* [PATCH] nfsd: Fix a memory leak in an error handling path
@ 2022-08-26 10:24 Christophe JAILLET
2022-08-26 10:41 ` Jeff Layton
2022-08-26 11:08 ` Dan Carpenter
0 siblings, 2 replies; 6+ messages in thread
From: Christophe JAILLET @ 2022-08-26 10:24 UTC (permalink / raw)
To: Chuck Lever, Jeff Layton, J. Bruce Fields, Scott Mayhew
Cc: linux-kernel, kernel-janitors, Christophe JAILLET, linux-nfs
If this memdup_user() call fails, the memory allocated in a previous call
a few lines above should be freed. Otherwise it leaks.
Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Speculative, untested.
---
fs/nfsd/nfs4recover.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index b29d27eaa8a6..248ff9f4141c 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -815,8 +815,10 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
princhash.data = memdup_user(
&ci->cc_princhash.cp_data,
princhashlen);
- if (IS_ERR_OR_NULL(princhash.data))
+ if (IS_ERR_OR_NULL(princhash.data)) {
+ kfree(name.data);
return -EFAULT;
+ }
princhash.len = princhashlen;
} else
princhash.len = 0;
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] nfsd: Fix a memory leak in an error handling path
2022-08-26 10:24 [PATCH] nfsd: Fix a memory leak in an error handling path Christophe JAILLET
@ 2022-08-26 10:41 ` Jeff Layton
2022-08-26 11:08 ` Dan Carpenter
1 sibling, 0 replies; 6+ messages in thread
From: Jeff Layton @ 2022-08-26 10:41 UTC (permalink / raw)
To: Christophe JAILLET, Chuck Lever, J. Bruce Fields, Scott Mayhew
Cc: linux-kernel, kernel-janitors, linux-nfs
On Fri, 2022-08-26 at 12:24 +0200, Christophe JAILLET wrote:
> If this memdup_user() call fails, the memory allocated in a previous call
> a few lines above should be freed. Otherwise it leaks.
>
> Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Speculative, untested.
> ---
> fs/nfsd/nfs4recover.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> index b29d27eaa8a6..248ff9f4141c 100644
> --- a/fs/nfsd/nfs4recover.c
> +++ b/fs/nfsd/nfs4recover.c
> @@ -815,8 +815,10 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
> princhash.data = memdup_user(
> &ci->cc_princhash.cp_data,
> princhashlen);
> - if (IS_ERR_OR_NULL(princhash.data))
> + if (IS_ERR_OR_NULL(princhash.data)) {
> + kfree(name.data);
> return -EFAULT;
> + }
> princhash.len = princhashlen;
> } else
> princhash.len = 0;
Reviewed-by: Jeff Layton <jlayton@kernel.org>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] nfsd: Fix a memory leak in an error handling path
2022-08-26 10:24 [PATCH] nfsd: Fix a memory leak in an error handling path Christophe JAILLET
2022-08-26 10:41 ` Jeff Layton
@ 2022-08-26 11:08 ` Dan Carpenter
2022-08-30 21:11 ` Chuck Lever III
1 sibling, 1 reply; 6+ messages in thread
From: Dan Carpenter @ 2022-08-26 11:08 UTC (permalink / raw)
To: Christophe JAILLET
Cc: Chuck Lever, Jeff Layton, J. Bruce Fields, Scott Mayhew,
linux-kernel, kernel-janitors, linux-nfs
On Fri, Aug 26, 2022 at 12:24:54PM +0200, Christophe JAILLET wrote:
> If this memdup_user() call fails, the memory allocated in a previous call
> a few lines above should be freed. Otherwise it leaks.
>
> Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Speculative, untested.
> ---
> fs/nfsd/nfs4recover.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> index b29d27eaa8a6..248ff9f4141c 100644
> --- a/fs/nfsd/nfs4recover.c
> +++ b/fs/nfsd/nfs4recover.c
> @@ -815,8 +815,10 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
> princhash.data = memdup_user(
> &ci->cc_princhash.cp_data,
> princhashlen);
> - if (IS_ERR_OR_NULL(princhash.data))
> + if (IS_ERR_OR_NULL(princhash.data)) {
> + kfree(name.data);
> return -EFAULT;
This comment is not directed at you and is not related to your patch.
But memdup_user() never returns NULL, only error pointers. I wrote a
fifteen page blog entry about NULL vs error pointers the other week.
https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
This should propagate the error code from memdup_user() instead of
-EFAULT.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] nfsd: Fix a memory leak in an error handling path
2022-08-26 11:08 ` Dan Carpenter
@ 2022-08-30 21:11 ` Chuck Lever III
2022-08-31 5:06 ` Christophe JAILLET
2022-08-31 5:44 ` Dan Carpenter
0 siblings, 2 replies; 6+ messages in thread
From: Chuck Lever III @ 2022-08-30 21:11 UTC (permalink / raw)
To: Dan Carpenter
Cc: Christophe JAILLET, Jeff Layton, Bruce Fields, Scott Mayhew,
Linux Kernel Mailing List, kernel-janitors,
Linux NFS Mailing List
> On Aug 26, 2022, at 7:08 AM, Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> On Fri, Aug 26, 2022 at 12:24:54PM +0200, Christophe JAILLET wrote:
>> If this memdup_user() call fails, the memory allocated in a previous call
>> a few lines above should be freed. Otherwise it leaks.
>>
>> Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2")
>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> ---
>> Speculative, untested.
