Messages in this thread Patch in this message | | | Date | Wed, 21 Mar 2012 14:15:40 -0700 | From | Greg KH <> | Subject | [ 8/9] iwl3945: fix possible il->txq NULL pointer dereference in delayed works |
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3.2-stable review patch. If anyone has any objections, please let me know.
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From: Stanislaw Gruszka <sgruszka@redhat.com>
commit 210787e82a0ac1ffb5d7be1c796f0c51050849ad upstream.
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 <linuxhippy@gmail.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
--- drivers/net/wireless/iwlegacy/iwl-3945.c | 7 ++++--- drivers/net/wireless/iwlegacy/iwl3945-base.c | 2 +- 2 files changed, 5 insertions(+), 4 deletions(-)
--- a/drivers/net/wireless/iwlegacy/iwl-3945.c +++ b/drivers/net/wireless/iwlegacy/iwl-3945.c @@ -1870,11 +1870,12 @@ static void iwl3945_bg_reg_txpower_perio struct iwl_priv *priv = container_of(work, struct iwl_priv, _3945.thermal_periodic.work); - if (test_bit(STATUS_EXIT_PENDING, &priv->status)) - return; - mutex_lock(&priv->mutex); + if (test_bit(STATUS_EXIT_PENDING, &priv->status) || priv->txq == NULL) + goto out; + iwl3945_reg_txpower_periodic(priv); +out: mutex_unlock(&priv->mutex); } --- a/drivers/net/wireless/iwlegacy/iwl3945-base.c +++ b/drivers/net/wireless/iwlegacy/iwl3945-base.c @@ -2513,7 +2513,7 @@ static void iwl3945_bg_alive_start(struc container_of(data, struct iwl_priv, alive_start.work); mutex_lock(&priv->mutex); - if (test_bit(STATUS_EXIT_PENDING, &priv->status)) + if (test_bit(STATUS_EXIT_PENDING, &priv->status) || priv->txq == NULL) goto out; iwl3945_alive_start(priv);
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