IB/uverbs: Prevent integer overflow in ib_umem_get address arithmetic

commit 8494057ab5e40df590ef6ef7d66324d3ae33356b upstream.

Properly verify that the resulting page aligned end address is larger
than both the start address and the length of the memory area requested.

Both the start and length arguments for ib_umem_get are controlled by
the user. A misbehaving user can provide values which will cause an
integer overflow when calculating the page aligned end address.

This overflow can cause also miscalculation of the number of pages
mapped, and additional logic issues.

Addresses: CVE-2014-8159
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 485f16b743d98527620396639b73d7214006f3c7)

Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 6f7c096abf1366007cb2352c211a0f8eba132d69..2ecd8d6115aadfaed1ceb17cc65bfc029ff585f7 100644 (file)
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -92,6 +92,14 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
        if (dmasync)
                dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
 
+       /*
+        * If the combination of the addr and size requested for this memory
+        * region causes an integer overflow, return error.
+        */
+       if ((PAGE_ALIGN(addr + size) <= size) ||
+           (PAGE_ALIGN(addr + size) <= addr))
+               return ERR_PTR(-EINVAL);
+
        if (!can_do_mlock())
                return ERR_PTR(-EPERM);