From 210787e82a0ac1ffb5d7be1c796f0c51050849ad Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Thu, 8 Mar 2012 13:16:01 +0100 Subject: [PATCH] iwl3945: fix possible il->txq NULL pointer dereference in delayed works On il3945_down procedure we free tx queue data and nullify il->txq pointer. After that we drop mutex and then cancel delayed works. There is possibility, that after drooping mutex and before the cancel, some delayed work will start and crash while trying to send commands to the device. For example, here is reported crash in il3945_bg_reg_txpower_periodic(): https://bugzilla.kernel.org/show_bug.cgi?id=42766#c10 Patch fix problem by adding il->txq check on works that send commands, hence utilize tx queue. Reported-by: Clemens Eisserer Cc: stable@vger.kernel.org Signed-off-by: Stanislaw Gruszka Signed-off-by: John W. Linville --- drivers/net/wireless/iwlegacy/3945-mac.c | 2 +- drivers/net/wireless/iwlegacy/3945.c | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/iwlegacy/3945-mac.c b/drivers/net/wireless/iwlegacy/3945-mac.c index 54b2d39..a7dfba8 100644 --- a/drivers/net/wireless/iwlegacy/3945-mac.c +++ b/drivers/net/wireless/iwlegacy/3945-mac.c @@ -2475,7 +2475,7 @@ il3945_bg_alive_start(struct work_struct *data) container_of(data, struct il_priv, alive_start.work); mutex_lock(&il->mutex); - if (test_bit(S_EXIT_PENDING, &il->status)) + if (test_bit(S_EXIT_PENDING, &il->status) || il->txq == NULL) goto out; il3945_alive_start(il); diff --git a/drivers/net/wireless/iwlegacy/3945.c b/drivers/net/wireless/iwlegacy/3945.c index 1489b15..c80eb9b 100644 --- a/drivers/net/wireless/iwlegacy/3945.c +++ b/drivers/net/wireless/iwlegacy/3945.c @@ -1870,11 +1870,12 @@ il3945_bg_reg_txpower_periodic(struct work_struct *work) struct il_priv *il = container_of(work, struct il_priv, _3945.thermal_periodic.work); - if (test_bit(S_EXIT_PENDING, &il->status)) - return; - mutex_lock(&il->mutex); + if (test_bit(S_EXIT_PENDING, &il->status) || il->txq == NULL) + goto out; + il3945_reg_txpower_periodic(il); +out: mutex_unlock(&il->mutex); } -- 2.7.4