6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Praveen Kaligineedi <pkaligineedi@xxxxxxxxxx> From: Bailey Forrest <bcf@xxxxxxxxxx> Call skb_shinfo() after gve_prep_tso() on DQO TX path. gve_prep_tso() calls skb_cow_head(), which may reallocate shinfo causing a use after free. This bug was unintentionally fixed by 'a6fb8d5a8b69 ("gve: Tx path for DQO-QPL")' while adding DQO-QPL format support in 6.6. That patch is not appropriate for stable releases. Fixes: a57e5de476be ("gve: DQO: Add TX path") Signed-off-by: Praveen Kaligineedi <pkaligineedi@xxxxxxxxxx> Signed-off-by: Bailey Forrest <bcf@xxxxxxxxxx> Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reviewed-by: Jeroen de Borst <jeroendb@xxxxxxxxxx> Reviewed-by: Kevin DeCabooter <decabooter@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/google/gve/gve_tx_dqo.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c +++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c @@ -350,6 +350,7 @@ static void gve_tx_fill_pkt_desc_dqo(str /* Validates and prepares `skb` for TSO. * * Returns header length, or < 0 if invalid. + * Warning : Might change skb->head (and thus skb_shinfo). */ static int gve_prep_tso(struct sk_buff *skb) { @@ -451,8 +452,8 @@ gve_tx_fill_general_ctx_desc(struct gve_ static int gve_tx_add_skb_no_copy_dqo(struct gve_tx_ring *tx, struct sk_buff *skb) { - const struct skb_shared_info *shinfo = skb_shinfo(skb); const bool is_gso = skb_is_gso(skb); + struct skb_shared_info *shinfo; u32 desc_idx = tx->dqo_tx.tail; struct gve_tx_pending_packet_dqo *pkt; @@ -477,6 +478,8 @@ static int gve_tx_add_skb_no_copy_dqo(st desc_idx = (desc_idx + 1) & tx->mask; } + /* Must get after gve_prep_tso(), which can change shinfo. */ + shinfo = skb_shinfo(skb); gve_tx_fill_general_ctx_desc(&tx->dqo.tx_ring[desc_idx].general_ctx, &metadata); desc_idx = (desc_idx + 1) & tx->mask;