This is a note to let you know that I've just added the patch titled enetc: Fix illegal access when reading affinity_hint to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: enetc-fix-illegal-access-when-reading-affinity_hint.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 660f756a6358ea6c7aa75a240b0ca081b89f140c Author: Claudiu Manoil <claudiu.manoil@xxxxxxx> Date: Fri Sep 17 13:22:05 2021 +0300 enetc: Fix illegal access when reading affinity_hint [ Upstream commit 7237a494decfa17d0b9d0076e6cee3235719de90 ] irq_set_affinity_hit() stores a reference to the cpumask_t parameter in the irq descriptor, and that reference can be accessed later from irq_affinity_hint_proc_show(). Since the cpu_mask parameter passed to irq_set_affinity_hit() has only temporary storage (it's on the stack memory), later accesses to it are illegal. Thus reads from the corresponding procfs affinity_hint file can result in paging request oops. The issue is fixed by the get_cpu_mask() helper, which provides a permanent storage for the cpumask_t parameter. Fixes: d4fd0404c1c9 ("enetc: Introduce basic PF and VF ENETC ethernet drivers") Signed-off-by: Claudiu Manoil <claudiu.manoil@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index 3ca93adb9662..7f90c27c0e79 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -1879,7 +1879,6 @@ static void enetc_clear_bdrs(struct enetc_ndev_priv *priv) static int enetc_setup_irqs(struct enetc_ndev_priv *priv) { struct pci_dev *pdev = priv->si->pdev; - cpumask_t cpu_mask; int i, j, err; for (i = 0; i < priv->bdr_int_num; i++) { @@ -1908,9 +1907,7 @@ static int enetc_setup_irqs(struct enetc_ndev_priv *priv) enetc_wr(hw, ENETC_SIMSITRV(idx), entry); } - cpumask_clear(&cpu_mask); - cpumask_set_cpu(i % num_online_cpus(), &cpu_mask); - irq_set_affinity_hint(irq, &cpu_mask); + irq_set_affinity_hint(irq, get_cpu_mask(i % num_online_cpus())); } return 0;