* [PATCH net] net: phonet: free phonet_device after RCU grace period
@ 2026-06-04 0:08 Santosh Kalluri
2026-06-08 13:13 ` Simon Horman
0 siblings, 1 reply; 2+ messages in thread
From: Santosh Kalluri @ 2026-06-04 0:08 UTC (permalink / raw)
To: netdev
Cc: Remi Denis-Courmont, Rémi Denis-Courmont, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Simon Horman,
linux-kernel
phonet_device_destroy() removes a phonet_device from the per-net device
list with list_del_rcu(), but frees it immediately. RCU readers walking
the same list can still hold a pointer to the object after it has been
removed, leading to a slab-use-after-free.
Use kfree_rcu(), matching the lifetime rule already used by
phonet_address_del() for the same object type.
Fixes: eeb74a9d45f7 ("Phonet: convert devices list to RCU")
Cc: stable@vger.kernel.org
Signed-off-by: Santosh Kalluri <santosh.kalluri129@gmail.com>
Acked-by: Rémi Denis-Courmont <remi@remlab.net>
---
net/phonet/pn_dev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
index 86325b7fc1b6..ad44831d6745 100644
--- a/net/phonet/pn_dev.c
+++ b/net/phonet/pn_dev.c
@@ -108,7 +108,7 @@ static void phonet_device_destroy(struct net_device *dev)
for_each_set_bit(addr, pnd->addrs, 64)
phonet_address_notify(net, RTM_DELADDR, ifindex, addr);
- kfree(pnd);
+ kfree_rcu(pnd, rcu);
}
}
base-commit: f723ccaff2fb72b71ae8a9fd283f0dee4d9ae7a3
--
2.43.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH net] net: phonet: free phonet_device after RCU grace period
2026-06-04 0:08 [PATCH net] net: phonet: free phonet_device after RCU grace period Santosh Kalluri
@ 2026-06-08 13:13 ` Simon Horman
0 siblings, 0 replies; 2+ messages in thread
From: Simon Horman @ 2026-06-08 13:13 UTC (permalink / raw)
To: Santosh Kalluri
Cc: netdev, Remi Denis-Courmont, Rémi Denis-Courmont,
David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
linux-kernel
On Wed, Jun 03, 2026 at 05:08:43PM -0700, Santosh Kalluri wrote:
> phonet_device_destroy() removes a phonet_device from the per-net device
> list with list_del_rcu(), but frees it immediately. RCU readers walking
> the same list can still hold a pointer to the object after it has been
> removed, leading to a slab-use-after-free.
>
> Use kfree_rcu(), matching the lifetime rule already used by
> phonet_address_del() for the same object type.
>
> Fixes: eeb74a9d45f7 ("Phonet: convert devices list to RCU")
> Cc: stable@vger.kernel.org
> Signed-off-by: Santosh Kalluri <santosh.kalluri129@gmail.com>
> Acked-by: Rémi Denis-Courmont <remi@remlab.net>
Reviewed-by: Simon Horman <horms@kernel.org>
^ permalink raw reply [flat|nested] 2+ messages in thread
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