>> ---
>> fs/nfsd/nfs4recover.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
>> index b29d27eaa8a6..248ff9f4141c 100644
>> --- a/fs/nfsd/nfs4recover.c
>> +++ b/fs/nfsd/nfs4recover.c
>> @@ -815,8 +815,10 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
>> princhash.data = memdup_user(
>> &ci->cc_princhash.cp_data,
>> princhashlen);
>> - if (IS_ERR_OR_NULL(princhash.data))
>> + if (IS_ERR_OR_NULL(princhash.data)) {
>> + kfree(name.data);
>> return -EFAULT;
>
> This comment is not directed at you and is not related to your patch.
> But memdup_user() never returns NULL, only error pointers. I wrote a
> fifteen page blog entry about NULL vs error pointers the other week.
> https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
> This should propagate the error code from memdup_user() instead of
> -EFAULT.
I take it then that Christophe should redrive this with your suggested
corrections? I haven't applied this yet because I was waiting for
follow-up.
--
Chuck Lever
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] nfsd: Fix a memory leak in an error handling path
2022-08-30 21:11 ` Chuck Lever III
@ 2022-08-31 5:06 ` Christophe JAILLET
2022-08-31 5:44 ` Dan Carpenter
1 sibling, 0 replies; 6+ messages in thread
From: Christophe JAILLET @ 2022-08-31 5:06 UTC (permalink / raw)
To: Chuck Lever, Jeff Layton, J. Bruce Fields, Scott Mayhew
Cc: linux-kernel, kernel-janitors, linux-nfs
Le 30/08/2022 à 23:11, Chuck Lever III a écrit :
>
>
>> On Aug 26, 2022, at 7:08 AM, Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> wrote:
>>
>> On Fri, Aug 26, 2022 at 12:24:54PM +0200, Christophe JAILLET wrote:
>>> If this memdup_user() call fails, the memory allocated in a previous call
>>> a few lines above should be freed. Otherwise it leaks.
>>>
>>> Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2")
>>> Signed-off-by: Christophe JAILLET <christophe.jaillet-39ZsbGIQGT5GWvitb5QawA@public.gmane.org>
>>> ---
>>> Speculative, untested.
>>> ---
>>> fs/nfsd/nfs4recover.c | 4 +++-
>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
>>> index b29d27eaa8a6..248ff9f4141c 100644
>>> --- a/fs/nfsd/nfs4recover.c
>>> +++ b/fs/nfsd/nfs4recover.c
>>> @@ -815,8 +815,10 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
>>> princhash.data = memdup_user(
>>> &ci->cc_princhash.cp_data,
>>> princhashlen);
>>> - if (IS_ERR_OR_NULL(princhash.data))
>>> + if (IS_ERR_OR_NULL(princhash.data)) {
>>> + kfree(name.data);
>>> return -EFAULT;
>>
>> This comment is not directed at you and is not related to your patch.
>> But memdup_user() never returns NULL, only error pointers. I wrote a
>> fifteen page blog entry about NULL vs error pointers the other week.
>> https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
>> This should propagate the error code from memdup_user() instead of
>> -EFAULT.
>
> I take it then that Christophe should redrive this with your suggested
> corrections? I haven't applied this yet because I was waiting for
> follow-up.
>
Ok, I'll send a small serie of 3 patches...
CJ
>
> --
> Chuck Lever
>
>
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] nfsd: Fix a memory leak in an error handling path
2022-08-30 21:11 ` Chuck Lever III
2022-08-31 5:06 ` Christophe JAILLET
@ 2022-08-31 5:44 ` Dan Carpenter
1 sibling, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2022-08-31 5:44 UTC (permalink / raw)
To: Chuck Lever III
Cc: Christophe JAILLET, Jeff Layton, Bruce Fields, Scott Mayhew,
Linux Kernel Mailing List, kernel-janitors,
Linux NFS Mailing List
On Tue, Aug 30, 2022 at 09:11:54PM +0000, Chuck Lever III wrote:
>
>
> > On Aug 26, 2022, at 7:08 AM, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> >
> > On Fri, Aug 26, 2022 at 12:24:54PM +0200, Christophe JAILLET wrote:
> >> If this memdup_user() call fails, the memory allocated in a previous call
> >> a few lines above should be freed. Otherwise it leaks.
> >>
> >> Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2")
> >> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> >> ---
> >> Speculative, untested.
> >> ---
> >> fs/nfsd/nfs4recover.c | 4 +++-
> >> 1 file changed, 3 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> >> index b29d27eaa8a6..248ff9f4141c 100644
> >> --- a/fs/nfsd/nfs4recover.c
> >> +++ b/fs/nfsd/nfs4recover.c
> >> @@ -815,8 +815,10 @@ __cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
> >> princhash.data = memdup_user(
> >> &ci->cc_princhash.cp_data,
> >> princhashlen);
> >> - if (IS_ERR_OR_NULL(princhash.data))
> >> + if (IS_ERR_OR_NULL(princhash.data)) {
> >> + kfree(name.data);
> >> return -EFAULT;
> >
> > This comment is not directed at you and is not related to your patch.
> > But memdup_user() never returns NULL, only error pointers. I wrote a
> > fifteen page blog entry about NULL vs error pointers the other week.
> > https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/
> > This should propagate the error code from memdup_user() instead of
> > -EFAULT.
>
> I take it then that Christophe should redrive this with your suggested
> corrections? I haven't applied this yet because I was waiting for
> follow-up.
No, that's a different thing. If anyone wants to clean that up then it
should be part of a different patch.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 6+ messages in thread
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2022-08-26 10:24 [PATCH] nfsd: Fix a memory leak in an error handling path Christophe JAILLET
2022-08-26 10:41 ` Jeff Layton
2022-08-26 11:08 ` Dan Carpenter
2022-08-30 21:11 ` Chuck Lever III
2022-08-31 5:06 ` Christophe JAILLET
2022-08-31 5:44 ` Dan Carpenter
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