diff options
| author | Lorenzo Bianconi <lorenzo@kernel.org> | 2026-06-02 11:21:04 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-03 19:15:32 -0700 |
| commit | b38cae85d1c45ff189d7ecb6ac36f41cdc3d84d0 (patch) | |
| tree | 8e57ae1de56965c96ae99239162a0513479f6fbc | |
| parent | d20da913083042203221c16bc19bd2f3c12d171f (diff) | |
net: airoha: Fix use-after-free in metadata dst teardown
airoha_metadata_dst_free() runs metadata_dst_free() which frees the
metadata_dst with kfree() immediately, bypassing the RCU grace period.
In the RX path, skb_dst_set_noref() sets a non-refcounted pointer from
the skb to the metadata_dst. This function requires RCU read-side
protection and the dst must remain valid until all RCU readers complete.
Since metadata_dst_free() calls kfree() directly, an use-after-free can
occur if any skb still holds a noref pointer to the dst when the driver
tears it down.
Replace metadata_dst_free() with dst_release() which properly goes
through the refcount path: when the refcount drops to zero, it schedules
the actual free via call_rcu_hurry(), ensuring all RCU readers have
completed before the memory is freed.
Fixes: af3cf757d5c9 ("net: airoha: Move DSA tag in DMA descriptor")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260602-airoha-mtk-metadata-uaf-fix-v1-1-3aaa99d83351@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/airoha/airoha_eth.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c index cecd66251dba..eab6a98d62b9 100644 --- a/drivers/net/ethernet/airoha/airoha_eth.c +++ b/drivers/net/ethernet/airoha/airoha_eth.c @@ -2936,7 +2936,7 @@ static void airoha_metadata_dst_free(struct airoha_gdm_port *port) if (!port->dsa_meta[i]) continue; - metadata_dst_free(port->dsa_meta[i]); + dst_release(&port->dsa_meta[i]->dst); } } |