diff options
| author | Jan Stancek <jstancek@redhat.com> | 2016-09-28 16:38:37 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2016-10-02 22:33:43 +0800 |
| commit | 7bcb87bca2f51226f3ec382fcd3ff52cc15747bb (patch) | |
| tree | 07bb151f7e7dd849a87822e33506f15925c28419 /crypto/testmgr.c | |
| parent | 3387879524ec07fd9ba371eddd17e717abdd5e4f (diff) | |
| download | lwn-7bcb87bca2f51226f3ec382fcd3ff52cc15747bb.tar.gz lwn-7bcb87bca2f51226f3ec382fcd3ff52cc15747bb.zip | |
crypto: testmgr - add guard to dst buffer for ahash_export
Add a guard to 'state' buffer and warn if its consistency after
call to crypto_ahash_export() changes, so that any write that
goes beyond advertised statesize (and thus causing potential
memory corruption [1]) is more visible.
[1] https://marc.info/?l=linux-crypto-vger&m=147467656516085
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Marcelo Cerri <marcelo.cerri@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/testmgr.c')
| -rw-r--r-- | crypto/testmgr.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/crypto/testmgr.c b/crypto/testmgr.c index 0b01c3d062e2..62dffa0028ac 100644 --- a/crypto/testmgr.c +++ b/crypto/testmgr.c @@ -209,16 +209,19 @@ static int ahash_partial_update(struct ahash_request **preq, char *state; struct ahash_request *req; int statesize, ret = -EINVAL; + const char guard[] = { 0x00, 0xba, 0xad, 0x00 }; req = *preq; statesize = crypto_ahash_statesize( crypto_ahash_reqtfm(req)); - state = kmalloc(statesize, GFP_KERNEL); + state = kmalloc(statesize + sizeof(guard), GFP_KERNEL); if (!state) { pr_err("alt: hash: Failed to alloc state for %s\n", algo); goto out_nostate; } + memcpy(state + statesize, guard, sizeof(guard)); ret = crypto_ahash_export(req, state); + WARN_ON(memcmp(state + statesize, guard, sizeof(guard))); if (ret) { pr_err("alt: hash: Failed to export() for %s\n", algo); goto out; |