From: Zekun Shen bruceshenzk@gmail.com
[ Upstream commit e89df5c4322c1bf495f62d74745895b5fd2a4393 ]
There is a race condition exist during termination. The path is alx_stop and then alx_remove. An alx_schedule_link_check could be called before alx_stop by interrupt handler and invoke alx_link_check later. Alx_stop frees the napis, and alx_remove cancels any pending works. If any of the work is scheduled before termination and invoked before alx_remove, a null-ptr-deref occurs because both expect alx->napis[i].
This patch fix the race condition by moving cancel_work_sync functions before alx_free_napis inside alx_stop. Because interrupt handler can call alx_schedule_link_check again, alx_free_irq is moved before cancel_work_sync calls too.
Signed-off-by: Zekun Shen bruceshenzk@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/atheros/alx/main.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c index 6d32211349275..dd63b993ce7b3 100644 --- a/drivers/net/ethernet/atheros/alx/main.c +++ b/drivers/net/ethernet/atheros/alx/main.c @@ -1250,8 +1250,12 @@ static int __alx_open(struct alx_priv *alx, bool resume)
static void __alx_stop(struct alx_priv *alx) { - alx_halt(alx); alx_free_irq(alx); + + cancel_work_sync(&alx->link_check_wk); + cancel_work_sync(&alx->reset_wk); + + alx_halt(alx); alx_free_rings(alx); alx_free_napis(alx); } @@ -1861,9 +1865,6 @@ static void alx_remove(struct pci_dev *pdev) struct alx_priv *alx = pci_get_drvdata(pdev); struct alx_hw *hw = &alx->hw;
- cancel_work_sync(&alx->link_check_wk); - cancel_work_sync(&alx->reset_wk); - /* restore permanent mac address */ alx_set_macaddr(hw, hw->perm_addr);