From: Claudiu Manoil Date: Fri, 17 Sep 2021 10:22:05 +0000 (+0300) Subject: enetc: Fix illegal access when reading affinity_hint X-Git-Tag: xarray-5.18~961^2~30 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7237a494decfa17d0b9d0076e6cee3235719de90;p=users%2Fwilly%2Fxarray.git enetc: Fix illegal access when reading affinity_hint 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 Signed-off-by: David S. Miller --- 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;