IB/uverbs: Check input length in flow steering uverbs
Since ib_copy_from_udata() doesn't check yet the available input data
length before accessing userspace memory, an explicit check of this
length is required to prevent:
- reading past the user provided buffer,
- underflow when subtracting the expected command size from the input
length.
This will ensure the newly added flow steering uverbs don't try to
process truncated commands.
Link: http://marc.info/?i=cover.1386798254.git.ydroneaud@opteya.com>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 45fb80b..f1cc838 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -2649,6 +2649,9 @@
void *ib_spec;
int i;
+ if (ucore->inlen < sizeof(cmd))
+ return -EINVAL;
+
if (ucore->outlen < sizeof(resp))
return -ENOSPC;
@@ -2799,6 +2802,9 @@
struct ib_uobject *uobj;
int ret;
+ if (ucore->inlen < sizeof(cmd))
+ return -EINVAL;
+
ret = ib_copy_from_udata(&cmd, ucore, sizeof(cmd));
if (ret)
return ret;