This is a note to let you know that I've just added the patch titled
ethernet: rocker: fix sleep in atomic context bug in neigh_timer_handler
to the 4.19-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:
ethernet-rocker-fix-sleep-in-atomic-context-bug-in-n.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b9181c6697e0191a94ad02def1ea54507fe2e56c
Author: Duoming Zhou <duoming@xxxxxxxxxx>
Date: Sat Aug 27 23:38:15 2022 +0800
ethernet: rocker: fix sleep in atomic context bug in neigh_timer_handler
[ Upstream commit c0955bf957be4bead01fae1d791476260da7325d ]
The function neigh_timer_handler() is a timer handler that runs in an
atomic context. When used by rocker, neigh_timer_handler() calls
"kzalloc(.., GFP_KERNEL)" that may sleep. As a result, the sleep in
atomic context bug will happen. One of the processes is shown below:
ofdpa_fib4_add()
...
neigh_add_timer()
(wait a timer)
neigh_timer_handler()
neigh_release()
neigh_destroy()
rocker_port_neigh_destroy()
rocker_world_port_neigh_destroy()
ofdpa_port_neigh_destroy()
ofdpa_port_ipv4_neigh()
kzalloc(sizeof(.., GFP_KERNEL) //may sleep
This patch changes the gfp_t parameter of kzalloc() from GFP_KERNEL to
GFP_ATOMIC in order to mitigate the bug.
Fixes: 00fc0c51e35b ("rocker: Change world_ops API and implementation to be switchdev independant")
Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/rocker/rocker_ofdpa.c b/drivers/net/ethernet/rocker/rocker_ofdpa.c
index 6473cc68c2d5c..4039e1fc6e92a 100644
--- a/drivers/net/ethernet/rocker/rocker_ofdpa.c
+++ b/drivers/net/ethernet/rocker/rocker_ofdpa.c
@@ -1276,7 +1276,7 @@ static int ofdpa_port_ipv4_neigh(struct ofdpa_port *ofdpa_port,
bool removing;
int err = 0;
- entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
if (!entry)
return -ENOMEM;
