[PATCH RESEND] net/cisco: Fix a sleep-in-atomic-context bug in enic_init_affinity_hint()

From: Kaige Li
Date: Mon Jun 22 2020 - 09:11:28 EST


The kernel module may sleep with holding a spinlock.

The function call paths (from bottom to top) are:

[FUNC] zalloc_cpumask_var(GFP_KERNEL)
drivers/net/ethernet/cisco/enic/enic_main.c, 125: zalloc_cpumask_var in enic_init_affinity_hint
drivers/net/ethernet/cisco/enic/enic_main.c, 1918: enic_init_affinity_hint in enic_open
drivers/net/ethernet/cisco/enic/enic_main.c, 2348: enic_open in enic_reset
drivers/net/ethernet/cisco/enic/enic_main.c, 2341: spin_lock in enic_reset

To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC.

Signed-off-by: Kaige Li <likaige@xxxxxxxxxxx>
---
drivers/net/ethernet/cisco/enic/enic_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index cd5fe4f..ee62065 100644
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/drivers/net/ethernet/cisco/enic/enic_main.c
@@ -122,7 +122,7 @@ static void enic_init_affinity_hint(struct enic *enic)
!cpumask_empty(enic->msix[i].affinity_mask)))
continue;
if (zalloc_cpumask_var(&enic->msix[i].affinity_mask,
- GFP_KERNEL))
+ GFP_ATOMIC))
cpumask_set_cpu(cpumask_local_spread(i, numa_node),
enic->msix[i].affinity_mask);
}
--
2.1.0