Re: [PATCH net v3] ipv4: igmp: remove multicast group from hash table on device destruction

From: patchwork-bot+netdevbpf

Date: Tue Jul 07 2026 - 06:27:55 EST


Hello:

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

On Thu, 2 Jul 2026 08:50:14 +0900 you wrote:
> When a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through
> the multicast list and calls ip_ma_put() on each membership, scheduling
> them for RCU reclamation. However, they are not unlinked from the device's
> multicast hash table (mc_hash).
>
> Since the device remains published in dev->ip_ptr until after
> ip_mc_destroy_dev() completes, concurrent RCU readers traversing mc_hash
> can still locate and access the multicast group after its refcount is
> decremented. If the RCU callback runs and frees the group while a reader is
> accessing it, a use-after-free occurs.
>
> [...]

Here is the summary with links:
- [net,v3] ipv4: igmp: remove multicast group from hash table on device destruction
https://git.kernel.org/netdev/net/c/7993211bde16

You are awesome, thank you!
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