drivers/message/i2o/i2o_config.c: bound allocation
Fix a case where users can try to allocate arbitarily large amounts of
memory. 64K is overkill for a config request so apply an upper bound.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/message/i2o/i2o_config.c b/drivers/message/i2o/i2o_config.c
index 098de2b..9a49c24 100644
--- a/drivers/message/i2o/i2o_config.c
+++ b/drivers/message/i2o/i2o_config.c
@@ -188,6 +188,13 @@
if (!dev)
return -ENXIO;
+ /*
+ * Stop users being able to try and allocate arbitary amounts
+ * of DMA space. 64K is way more than sufficient for this.
+ */
+ if (kcmd.oplen > 65536)
+ return -EMSGSIZE;
+
ops = memdup_user(kcmd.opbuf, kcmd.oplen);
if (IS_ERR(ops))
return PTR_ERR(ops);