4.20-stable review patch. If anyone has any objections, please let me know.
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From: Wenwen Wang wang6495@umn.edu
commit 7172122be6a4712d699da4d261f92aa5ab3a78b8 upstream.
In crypto_alloc_context(), a DMA pool is allocated through dma_pool_alloc() to hold the crypto context. The meta data of the DMA pool, including the pool used for the allocation 'ndev->ctx_pool' and the base address of the DMA pool used by the device 'dma', are then stored to the beginning of the pool. These meta data are eventually used in crypto_free_context() to free the DMA pool through dma_pool_free(). However, given that the DMA pool can also be accessed by the device, a malicious device can modify these meta data, especially when the device is controlled to deploy an attack. This can cause an unexpected DMA pool free failure.
To avoid the above issue, this patch introduces a new structure crypto_ctx_hdr and a new field chdr in the structure nitrox_crypto_ctx hold the meta data information of the DMA pool after the allocation. Note that the original structure ctx_hdr is not changed to ensure the compatibility.
Cc: stable@vger.kernel.org Signed-off-by: Wenwen Wang wang6495@umn.edu Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/crypto/cavium/nitrox/nitrox_algs.c | 12 +++++++----- drivers/crypto/cavium/nitrox/nitrox_lib.c | 22 +++++++++++++++++----- drivers/crypto/cavium/nitrox/nitrox_req.h | 7 +++++++ 3 files changed, 31 insertions(+), 10 deletions(-)
--- a/drivers/crypto/cavium/nitrox/nitrox_algs.c +++ b/drivers/crypto/cavium/nitrox/nitrox_algs.c @@ -73,7 +73,7 @@ static int flexi_aes_keylen(int keylen) static int nitrox_skcipher_init(struct crypto_skcipher *tfm) { struct nitrox_crypto_ctx *nctx = crypto_skcipher_ctx(tfm); - void *fctx; + struct crypto_ctx_hdr *chdr;
/* get the first device */ nctx->ndev = nitrox_get_first_device(); @@ -81,12 +81,14 @@ static int nitrox_skcipher_init(struct c return -ENODEV;
/* allocate nitrox crypto context */ - fctx = crypto_alloc_context(nctx->ndev); - if (!fctx) { + chdr = crypto_alloc_context(nctx->ndev); + if (!chdr) { nitrox_put_device(nctx->ndev); return -ENOMEM; } - nctx->u.ctx_handle = (uintptr_t)fctx; + nctx->chdr = chdr; + nctx->u.ctx_handle = (uintptr_t)((u8 *)chdr->vaddr + + sizeof(struct ctx_hdr)); crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(tfm) + sizeof(struct nitrox_kcrypt_request)); return 0; @@ -102,7 +104,7 @@ static void nitrox_skcipher_exit(struct
memset(&fctx->crypto, 0, sizeof(struct crypto_keys)); memset(&fctx->auth, 0, sizeof(struct auth_keys)); - crypto_free_context((void *)fctx); + crypto_free_context((void *)nctx->chdr); } nitrox_put_device(nctx->ndev);
--- a/drivers/crypto/cavium/nitrox/nitrox_lib.c +++ b/drivers/crypto/cavium/nitrox/nitrox_lib.c @@ -158,12 +158,19 @@ static void destroy_crypto_dma_pool(stru void *crypto_alloc_context(struct nitrox_device *ndev) { struct ctx_hdr *ctx; + struct crypto_ctx_hdr *chdr; void *vaddr; dma_addr_t dma;
+ chdr = kmalloc(sizeof(*chdr), GFP_KERNEL); + if (!chdr) + return NULL; + vaddr = dma_pool_zalloc(ndev->ctx_pool, GFP_KERNEL, &dma); - if (!vaddr) + if (!vaddr) { + kfree(chdr); return NULL; + }
/* fill meta data */ ctx = vaddr; @@ -171,7 +178,11 @@ void *crypto_alloc_context(struct nitrox ctx->dma = dma; ctx->ctx_dma = dma + sizeof(struct ctx_hdr);
- return ((u8 *)vaddr + sizeof(struct ctx_hdr)); + chdr->pool = ndev->ctx_pool; + chdr->dma = dma; + chdr->vaddr = vaddr; + + return chdr; }
/** @@ -180,13 +191,14 @@ void *crypto_alloc_context(struct nitrox */ void crypto_free_context(void *ctx) { - struct ctx_hdr *ctxp; + struct crypto_ctx_hdr *ctxp;
if (!ctx) return;
- ctxp = (struct ctx_hdr *)((u8 *)ctx - sizeof(struct ctx_hdr)); - dma_pool_free(ctxp->pool, ctxp, ctxp->dma); + ctxp = ctx; + dma_pool_free(ctxp->pool, ctxp->vaddr, ctxp->dma); + kfree(ctxp); }
/** --- a/drivers/crypto/cavium/nitrox/nitrox_req.h +++ b/drivers/crypto/cavium/nitrox/nitrox_req.h @@ -181,12 +181,19 @@ struct flexi_crypto_context { struct auth_keys auth; };
+struct crypto_ctx_hdr { + struct dma_pool *pool; + dma_addr_t dma; + void *vaddr; +}; + struct nitrox_crypto_ctx { struct nitrox_device *ndev; union { u64 ctx_handle; struct flexi_crypto_context *fctx; } u; + struct crypto_ctx_hdr *chdr; };
struct nitrox_kcrypt_request {