lib/scatterlist: error handling in __sg_alloc_table()
I was reviewing code which I suspected might allocate a zero size SG
table. That will cause memory corruption. Also we can't return before
doing the memset or we could end up using uninitialized memory in the
cleanup path.
Signed-off-by: Dan Carpenter <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Imre Deak <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Maxim Levitsky <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index 129a82f..a685c8a 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -247,13 +247,15 @@
struct scatterlist *sg, *prv;
unsigned int left;
+ memset(table, 0, sizeof(*table));
+
+ if (nents == 0)
+ return -EINVAL;
#ifndef ARCH_HAS_SG_CHAIN
if (WARN_ON_ONCE(nents > max_ents))
return -EINVAL;
#endif
- memset(table, 0, sizeof(*table));
-
left = nents;
prv = NULL;
do {
