From: Shachar Raindel Date: Wed, 18 Mar 2015 17:39:08 +0000 (+0000) Subject: IB/uverbs: Prevent integer overflow in ib_umem_get address arithmetic X-Git-Tag: v4.0-rc7~16^2 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8494057ab5e4;p=karo-tx-linux.git IB/uverbs: Prevent integer overflow in ib_umem_get address arithmetic 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 Cc: Signed-off-by: Shachar Raindel Signed-off-by: Jack Morgenstein Signed-off-by: Or Gerlitz Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index aec7a6aa2951..8c014b5dab4c 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -99,6 +99,14 @@ 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);