From 2108cfd4ae3d05d3faad42f2eb51b9a301ad7a24 Mon Sep 17 00:00:00 2001 From: Yann Droneaud Date: Mon, 13 Apr 2015 14:56:22 +0200 Subject: [PATCH] IB/core: disallow registering 0-sized memory region commit 8abaae62f3fdead8f4ce0ab46b4ab93dee39bab2 upstream. 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: Shachar Raindel Cc: Jack Morgenstein Cc: Or Gerlitz Signed-off-by: Yann Droneaud Signed-off-by: Doug Ledford Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/umem.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 055ebebc07d..dccb9aac35c 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -94,6 +94,9 @@ 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. -- 2.20.1