[tip:core/rslib] rslib: decode_rs: Fix length parameter check

[tip-bot for Ferdinand Blomqvist]

Commit-ID:  a343536f8f482be6932803a023f46d0fa723ae56
Gitweb:     https://git.kernel.org/tip/a343536f8f482be6932803a023f46d0fa723ae56
Author:     Ferdinand Blomqvist <ferdinand.blomqvist@xxxxxxxxx>
AuthorDate: Thu, 20 Jun 2019 17:10:35 +0300
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 26 Jun 2019 14:55:46 +0200

rslib: decode_rs: Fix length parameter check

The length of the data load must be at least one. Or in other words,
there must be room for at least 1 data and nroots parity symbols after
shortening the RS code.

Signed-off-by: Ferdinand Blomqvist <ferdinand.blomqvist@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190620141039.9874-4-ferdinand.blomqvist@xxxxxxxxx

---
 lib/reed_solomon/decode_rs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/reed_solomon/decode_rs.c b/lib/reed_solomon/decode_rs.c
index 3313bf944ff1..22006eaa41e6 100644
--- a/lib/reed_solomon/decode_rs.c
+++ b/lib/reed_solomon/decode_rs.c
@@ -39,7 +39,7 @@
 
 	/* Check length parameter for validity */
 	pad = nn - nroots - len;
-	BUG_ON(pad < 0 || pad >= nn);
+	BUG_ON(pad < 0 || pad >= nn - nroots);
 
 	/* Does the caller provide the syndrome ? */
 	if (s != NULL)