infiniband/uverbs: Fix integer overflows (4f7f4dcf) · Commits · 戴 / test

The 'num_sge' variable is verfied to be smaller than the 'sge_count' variable; however, since both are user-controlled it's possible to cause an integer overflow for the kmalloc multiply on 32-bit platforms (num_sge and sge_count are both defined u32). By crafting an input that causes a smaller-than-expected allocation it's possible to write controlled data out-of-bounds. Signed-off-by:

Vlad Tsyrklevich <vlad@tsyrklevich.net> Signed-off-by:

Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/uverbs_cmd.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -2104,9 +2104,13 @@ ssize_t ib_uverbs_destroy_qp(struct ib_uverbs_file *file,

		static void *alloc_wr(size_t wr_size, __u32 num_sge)
		{
		if (num_sge >= (U32_MAX - ALIGN(wr_size, sizeof (struct ib_sge))) /
		sizeof (struct ib_sge))
		return NULL;

		return kmalloc(ALIGN(wr_size, sizeof (struct ib_sge)) +
		num_sge * sizeof (struct ib_sge), GFP_KERNEL);
		};
		}

		ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file,
		struct ib_device *ib_dev,
		@@ -2334,6 +2338,13 @@ static struct ib_recv_wr ib_uverbs_unmarshall_recv(const char __user buf,
		goto err;
		}

		if (user_wr->num_sge >=
		(U32_MAX - ALIGN(sizeof *next, sizeof (struct ib_sge))) /
		sizeof (struct ib_sge)) {
		ret = -EINVAL;
		goto err;
		}

		next = kmalloc(ALIGN(sizeof *next, sizeof (struct ib_sge)) +
		user_wr->num_sge * sizeof (struct ib_sge),
		GFP_KERNEL);

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