs,b2[j]));
++			  if (b2[j])
++				swap_block(get_blk(fs,b2[j]));
+ 			else {
+ 			  done = 1;
+ 			  break;
diff --git a/debian/patches/series b/debian/patches/series
index 4dd8d0a..2883ba0 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -1,3 +1,4 @@
 c99_scanf.diff
 autoconf.diff
 blocksize+creator.diff
+byteswap_fix.diff