From: Julia Lawall <julia.law...@lip6.fr> This makes two changes. In ath6kl_wmi_cmd_send, a call to dev_kfree_skb on the skb argument is added to the initial sanity check to more completely establish the invariant that ath6kl_wmi_cmd_send owns its skb argument. Then, in ath6kl_wmi_sync_point, on failure of the call to ath6kl_wmi_cmd_send, the clearing of the local skb variable is moved up, so that the error-handling code at the end of the function does not free it again.
A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r@ identifier f,free,a; parameter list[n] ps; type T; expression e; @@ f(ps,T a,...) { ... when any when != a = e if(...) { ... free(a); ... return ...; } ... when any } @@ identifier r.f,r.free; expression x,a; expression list[r.n] xs; @@ * x = f(xs,a,...); if (...) { ... free(a); ... return ...; } // </smpl> Signed-off-by: Julia Lawall <julia.law...@lip6.fr> --- Not tested. drivers/net/wireless/ath/ath6kl/wmi.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c index c30ab4b..50f50e4 100644 --- a/drivers/net/wireless/ath/ath6kl/wmi.c +++ b/drivers/net/wireless/ath/ath6kl/wmi.c @@ -1677,8 +1677,10 @@ int ath6kl_wmi_cmd_send(struct wmi *wmi, u8 if_idx, struct sk_buff *skb, int ret; u16 info1; - if (WARN_ON(skb == NULL || (if_idx > (wmi->parent_dev->vif_max - 1)))) + if (WARN_ON(skb == NULL || if_idx > (wmi->parent_dev->vif_max - 1))) { + dev_kfree_skb(skb); return -EINVAL; + } ath6kl_dbg(ATH6KL_DBG_WMI, "wmi tx id %d len %d flag %d\n", cmd_id, skb->len, sync_flag); @@ -2348,12 +2350,12 @@ static int ath6kl_wmi_sync_point(struct wmi *wmi, u8 if_idx) ret = ath6kl_wmi_cmd_send(wmi, if_idx, skb, WMI_SYNCHRONIZE_CMDID, NO_SYNC_WMIFLAG); - if (ret) - goto free_skb; - /* cmd buffer sent, we no longer own it */ skb = NULL; + if (ret) + goto free_skb; + for (index = 0; index < num_pri_streams; index++) { if (WARN_ON(!data_sync_bufs[index].skb)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
