Hi Russel, On Fri, 09 Oct 2015 20:43:43 +0100 Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> wrote: > When a AF_ALG fd is accepted a second time (hence hash_accept() is > used), hash_accept_parent() allocates a new private context using > sock_kmalloc(). This context is uninitialised. After use of the new > fd, we eventually end up with the kernel complaining: > > marvell-cesa f1090000.crypto: dma_pool_free cesa_padding, c0627770/0 (bad dma) > > where c0627770 is a random address. Poisoning the memory allocated by > the above sock_kmalloc() produces kernel oopses within the marvell hash > code, particularly the interrupt handling. > > The following simplfied call sequence occurs: > > hash_accept() > crypto_ahash_export() > marvell hash export function > af_alg_accept() > hash_accept_parent() <== allocates uninitialised struct hash_ctx > crypto_ahash_import() > marvell hash import function > > hash_ctx contains the struct mv_cesa_ahash_req in its req.__ctx member, > and, as the marvell hash import function only partially initialises > this structure, we end up with a lot of members which are left with > whatever data was in memory prior to sock_kmalloc(). > > Add zero-initialisation of this structure. Maybe you should also change your commit message since this patch no longer initializes the req struct to zero, otherwise Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> > > Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> > --- > drivers/crypto/marvell/hash.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/crypto/marvell/hash.c b/drivers/crypto/marvell/hash.c > index a259aced3b42..458867ce9515 100644 > --- a/drivers/crypto/marvell/hash.c > +++ b/drivers/crypto/marvell/hash.c > @@ -831,6 +831,10 @@ static int mv_cesa_md5_import(struct ahash_request *req, const void *in) > unsigned int cache_ptr; > int ret; > > + ret = crypto_ahash_init(req); > + if (ret) > + return ret; > + > creq->len = in_state->byte_count; > memcpy(creq->state, in_state->hash, digsize); > creq->cache_ptr = 0; > @@ -921,6 +925,10 @@ static int mv_cesa_sha1_import(struct ahash_request *req, const void *in) > unsigned int cache_ptr; > int ret; > > + ret = crypto_ahash_init(req); > + if (ret) > + return ret; > + > creq->len = in_state->count; > memcpy(creq->state, in_state->state, digsize); > creq->cache_ptr = 0; > @@ -1022,6 +1030,10 @@ static int mv_cesa_sha256_import(struct ahash_request *req, const void *in) > unsigned int cache_ptr; > int ret; > > + ret = crypto_ahash_init(req); > + if (ret) > + return ret; > + > creq->len = in_state->count; > memcpy(creq->state, in_state->state, digsize); > creq->cache_ptr = 0; -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
