[bug report] crypto: chcr - Select device in Round Robin fashion

[bug report] crypto: chcr - Select device in Round Robin fashion

[Dan Carpenter]

Hello Harsh Jain,

The patch 14c19b178a01: "crypto: chcr - Select device in Round Robin
fashion" from Jun 15, 2017, leads to the following static checker
warning:

	drivers/crypto/chelsio/chcr_core.c:163 chcr_uld_add()
	warn: overwrite may leak 'u_ctx'

drivers/crypto/chelsio/chcr_core.c
   152  static void *chcr_uld_add(const struct cxgb4_lld_info *lld)
   153  {
   154          struct uld_ctx *u_ctx;
   155  
   156          /* Create the device and add it in the device list */
   157          u_ctx = kzalloc(sizeof(*u_ctx), GFP_KERNEL);
   158          if (!u_ctx) {
   159                  u_ctx = ERR_PTR(-ENOMEM);
   160                  goto out;
   161          }
   162          if (!(lld->ulp_crypto & ULP_CRYPTO_LOOKASIDE)) {

Sure, we could move this check before the allocation, to prevent the
leak but is -ENOMEM really the right error code?  It feels like -EINVAL
with a WARN_ON_ONCE() message would be better but I don't really
understand this code.

   163                  u_ctx = ERR_PTR(-ENOMEM);
   164                  goto out;
   165          }
   166          u_ctx->lldi = *lld;
   167  out:
   168          return u_ctx;
   169  }

regards,
dan carpenter

Re: [bug report] crypto: chcr - Select device in Round Robin fashion

[Harsh Jain]

On 20-07-2017 16:02, Dan Carpenter wrote:
> Hello Harsh Jain,
>
> The patch 14c19b178a01: "crypto: chcr - Select device in Round Robin
> fashion" from Jun 15, 2017, leads to the following static checker
> warning:
>
> 	drivers/crypto/chelsio/chcr_core.c:163 chcr_uld_add()
> 	warn: overwrite may leak 'u_ctx'
>
> drivers/crypto/chelsio/chcr_core.c
>    152  static void *chcr_uld_add(const struct cxgb4_lld_info *lld)
>    153  {
>    154          struct uld_ctx *u_ctx;
>    155  
>    156          /* Create the device and add it in the device list */
>    157          u_ctx = kzalloc(sizeof(*u_ctx), GFP_KERNEL);
>    158          if (!u_ctx) {
>    159                  u_ctx = ERR_PTR(-ENOMEM);
>    160                  goto out;
>    161          }
>    162          if (!(lld->ulp_crypto & ULP_CRYPTO_LOOKASIDE)) {
>
> Sure, we could move this check before the allocation, to prevent the
> leak but is -ENOMEM really the right error code?  It feels like -EINVAL
> with a WARN_ON_ONCE() message would be better but I don't really
> understand this code.
Will fix both issues in next change set. Thanks.
>
>    163                  u_ctx = ERR_PTR(-ENOMEM);
>    164                  goto out;
>    165          }
>    166          u_ctx->lldi = *lld;
>    167  out:
>    168          return u_ctx;
>    169  }
>
> regards,
> dan carpenter