* [PATCH] genetlink: prevent memory leak in netlbl_unlabel_defconf
@ 2019-09-25 22:10 Navid Emamdoost
2019-09-25 23:27 ` Paul Moore
0 siblings, 1 reply; 5+ messages in thread
From: Navid Emamdoost @ 2019-09-25 22:10 UTC (permalink / raw)
Cc: emamd001, kjlu, smccaman, Navid Emamdoost, Paul Moore,
David S. Miller, netdev, linux-security-module, linux-kernel
In netlbl_unlabel_defconf if netlbl_domhsh_add_default fails the
allocated entry should be released.
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
---
net/netlabel/netlabel_unlabeled.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index d2e4ab8d1cb1..c63ec480ee4e 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1541,8 +1541,10 @@ int __init netlbl_unlabel_defconf(void)
entry->family = AF_UNSPEC;
entry->def.type = NETLBL_NLTYPE_UNLABELED;
ret_val = netlbl_domhsh_add_default(entry, &audit_info);
- if (ret_val != 0)
+ if (ret_val != 0) {
+ kfree(entry);
return ret_val;
+ }
netlbl_unlabel_acceptflg_set(1, &audit_info);
--
2.17.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] genetlink: prevent memory leak in netlbl_unlabel_defconf
2019-09-25 22:10 [PATCH] genetlink: prevent memory leak in netlbl_unlabel_defconf Navid Emamdoost
@ 2019-09-25 23:27 ` Paul Moore
2019-09-27 13:15 ` Markus Elfring
0 siblings, 1 reply; 5+ messages in thread
From: Paul Moore @ 2019-09-25 23:27 UTC (permalink / raw)
To: Navid Emamdoost
Cc: emamd001, kjlu, smccaman, David S. Miller, netdev,
linux-security-module, linux-kernel
On Wed, Sep 25, 2019 at 6:10 PM Navid Emamdoost
<navid.emamdoost@gmail.com> wrote:
>
> In netlbl_unlabel_defconf if netlbl_domhsh_add_default fails the
> allocated entry should be released.
>
> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> ---
> net/netlabel/netlabel_unlabeled.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
It is worth noting that netlbl_unlabel_defconf() is only called during
kernel boot by netlbl_init() and if netlbl_unlabel_defconf() returns
an error code the system panics, so this isn't currently a very
practical concern.
That said, netlbl_unlabel_defconf() *should* clean up here just on
principal if nothing else.
Acked-by: Paul Moore <paul@paul-moore.com>
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index d2e4ab8d1cb1..c63ec480ee4e 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -1541,8 +1541,10 @@ int __init netlbl_unlabel_defconf(void)
> entry->family = AF_UNSPEC;
> entry->def.type = NETLBL_NLTYPE_UNLABELED;
> ret_val = netlbl_domhsh_add_default(entry, &audit_info);
> - if (ret_val != 0)
> + if (ret_val != 0) {
> + kfree(entry);
> return ret_val;
> + }
>
> netlbl_unlabel_acceptflg_set(1, &audit_info);
>
> --
> 2.17.1
>
--
paul moore
www.paul-moore.com
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: genetlink: prevent memory leak in netlbl_unlabel_defconf
2019-09-25 23:27 ` Paul Moore
@ 2019-09-27 13:15 ` Markus Elfring
2019-09-27 14:48 ` Paul Moore
0 siblings, 1 reply; 5+ messages in thread
From: Markus Elfring @ 2019-09-27 13:15 UTC (permalink / raw)
To: Paul Moore, Navid Emamdoost, linux-security-module, netdev
Cc: Navid Emamdoost, Kangjie Lu, linux-kernel, kernel-janitors,
Stephen A McCamant, David S. Miller
> > In netlbl_unlabel_defconf if netlbl_domhsh_add_default fails the
> > allocated entry should be released.
…
> That said, netlbl_unlabel_defconf() *should* clean up here just on
> principal if nothing else.
How do you think about to add the tag “Fixes” then?
Regards,
Markus
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: genetlink: prevent memory leak in netlbl_unlabel_defconf
2019-09-27 13:15 ` Markus Elfring
@ 2019-09-27 14:48 ` Paul Moore
2019-09-27 16:14 ` David Miller
0 siblings, 1 reply; 5+ messages in thread
From: Paul Moore @ 2019-09-27 14:48 UTC (permalink / raw)
To: Markus Elfring
Cc: Navid Emamdoost, linux-security-module, netdev, Navid Emamdoost,
Kangjie Lu, linux-kernel, kernel-janitors, Stephen A McCamant,
David S. Miller
On Fri, Sep 27, 2019 at 9:15 AM Markus Elfring <Markus.Elfring@web.de> wrote:
>
> > > In netlbl_unlabel_defconf if netlbl_domhsh_add_default fails the
> > > allocated entry should be released.
> …
> > That said, netlbl_unlabel_defconf() *should* clean up here just on
> > principal if nothing else.
>
> How do you think about to add the tag “Fixes” then?
From what I've seen the "Fixes" tag is typically used by people who
are backporting patches, e.g. the -stable folks, to help decide what
they need to backport. As I mentioned in my previous email this
missing free doesn't actually manifest itself as a practical leak on
any of the existing kernels so there isn't a need to backport this
patch. For that reason I would probably skip the "Fixes" metadata
here, but I don't feel strongly enough about it to object if others
want it. FWIW, I play things very conservatively when talking about
backporting patches to stable kernels; if it doesn't fix a serious
user-visible bug it shouldn't be backported IMHO.
This patch is more of a conceptual fix than a practical fix. Not that
there is anything wrong with this patch, I just think it isn't as
critical as most people would think from reading "memory leak" in the
subject line. Yes, there is a memory leak, but the kernel panics soon
after so it's a bit moot. Further, even if the panic was somehow
skipped (?) the memory leak only happens once during boot; the failed
initialization is undoubtedly going to be far more damaging to the
system than a few lost bytes of memory.
--
paul moore
www.paul-moore.com
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: genetlink: prevent memory leak in netlbl_unlabel_defconf
2019-09-27 14:48 ` Paul Moore
@ 2019-09-27 16:14 ` David Miller
0 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2019-09-27 16:14 UTC (permalink / raw)
To: paul
Cc: Markus.Elfring, navid.emamdoost, linux-security-module, netdev,
emamd001, kjlu, linux-kernel, kernel-janitors, smccaman
From: Paul Moore <paul@paul-moore.com>
Date: Fri, 27 Sep 2019 10:48:54 -0400
> From what I've seen the "Fixes" tag is typically used by people who
> are backporting patches, e.g. the -stable folks, to help decide what
> they need to backport.
Fixes: tags say what commit introduced the code being fixed, whether
it manifests in a real problem or not.
It has nothing directly to do with -stable and exists in it's own right
whether a change gets backported to -stable or not.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2019-09-25 22:10 [PATCH] genetlink: prevent memory leak in netlbl_unlabel_defconf Navid Emamdoost
2019-09-25 23:27 ` Paul Moore
2019-09-27 13:15 ` Markus Elfring
2019-09-27 14:48 ` Paul Moore
2019-09-27 16:14 ` David Miller
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