diff options
| author | Lorenzo Bianconi <lorenzo@kernel.org> | 2026-06-02 11:21:05 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-03 19:15:32 -0700 |
| commit | 80df409e1a483676826a6c66e693dba6ac507751 (patch) | |
| tree | c407a812995141d8817a12eec0b7fa2419209a7f /drivers | |
| parent | b38cae85d1c45ff189d7ecb6ac36f41cdc3d84d0 (diff) | |
net: ethernet: mtk_eth_soc: Fix use-after-free in metadata dst teardown
mtk_free_dev() calls 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, a 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: 2d7605a72906 ("net: ethernet: mtk_eth_soc: enable hardware DSA untagging")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260602-airoha-mtk-metadata-uaf-fix-v1-2-3aaa99d83351@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/mediatek/mtk_eth_soc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c index 8d225bc9f063..7d771168b990 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -4491,7 +4491,7 @@ static int mtk_free_dev(struct mtk_eth *eth) for (i = 0; i < ARRAY_SIZE(eth->dsa_meta); i++) { if (!eth->dsa_meta[i]) break; - metadata_dst_free(eth->dsa_meta[i]); + dst_release(ð->dsa_meta[i]->dst); } return 0; |