From fca5c84720a2171a32b81f6afa7840ab6a8ab7d2 Mon Sep 17 00:00:00 2001
From: Behan Webster <behanw@converseincode.com>
Date: Thu, 8 Nov 2012 11:24:46 -0500
Subject: [PATCH] --- yaml --- r: 344842 b: refs/heads/master c:
 fd47d3e1c2949838e858379aaf2bc20647be2912 h: refs/heads/master v: v3

---
 [refs]                     | 2 +-
 trunk/include/linux/jbd2.h | 8 +++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 6658f68081cf..71538f957b84 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 37be2f59d3149b95afaeeeff94edde2c07f165d2
+refs/heads/master: fd47d3e1c2949838e858379aaf2bc20647be2912
diff --git a/trunk/include/linux/jbd2.h b/trunk/include/linux/jbd2.h
index de7f55682088..1be23d9fdacb 100644
--- a/trunk/include/linux/jbd2.h
+++ b/trunk/include/linux/jbd2.h
@@ -1302,15 +1302,21 @@ static inline int jbd_space_needed(journal_t *journal)
 
 extern int jbd_blocks_per_page(struct inode *inode);
 
+/* JBD uses a CRC32 checksum */
+#define JBD_MAX_CHECKSUM_SIZE 4
+
 static inline u32 jbd2_chksum(journal_t *journal, u32 crc,
 			      const void *address, unsigned int length)
 {
 	struct {
 		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(journal->j_chksum_driver)];
+		char ctx[JBD_MAX_CHECKSUM_SIZE];
 	} desc;
 	int err;
 
+	BUG_ON(crypto_shash_descsize(journal->j_chksum_driver) >
+		JBD_MAX_CHECKSUM_SIZE);
+
 	desc.shash.tfm = journal->j_chksum_driver;
 	desc.shash.flags = 0;
 	*(u32 *)desc.ctx = crc;