[JFFS2] Check for creation of dirents with embedded zero bytes in name.

I have no idea how this happened, but OLPC trac #4184 suggests that it
did. Catch it early.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

diff --git a/fs/jffs2/write.c b/fs/jffs2/write.c
index 664c164aa67c19bef7583ce6fa7014cc715ffef5..2f5695446d0f56eb92d0e2b8f26e90a7ed2938c3 100644 (file)
--- a/fs/jffs2/write.c
+++ b/fs/jffs2/write.c
@@ -215,6 +215,17 @@ struct jffs2_full_dirent *jffs2_write_dirent(struct jffs2_sb_info *c, struct jff
                BUG();
           });
 
+       if (strnlen(name, namelen) != namelen) {
+               /* This should never happen, but seems to have done on at least one
+                  occasion: https://dev.laptop.org/ticket/4184 */
+               printk(KERN_CRIT "Error in jffs2_write_dirent() -- name contains zero bytes!\n");
+               printk(KERN_CRIT "Directory inode #%u, name at *0x%p \"%s\"->ino #%u, name_crc 0x%08x\n",
+                      je32_to_cpu(rd->pino), name, name, je32_to_cpu(rd->ino),
+                      je32_to_cpu(rd->name_crc));
+               WARN_ON(1);
+               return ERR_PTR(-EIO);
+       }
+
        vecs[0].iov_base = rd;
        vecs[0].iov_len = sizeof(*rd);
        vecs[1].iov_base = (unsigned char *)name;
@@ -226,7 +237,7 @@ struct jffs2_full_dirent *jffs2_write_dirent(struct jffs2_sb_info *c, struct jff
 
        fd->version = je32_to_cpu(rd->version);
        fd->ino = je32_to_cpu(rd->ino);
-       fd->nhash = full_name_hash(name, strlen(name));
+       fd->nhash = full_name_hash(name, namelen);
        fd->type = rd->type;
        memcpy(fd->name, name, namelen);
        fd->name[namelen]=0;