diff options
| author | Jan Engelhardt <jengelh@inai.de> | 2017-12-19 19:09:07 +0100 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-12-22 19:02:44 +1100 |
| commit | 203f45003a3d03eea8fa28d74cfc74c354416fdb (patch) | |
| tree | 8dfa589eb5b0597b555de86fb6949964245d07b4 /drivers | |
| parent | af955bf15d2c27496b0269b1f05c26f758c68314 (diff) | |
crypto: n2 - cure use after free
queue_cache_init is first called for the Control Word Queue
(n2_crypto_probe). At that time, queue_cache[0] is NULL and a new
kmem_cache will be allocated. If the subsequent n2_register_algs call
fails, the kmem_cache will be released in queue_cache_destroy, but
queue_cache_init[0] is not set back to NULL.
So when the Module Arithmetic Unit gets probed next (n2_mau_probe),
queue_cache_init will not allocate a kmem_cache again, but leave it
as its bogus value, causing a BUG() to trigger when queue_cache[0] is
eventually passed to kmem_cache_zalloc:
n2_crypto: Found N2CP at /virtual-devices@100/n2cp@7
n2_crypto: Registered NCS HVAPI version 2.0
called queue_cache_init
n2_crypto: md5 alg registration failed
n2cp f028687c: /virtual-devices@100/n2cp@7: Unable to register algorithms.
called queue_cache_destroy
n2cp: probe of f028687c failed with error -22
n2_crypto: Found NCP at /virtual-devices@100/ncp@6
n2_crypto: Registered NCS HVAPI version 2.0
called queue_cache_init
kernel BUG at mm/slab.c:2993!
Call Trace:
[0000000000604488] kmem_cache_alloc+0x1a8/0x1e0
(inlined) kmem_cache_zalloc
(inlined) new_queue
(inlined) spu_queue_setup
(inlined) handle_exec_unit
[0000000010c61eb4] spu_mdesc_scan+0x1f4/0x460 [n2_crypto]
[0000000010c62b80] n2_mau_probe+0x100/0x220 [n2_crypto]
[000000000084b174] platform_drv_probe+0x34/0xc0
Cc: <stable@vger.kernel.org>
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/crypto/n2_core.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/crypto/n2_core.c b/drivers/crypto/n2_core.c index 48de52cf2ecc..662e709812cc 100644 --- a/drivers/crypto/n2_core.c +++ b/drivers/crypto/n2_core.c @@ -1625,6 +1625,7 @@ static int queue_cache_init(void) CWQ_ENTRY_SIZE, 0, NULL); if (!queue_cache[HV_NCS_QTYPE_CWQ - 1]) { kmem_cache_destroy(queue_cache[HV_NCS_QTYPE_MAU - 1]); + queue_cache[HV_NCS_QTYPE_MAU - 1] = NULL; return -ENOMEM; } return 0; @@ -1634,6 +1635,8 @@ static void queue_cache_destroy(void) { kmem_cache_destroy(queue_cache[HV_NCS_QTYPE_MAU - 1]); kmem_cache_destroy(queue_cache[HV_NCS_QTYPE_CWQ - 1]); + queue_cache[HV_NCS_QTYPE_MAU - 1] = NULL; + queue_cache[HV_NCS_QTYPE_CWQ - 1] = NULL; } static long spu_queue_register_workfn(void *arg) |