diff options
| author | Radu Rendec <rrendec@redhat.com> | 2024-07-02 17:08:37 -0400 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-07-03 19:15:22 -0700 |
| commit | 9a0c28efeec6383ef22e97437616b920e7320b67 (patch) | |
| tree | 5a43b410224539eaffecec465e23b04312a30f5f /drivers | |
| parent | 8eb301bd7b0f45d36e663ecbe59b7c80b9863950 (diff) | |
net: rswitch: Avoid use-after-free in rswitch_poll()
The use-after-free is actually in rswitch_tx_free(), which is inlined in
rswitch_poll(). Since `skb` and `gq->skbs[gq->dirty]` are in fact the
same pointer, the skb is first freed using dev_kfree_skb_any(), then the
value in skb->len is used to update the interface statistics.
Let's move around the instructions to use skb->len before the skb is
freed.
This bug is trivial to reproduce using KFENCE. It will trigger a splat
every few packets. A simple ARP request or ICMP echo request is enough.
Fixes: 271e015b9153 ("net: rswitch: Add unmap_addrs instead of dma address in each desc")
Signed-off-by: Radu Rendec <rrendec@redhat.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://patch.msgid.link/20240702210838.2703228-1-rrendec@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/renesas/rswitch.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/ethernet/renesas/rswitch.c b/drivers/net/ethernet/renesas/rswitch.c index dcab638c57fe..24c90d8f5a44 100644 --- a/drivers/net/ethernet/renesas/rswitch.c +++ b/drivers/net/ethernet/renesas/rswitch.c @@ -871,13 +871,13 @@ static void rswitch_tx_free(struct net_device *ndev) dma_rmb(); skb = gq->skbs[gq->dirty]; if (skb) { + rdev->ndev->stats.tx_packets++; + rdev->ndev->stats.tx_bytes += skb->len; dma_unmap_single(ndev->dev.parent, gq->unmap_addrs[gq->dirty], skb->len, DMA_TO_DEVICE); dev_kfree_skb_any(gq->skbs[gq->dirty]); gq->skbs[gq->dirty] = NULL; - rdev->ndev->stats.tx_packets++; - rdev->ndev->stats.tx_bytes += skb->len; } desc->desc.die_dt = DT_EEMPTY; } |