In the expression "cmd.wqe_size * cmd.wr_count", both variables are u32
values that come from the user so the multiplication can lead to integer
wrapping. Then we pass the result to uverbs_request_next_ptr() which also
could potentially wrap. The "cmd.sge_count * sizeof(struct ib_uverbs_sge)"
multiplication can also overflow on 32bit systems although it's fine on
64bit systems.
This patch does two things. First, I've re-arranged the condition in
uverbs_request_next_ptr() so that the use controlled variable "len" is on
one side of the comparison by itself without any math. Then I've modified
all the callers to use size_mul() for the multiplications.
Fixes: 67cdb40ca444 ("[IB] uverbs: Implement more commands")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/infiniband/core/uverbs_cmd.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 66b02fbf077a..5ad14c39d48c 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -161,7 +161,7 @@ static const void __user *uverbs_request_next_ptr(struct uverbs_req_iter *iter,
{
const void __user *res = iter->cur;
- if (iter->cur + len > iter->end)
+ if (len > iter->end - iter->cur)
return (void __force __user *)ERR_PTR(-ENOSPC);
iter->cur += len;
return res;
@@ -2008,11 +2008,13 @@ static int ib_uverbs_post_send(struct uverbs_attr_bundle *attrs)
ret = uverbs_request_start(attrs, &iter, &cmd, sizeof(cmd));
if (ret)
return ret;
- wqes = uverbs_request_next_ptr(&iter, cmd.wqe_size * cmd.wr_count);
+ wqes = uverbs_request_next_ptr(&iter, size_mul(cmd.wqe_size,
+ cmd.wr_count));
if (IS_ERR(wqes))
return PTR_ERR(wqes);
- sgls = uverbs_request_next_ptr(
- &iter, cmd.sge_count * sizeof(struct ib_uverbs_sge));
+ sgls = uverbs_request_next_ptr(&iter,
+ size_mul(cmd.sge_count,
+ sizeof(struct ib_uverbs_sge)));
if (IS_ERR(sgls))
return PTR_ERR(sgls);
ret = uverbs_request_finish(&iter);
@@ -2198,11 +2200,11 @@ ib_uverbs_unmarshall_recv(struct uverbs_req_iter *iter, u32 wr_count,
if (wqe_size < sizeof(struct ib_uverbs_recv_wr))
return ERR_PTR(-EINVAL);
- wqes = uverbs_request_next_ptr(iter, wqe_size * wr_count);
+ wqes = uverbs_request_next_ptr(iter, size_mul(wqe_size, wr_count));
if (IS_ERR(wqes))
return ERR_CAST(wqes);
- sgls = uverbs_request_next_ptr(
- iter, sge_count * sizeof(struct ib_uverbs_sge));
+ sgls = uverbs_request_next_ptr(iter, size_mul(sge_count,
+ sizeof(struct ib_uverbs_sge)));
if (IS_ERR(sgls))
return ERR_CAST(sgls);
ret = uverbs_request_finish(iter);
--
2.45.2
