| From | lizf@kernel ... | Subject | [PATCH 3.4 046/146] IB/core: disallow registering 0-sized memory region | Date | Tue, 15 Sep 2015 17:02:41 +0800 |
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From: Yann Droneaud <ydroneaud@opteya.com>
3.4.109-rc1 review patch. If anyone has any objections, please let me know.
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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 <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> Signed-off-by: Zefan Li <lizefan@huawei.com> --- 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 d0254be..c1fef27 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. -- 1.9.1
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