The assignment of the op_code in the virtio_crypto_create_asym_session
function was moved before its usage to ensure it is correctly set.
Previously, if the function failed during the key_len check, the op_code
did not have a proper value, causing virtio_crypto_free_create_session_req
to not free the memory correctly, leading to a memory leak.

By setting the op_code before performing any checks, we ensure that
virtio_crypto_free_create_session_req has the correct context to
perform cleanup operations properly, thus preventing memory leaks.

ASAN log:
==3055068==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 512 byte(s) in 1 object(s) allocated from:
    #0 0x5586a75e6ddd in malloc llvm/compiler-rt/lib/asan/asan_malloc_linux.cpp:129:3
    #1 0x7fb6b63b6738 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x5e738)
    #2 0x5586a864bbde in virtio_crypto_handle_ctrl hw/virtio/virtio-crypto.c:407:19
    #3 0x5586a94fc84c in virtio_queue_notify_vq hw/virtio/virtio.c:2277:9
    #4 0x5586a94fc0a2 in virtio_queue_host_notifier_read hw/virtio/virtio.c:3641:9

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
---
Changes in v2:
- Fix the whitespace in title
---
 hw/virtio/virtio-crypto.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c
index bbe8aa4b99..5034768bff 100644
--- a/hw/virtio/virtio-crypto.c
+++ b/hw/virtio/virtio-crypto.c
@@ -205,6 +205,7 @@ virtio_crypto_create_asym_session(VirtIOCrypto *vcrypto,
     int queue_index;
     uint32_t algo, keytype, keylen;
 
+    sreq->info.op_code = opcode;
     algo = ldl_le_p(&sess_req->para.algo);
     keytype = ldl_le_p(&sess_req->para.keytype);
     keylen = ldl_le_p(&sess_req->para.keylen);
@@ -224,7 +225,6 @@ virtio_crypto_create_asym_session(VirtIOCrypto *vcrypto,
         iov_discard_front(&iov, &out_num, keylen);
     }
 
-    sreq->info.op_code = opcode;
     asym_info = &sreq->info.u.asym_sess_info;
     asym_info->algo = algo;
     asym_info->keytype = keytype;
-- 
2.34.1

On Tue, Jul 02, 2024 at 11:05:19PM +0200, Zheyu Ma wrote:
> The assignment of the op_code in the virtio_crypto_create_asym_session
> function was moved before its usage to ensure it is correctly set.
> Previously, if the function failed during the key_len check, the op_code
> did not have a proper value, causing virtio_crypto_free_create_session_req
> to not free the memory correctly, leading to a memory leak.
> 
> By setting the op_code before performing any checks, we ensure that
> virtio_crypto_free_create_session_req has the correct context to
> perform cleanup operations properly, thus preventing memory leaks.
> 
> ASAN log:
> ==3055068==ERROR: LeakSanitizer: detected memory leaks
> Direct leak of 512 byte(s) in 1 object(s) allocated from:
>     #0 0x5586a75e6ddd in malloc llvm/compiler-rt/lib/asan/asan_malloc_linux.cpp:129:3
>     #1 0x7fb6b63b6738 in g_malloc (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x5e738)
>     #2 0x5586a864bbde in virtio_crypto_handle_ctrl hw/virtio/virtio-crypto.c:407:19
>     #3 0x5586a94fc84c in virtio_queue_notify_vq hw/virtio/virtio.c:2277:9
>     #4 0x5586a94fc0a2 in virtio_queue_host_notifier_read hw/virtio/virtio.c:3641:9
> 
> Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>

see my comments on v1.

> ---
> Changes in v2:
> - Fix the whitespace in title
> ---
>  hw/virtio/virtio-crypto.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c
> index bbe8aa4b99..5034768bff 100644
> --- a/hw/virtio/virtio-crypto.c
> +++ b/hw/virtio/virtio-crypto.c
> @@ -205,6 +205,7 @@ virtio_crypto_create_asym_session(VirtIOCrypto *vcrypto,
>      int queue_index;
>      uint32_t algo, keytype, keylen;
>  
> +    sreq->info.op_code = opcode;
>      algo = ldl_le_p(&sess_req->para.algo);
>      keytype = ldl_le_p(&sess_req->para.keytype);
>      keylen = ldl_le_p(&sess_req->para.keylen);
> @@ -224,7 +225,6 @@ virtio_crypto_create_asym_session(VirtIOCrypto *vcrypto,
>          iov_discard_front(&iov, &out_num, keylen);
>      }
>  
> -    sreq->info.op_code = opcode;
>      asym_info = &sreq->info.u.asym_sess_info;
>      asym_info->algo = algo;
>      asym_info->keytype = keytype;
> -- 
> 2.34.1