[PATCH v2] xfrm: fix memory leak in xfrm_add_acquire()

[PATCH v2] xfrm: fix memory leak in xfrm_add_acquire()

[Zilin Guan]

The xfrm_add_acquire() function constructs an xfrm policy by calling
xfrm_policy_construct(). This allocates the policy structure and
potentially associates a security context and a device policy with it.

However, at the end of the function, the policy object is freed using
only kfree() . This skips the necessary cleanup for the security context
and device policy, leading to a memory leak.

To fix this, invoke the proper cleanup functions xfrm_dev_policy_delete(),
xfrm_dev_policy_free(), and security_xfrm_policy_free() before freeing the
policy object. This approach mirrors the error handling path in
xfrm_add_policy(), ensuring that all associated resources are correctly
released.

Fixes: 980ebd25794f ("[IPSEC]: Sync series - acquire insert")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
---
Changes in v2:
- Use the correct cleanup functions as per xfrm_add_policy().
---
 net/xfrm/xfrm_user.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 010c9e6638c0..441d5fa319f4 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -3035,6 +3035,9 @@ static int xfrm_add_acquire(struct sk_buff *skb, struct nlmsghdr *nlh,
 	}
 
 	xfrm_state_free(x);
+	xfrm_dev_policy_delete(xp);
+	xfrm_dev_policy_free(xp);
+	security_xfrm_policy_free(xp->security);
 	kfree(xp);
 
 	return 0;
-- 
2.34.1

Re: [PATCH v2] xfrm: fix memory leak in xfrm_add_acquire()

[Sabrina Dubroca]

note: the subject prefix should be [PATCH ipsec vX] for fixes to the
ipsec tree. (sorry, I forgot to mention that in v1)

2025-11-10, 06:41:25 +0000, Zilin Guan wrote:
> The xfrm_add_acquire() function constructs an xfrm policy by calling
> xfrm_policy_construct(). This allocates the policy structure and
> potentially associates a security context and a device policy with it.
> 
> However, at the end of the function, the policy object is freed using
> only kfree() . This skips the necessary cleanup for the security context
> and device policy, leading to a memory leak.
> 
> To fix this, invoke the proper cleanup functions xfrm_dev_policy_delete(),
> xfrm_dev_policy_free(), and security_xfrm_policy_free() before freeing the
> policy object. This approach mirrors the error handling path in
> xfrm_add_policy(), ensuring that all associated resources are correctly
> released.
> 
> Fixes: 980ebd25794f ("[IPSEC]: Sync series - acquire insert")
> Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
> ---
> Changes in v2:
> - Use the correct cleanup functions as per xfrm_add_policy().
> ---
>  net/xfrm/xfrm_user.c | 3 +++
>  1 file changed, 3 insertions(+)

Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>

-- 
Sabrina

Re: [PATCH v2] xfrm: fix memory leak in xfrm_add_acquire()

[Steffen Klassert]

On Tue, Nov 11, 2025 at 12:07:40AM +0100, Sabrina Dubroca wrote:
> note: the subject prefix should be [PATCH ipsec vX] for fixes to the
> ipsec tree. (sorry, I forgot to mention that in v1)
> 
> 2025-11-10, 06:41:25 +0000, Zilin Guan wrote:
> > The xfrm_add_acquire() function constructs an xfrm policy by calling
> > xfrm_policy_construct(). This allocates the policy structure and
> > potentially associates a security context and a device policy with it.
> > 
> > However, at the end of the function, the policy object is freed using
> > only kfree() . This skips the necessary cleanup for the security context
> > and device policy, leading to a memory leak.
> > 
> > To fix this, invoke the proper cleanup functions xfrm_dev_policy_delete(),
> > xfrm_dev_policy_free(), and security_xfrm_policy_free() before freeing the
> > policy object. This approach mirrors the error handling path in
> > xfrm_add_policy(), ensuring that all associated resources are correctly
> > released.
> > 
> > Fixes: 980ebd25794f ("[IPSEC]: Sync series - acquire insert")
> > Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
> > ---
> > Changes in v2:
> > - Use the correct cleanup functions as per xfrm_add_policy().
> > ---
> >  net/xfrm/xfrm_user.c | 3 +++
> >  1 file changed, 3 insertions(+)
> 
> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>

Applied to the ipsec tree, thanks everyone!