| Message ID | 20171219180907.12895-1-jengelh@inai.de (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
From: Jan Engelhardt <jengelh@inai.de> Date: Tue, 19 Dec 2017 19:09:07 +0100 > 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: ... > Signed-off-by: Jan Engelhardt <jengelh@inai.de> Acked-by: David S. Miller <davem@davemloft.net>
Jan Engelhardt <jengelh@inai.de> wrote: > 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 > > Signed-off-by: Jan Engelhardt <jengelh@inai.de> Patch applied. Thanks.
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)
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 Signed-off-by: Jan Engelhardt <jengelh@inai.de> --- drivers/crypto/n2_core.c | 3 +++ 1 file changed, 3 insertions(+)