diff mbox series

NFS: remove unneeded check in decode_devicenotify_args()

Message ID 1644920224-24966-1-git-send-email-khoroshilov@ispras.ru (mailing list archive)
State New, archived
Headers show
Series NFS: remove unneeded check in decode_devicenotify_args() | expand

Commit Message

Alexey Khoroshilov Feb. 15, 2022, 10:17 a.m. UTC
Overflow check in not needed anymore after we switch to kmalloc_array().

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Fixes: a4f743a6bb20 ("NFSv4.1: Convert open-coded array allocation calls to kmalloc_array()")
---
 fs/nfs/callback_xdr.c | 4 ----
 1 file changed, 4 deletions(-)

Comments

Anna Schumaker Feb. 16, 2022, 3:30 p.m. UTC | #1
Hi Alexey,

On Tue, Feb 15, 2022 at 5:17 AM Alexey Khoroshilov
<khoroshilov@ispras.ru> wrote:
>
> Overflow check in not needed anymore after we switch to kmalloc_array().

Don't we still need the overflow check since 'n' is used in the
for-loop end condition farther down in this function?

Thanks,
Anna

>
> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
> Fixes: a4f743a6bb20 ("NFSv4.1: Convert open-coded array allocation calls to kmalloc_array()")
> ---
>  fs/nfs/callback_xdr.c | 4 ----
>  1 file changed, 4 deletions(-)
>
> diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
> index f90de8043b0f..8dcb08e1a885 100644
> --- a/fs/nfs/callback_xdr.c
> +++ b/fs/nfs/callback_xdr.c
> @@ -271,10 +271,6 @@ __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
>         n = ntohl(*p++);
>         if (n == 0)
>                 goto out;
> -       if (n > ULONG_MAX / sizeof(*args->devs)) {
> -               status = htonl(NFS4ERR_BADXDR);
> -               goto out;
> -       }
>
>         args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
>         if (!args->devs) {
> --
> 2.7.4
>
Alexey Khoroshilov Feb. 16, 2022, 5:44 p.m. UTC | #2
Hi Anna,

On 16.02.2022 18:30, Anna Schumaker wrote:
> On Tue, Feb 15, 2022 at 5:17 AM Alexey Khoroshilov
> <khoroshilov@ispras.ru> wrote:
>>
>> Overflow check in not needed anymore after we switch to kmalloc_array().
> 
> Don't we still need the overflow check since 'n' is used in the
> for-loop end condition farther down in this function?


It is not, because it will be detected by kmalloc_array(), it returns
NULL and we will go out before the loop:

	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
	if (!args->devs) {
		status = htonl(NFS4ERR_DELAY);
		goto out;
	}

Best regards,
Alexey


>>
>> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
>> Fixes: a4f743a6bb20 ("NFSv4.1: Convert open-coded array allocation calls to kmalloc_array()")
>> ---
>>  fs/nfs/callback_xdr.c | 4 ----
>>  1 file changed, 4 deletions(-)
>>
>> diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
>> index f90de8043b0f..8dcb08e1a885 100644
>> --- a/fs/nfs/callback_xdr.c
>> +++ b/fs/nfs/callback_xdr.c
>> @@ -271,10 +271,6 @@ __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
>>         n = ntohl(*p++);
>>         if (n == 0)
>>                 goto out;
>> -       if (n > ULONG_MAX / sizeof(*args->devs)) {
>> -               status = htonl(NFS4ERR_BADXDR);
>> -               goto out;
>> -       }
>>
>>         args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
>>         if (!args->devs) {
>> --
>> 2.7.4
>>
diff mbox series

Patch

diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index f90de8043b0f..8dcb08e1a885 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -271,10 +271,6 @@  __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
 	n = ntohl(*p++);
 	if (n == 0)
 		goto out;
-	if (n > ULONG_MAX / sizeof(*args->devs)) {
-		status = htonl(NFS4ERR_BADXDR);
-		goto out;
-	}
 
 	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
 	if (!args->devs) {