IB/core: disallow registering 0-sized memory region

If ib_umem_get() is called with a size equal to 0 and an
non-page aligned address, one page will be pinned and a
0-sized umem will be returned to the caller.

This should not be allowed: it's not expected for a memory
region to have a size equal to 0.

This patch adds a check to explicitly refuse to register
a 0-sized region.

Link: http://mid.gmane.org/cover.1428929103.git.ydroneaud@opteya.com
Cc: <stable@vger.kernel.org>
Cc: Shachar Raindel <raindel@mellanox.com>
Cc: Jack Morgenstein <jackm@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Yann Droneaud 2015-04-13 14:56:22 +02:00 committed by Doug Ledford
parent c841e12add
commit 8abaae62f3

View file

@ -99,6 +99,9 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
if (dmasync)
dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);
if (!size)
return ERR_PTR(-EINVAL);
/*
* If the combination of the addr and size requested for this memory
* region causes an integer overflow, return error.