[JFFS2] Check for all-zero node headers
Due to a poor choice of CRC32 seed, a node header which is all zeroes
would pass the CRC32 check. Explicitly check for this case, and treat it
as we do a CRC failure.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/fs/jffs2/scan.c b/fs/jffs2/scan.c
index 31c1475..7fb45bd4 100644
--- a/fs/jffs2/scan.c
+++ b/fs/jffs2/scan.c
@@ -734,6 +734,15 @@
ofs += 4;
continue;
}
+ /* Due to poor choice of crc32 seed, an all-zero node will have a correct CRC */
+ if (!je32_to_cpu(node->hdr_crc) && !je16_to_cpu(node->nodetype) &&
+ !je16_to_cpu(node->magic) && !je32_to_cpu(node->totlen)) {
+ noisy_printk(&noise, "jffs2_scan_eraseblock(): All zero node header at 0x%08x.\n", ofs);
+ if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
+ return err;
+ ofs += 4;
+ continue;
+ }
if (ofs + je32_to_cpu(node->totlen) >
jeb->offset + c->sector_size) {