pstore/ram: Add kmsg hlen zero check to ramoops_pstore_write()

If zero-length header happened in ramoops_write_kmsg_hdr(), that means we will not be able to read back dmesg record later, since it will be treated as invalid header in ramoops_pstore_read(). So we should not execute the following code but return the error. Signed-off-by: Yue Hu <[email protected]> Signed-off-by: Kees Cook <[email protected]>
ambv · Feb 12, 2019 · 47afd7a · 47afd7a
1 parent 1e0f67a
commit 47afd7a
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
@@ -425,6 +425,9 @@ static int notrace ramoops_pstore_write(struct pstore_record *record)
 
 	/* Build header and append record contents. */
 	hlen = ramoops_write_kmsg_hdr(prz, record);
+	if (!hlen)
+		return -ENOMEM;
+
 	size = record->size;
 	if (size + hlen > prz->buffer_size)
 		size = prz->buffer_size - hlen;