Commit aed0fd4a authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville

iwlagn: fix NULL ptr deref when reprogramming sta w/o LQ

Reinette reports a crash in iwl_reprogram_ap_sta(). The
debugging shows:

  b1 16    mov    $0x16,%cl
 *f3 a5    rep movsl %ds     <-- trapping instruction:(%rsi),%es:(%rdi)

which is a memcpy of 22 (0x16) words (movsl). this points
to "priv->stations[sta_id].lq" being NULL since that is
the memcpy() of that size here.

The only way I see for this to happen is if we try to
do some RXON reprogramming while connecting to an AP,
after tx_sync() but before full setup, but that seems
like something that might very well happen.

Fix this by checking if the LQ is present and only then
reprogramming it.
Reported-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent b2ccccdc
......@@ -647,7 +647,7 @@ void iwl_reprogram_ap_sta(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
int ret;
struct iwl_addsta_cmd sta_cmd;
struct iwl_link_quality_cmd lq;
bool active;
bool active, have_lq = false;
spin_lock_irqsave(&priv->shrd->sta_lock, flags);
if (!(priv->stations[sta_id].used & IWL_STA_DRIVER_ACTIVE)) {
......@@ -657,7 +657,10 @@ void iwl_reprogram_ap_sta(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
memcpy(&sta_cmd, &priv->stations[sta_id].sta, sizeof(sta_cmd));
sta_cmd.mode = 0;
memcpy(&lq, priv->stations[sta_id].lq, sizeof(lq));
if (priv->stations[sta_id].lq) {
memcpy(&lq, priv->stations[sta_id].lq, sizeof(lq));
have_lq = true;
}
active = priv->stations[sta_id].used & IWL_STA_UCODE_ACTIVE;
priv->stations[sta_id].used &= ~IWL_STA_DRIVER_ACTIVE;
......@@ -679,7 +682,8 @@ void iwl_reprogram_ap_sta(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
if (ret)
IWL_ERR(priv, "failed to re-add STA %pM (%d)\n",
priv->stations[sta_id].sta.sta.addr, ret);
iwl_send_lq_cmd(priv, ctx, &lq, CMD_SYNC, true);
if (have_lq)
iwl_send_lq_cmd(priv, ctx, &lq, CMD_SYNC, true);
}
int iwl_get_free_ucode_key_offset(struct iwl_priv *priv)
......
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