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authorVladimir Oltean2022-03-02 21:39:39 +0200
committerJakub Kicinski2022-03-03 08:01:55 -0800
commit10b6bb62ae1a49ee818fc479cf57b8900176773e (patch)
tree805e60ea72baec1086592d580c33cb6b3ee99b99 /net/dcb
parent8ccffe9ac3239e549beaa0a9d5e1a1eac94e866c (diff)
net: dcb: disable softirqs in dcbnl_flush_dev()
Ido Schimmel points out that since commit 52cff74eef5d ("dcbnl : Disable software interrupts before taking dcb_lock"), the DCB API can be called by drivers from softirq context. One such in-tree example is the chelsio cxgb4 driver: dcb_rpl -> cxgb4_dcb_handle_fw_update -> dcb_ieee_setapp If the firmware for this driver happened to send an event which resulted in a call to dcb_ieee_setapp() at the exact same time as another DCB-enabled interface was unregistering on the same CPU, the softirq would deadlock, because the interrupted process was already holding the dcb_lock in dcbnl_flush_dev(). Fix this unlikely event by using spin_lock_bh() in dcbnl_flush_dev() as in the rest of the dcbnl code. Fixes: 91b0383fef06 ("net: dcb: flush lingering app table entries for unregistered devices") Reported-by: Ido Schimmel <idosch@idosch.org> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Link: https://lore.kernel.org/r/20220302193939.1368823-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/dcb')
-rw-r--r--net/dcb/dcbnl.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 36c91273daac..dc4fb699b56c 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -2077,7 +2077,7 @@ static void dcbnl_flush_dev(struct net_device *dev)
{
struct dcb_app_type *itr, *tmp;
- spin_lock(&dcb_lock);
+ spin_lock_bh(&dcb_lock);
list_for_each_entry_safe(itr, tmp, &dcb_app_list, list) {
if (itr->ifindex == dev->ifindex) {
@@ -2086,7 +2086,7 @@ static void dcbnl_flush_dev(struct net_device *dev)
}
}
- spin_unlock(&dcb_lock);
+ spin_unlock_bh(&dcb_lock);
}
static int dcbnl_netdevice_event(struct notifier_block *nb,