[PATCH ipsec] xfrm: flush all states in xfrm_state_fini

[PATCH ipsec] xfrm: flush all states in xfrm_state_fini

[Sabrina Dubroca]

While reverting commit f75a2804da39 ("xfrm: destroy xfrm_state
synchronously on net exit path"), I incorrectly changed
xfrm_state_flush's "proto" argument back to IPSEC_PROTO_ANY. This
reverts some of the changes in commit dbb2483b2a46 ("xfrm: clean up
xfrm protocol checks"), and leads to some states not being removed
when we exit the netns.

Pass 0 instead of IPSEC_PROTO_ANY from both xfrm_state_fini
xfrm6_tunnel_net_exit, so that xfrm_state_flush deletes all states.

Fixes: 2a198bbec691 ("Revert "xfrm: destroy xfrm_state synchronously on net exit path"")
Reported-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6641a61fe0e2e89ae8c5
Tested-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
---
 net/ipv6/xfrm6_tunnel.c | 2 +-
 net/xfrm/xfrm_state.c   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv6/xfrm6_tunnel.c b/net/ipv6/xfrm6_tunnel.c
index 5120a763da0d..0a0eeaed0591 100644
--- a/net/ipv6/xfrm6_tunnel.c
+++ b/net/ipv6/xfrm6_tunnel.c
@@ -334,7 +334,7 @@ static void __net_exit xfrm6_tunnel_net_exit(struct net *net)
 	struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
 	unsigned int i;
 
-	xfrm_state_flush(net, IPSEC_PROTO_ANY, false);
+	xfrm_state_flush(net, 0, false);
 	xfrm_flush_gc();
 
 	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 97ff756191ba..5f1da305eea8 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -3278,7 +3278,7 @@ void xfrm_state_fini(struct net *net)
 	unsigned int sz;
 
 	flush_work(&net->xfrm.state_hash_work);
-	xfrm_state_flush(net, IPSEC_PROTO_ANY, false);
+	xfrm_state_flush(net, 0, false);
 	flush_work(&xfrm_state_gc_work);
 
 	WARN_ON(!list_empty(&net->xfrm.state_all));
-- 
2.50.0

Re: [PATCH ipsec] xfrm: flush all states in xfrm_state_fini

[Simon Horman]

On Mon, Aug 04, 2025 at 11:05:43AM +0200, Sabrina Dubroca wrote:
> While reverting commit f75a2804da39 ("xfrm: destroy xfrm_state
> synchronously on net exit path"), I incorrectly changed
> xfrm_state_flush's "proto" argument back to IPSEC_PROTO_ANY. This
> reverts some of the changes in commit dbb2483b2a46 ("xfrm: clean up
> xfrm protocol checks"), and leads to some states not being removed
> when we exit the netns.
> 
> Pass 0 instead of IPSEC_PROTO_ANY from both xfrm_state_fini
> xfrm6_tunnel_net_exit, so that xfrm_state_flush deletes all states.
> 
> Fixes: 2a198bbec691 ("Revert "xfrm: destroy xfrm_state synchronously on net exit path"")
> Reported-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=6641a61fe0e2e89ae8c5
> Tested-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com
> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>

Thanks Sabrina,

Looking over Git history my understanding matches
what you describe in the commit message.

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH ipsec] xfrm: flush all states in xfrm_state_fini

[Steffen Klassert]

On Mon, Aug 04, 2025 at 11:05:43AM +0200, Sabrina Dubroca wrote:
> While reverting commit f75a2804da39 ("xfrm: destroy xfrm_state
> synchronously on net exit path"), I incorrectly changed
> xfrm_state_flush's "proto" argument back to IPSEC_PROTO_ANY. This
> reverts some of the changes in commit dbb2483b2a46 ("xfrm: clean up
> xfrm protocol checks"), and leads to some states not being removed
> when we exit the netns.
> 
> Pass 0 instead of IPSEC_PROTO_ANY from both xfrm_state_fini
> xfrm6_tunnel_net_exit, so that xfrm_state_flush deletes all states.
> 
> Fixes: 2a198bbec691 ("Revert "xfrm: destroy xfrm_state synchronously on net exit path"")
> Reported-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=6641a61fe0e2e89ae8c5
> Tested-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com
> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>

Applied, thanks a lot Sabrina!