diff mbox series

[PATCHv2,ipsec] xfrm: set dst dev to blackhole_netdev instead of loopback_dev in ifdown

Message ID e8c87482998ca6fcdab214f5a9d582899ec0c648.1652665047.git.lucien.xin@gmail.com (mailing list archive)
State Accepted
Commit 4d33ab08c0af140752a46f227a6bf97dab1e17b4
Delegated to: Netdev Maintainers
Headers show
Series [PATCHv2,ipsec] xfrm: set dst dev to blackhole_netdev instead of loopback_dev in ifdown | expand

Checks

Context Check Description
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 12 this patch: 12
netdev/cc_maintainers warning 2 maintainers not CCed: herbert@gondor.apana.org.au pabeni@redhat.com
netdev/build_clang success Errors and warnings before: 9 this patch: 9
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 12 this patch: 12
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Xin Long May 16, 2022, 1:37 a.m. UTC
The global blackhole_netdev has replaced pernet loopback_dev to become the
one given to the object that holds an netdev when ifdown in many places of
ipv4 and ipv6 since commit 8d7017fd621d ("blackhole_netdev: use
blackhole_netdev to invalidate dst entries").

Especially after commit faab39f63c1f ("net: allow out-of-order netdev
unregistration"), it's no longer safe to use loopback_dev that may be
freed before other netdev.

This patch is to set dst dev to blackhole_netdev instead of loopback_dev
in ifdown.

v1->v2:
  - add Fixes tag as Eric suggested.

Fixes: faab39f63c1f ("net: allow out-of-order netdev unregistration")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/xfrm/xfrm_policy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Eric Dumazet May 16, 2022, 2:28 a.m. UTC | #1
On Sun, May 15, 2022 at 6:37 PM Xin Long <lucien.xin@gmail.com> wrote:
>
> The global blackhole_netdev has replaced pernet loopback_dev to become the
> one given to the object that holds an netdev when ifdown in many places of
> ipv4 and ipv6 since commit 8d7017fd621d ("blackhole_netdev: use
> blackhole_netdev to invalidate dst entries").
>
> Especially after commit faab39f63c1f ("net: allow out-of-order netdev
> unregistration"), it's no longer safe to use loopback_dev that may be
> freed before other netdev.
>
> This patch is to set dst dev to blackhole_netdev instead of loopback_dev
> in ifdown.
>

Reviewed-by: Eric Dumazet <edumazet@google.com>
patchwork-bot+netdevbpf@kernel.org May 17, 2022, 9:20 a.m. UTC | #2
Hello:

This patch was applied to netdev/net.git (master)
by Paolo Abeni <pabeni@redhat.com>:

On Sun, 15 May 2022 21:37:27 -0400 you wrote:
> The global blackhole_netdev has replaced pernet loopback_dev to become the
> one given to the object that holds an netdev when ifdown in many places of
> ipv4 and ipv6 since commit 8d7017fd621d ("blackhole_netdev: use
> blackhole_netdev to invalidate dst entries").
> 
> Especially after commit faab39f63c1f ("net: allow out-of-order netdev
> unregistration"), it's no longer safe to use loopback_dev that may be
> freed before other netdev.
> 
> [...]

Here is the summary with links:
  - [PATCHv2,ipsec] xfrm: set dst dev to blackhole_netdev instead of loopback_dev in ifdown
    https://git.kernel.org/netdev/net/c/4d33ab08c0af

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 00bd0ecff5a1..f1876ea61fdc 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -3744,7 +3744,7 @@  static int stale_bundle(struct dst_entry *dst)
 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
 {
 	while ((dst = xfrm_dst_child(dst)) && dst->xfrm && dst->dev == dev) {
-		dst->dev = dev_net(dev)->loopback_dev;
+		dst->dev = blackhole_netdev;
 		dev_hold(dst->dev);
 		dev_put(dev);
 	}