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 5.4-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-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e0bc1ec9e376400a721dd74afd2382d08e69886d
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 b77eaf31bd4e..cee77326e7e8 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -1222,7 +1222,6 @@ 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++) {
@@ -1249,9 +1248,7 @@ 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;
