From a2f054c10bef0b54600ec9cb776508443e941343 Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Mon, 10 Jul 2023 13:41:27 -0700 Subject: [PATCH] iavf: fix potential deadlock on allocation failure In iavf_adminq_task(), if kzalloc() fails to allocate the event.msg_buf, the function will exit without releasing the adapter->crit_lock. This is unlikely, but if it happens, the next access to that mutex will deadlock. Fix this by moving the unlock to the end of the function, and adding a new label to allow jumping to the unlock portion of the function exit flow. Fixes: fc2e6b3b132a ("iavf: Rework mutexes for better synchronisation") Signed-off-by: Jacob Keller Tested-by: Rafal Romanowski Signed-off-by: Tony Nguyen --- drivers/net/ethernet/intel/iavf/iavf_main.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c index 3a88d41..939c8126 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_main.c +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c @@ -3264,7 +3264,7 @@ static void iavf_adminq_task(struct work_struct *work) event.buf_len = IAVF_MAX_AQ_BUF_SIZE; event.msg_buf = kzalloc(event.buf_len, GFP_KERNEL); if (!event.msg_buf) - goto out; + goto unlock; do { ret = iavf_clean_arq_element(hw, &event, &pending); @@ -3279,7 +3279,6 @@ static void iavf_adminq_task(struct work_struct *work) if (pending != 0) memset(event.msg_buf, 0, IAVF_MAX_AQ_BUF_SIZE); } while (pending); - mutex_unlock(&adapter->crit_lock); if (iavf_is_reset_in_progress(adapter)) goto freedom; @@ -3323,6 +3322,8 @@ static void iavf_adminq_task(struct work_struct *work) freedom: kfree(event.msg_buf); +unlock: + mutex_unlock(&adapter->crit_lock); out: /* re-enable Admin queue interrupt cause */ iavf_misc_irq_enable(adapter); -- 2.7.4