On Fri, Oct 09, 2015 at 09:50:18PM +0200, Boris Brezillon wrote: > 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 Oops. s/zero-// :) > 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 -- FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- 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
