From: Eric Dumazet <edumazet@google.com> mainline inclusion from mainline-v7.2-rc1 commit d09a78a2a469e4fab75108325efb813c49520809 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/17648 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Marek Szyprowski reported a deadlock during system resume when virtio_net driver is used. The deadlock occurs because netif_device_attach() is called while holding dev->tx_global_lock (via netif_tx_lock_bh() in virtnet_restore_up()). netif_device_attach() calls __netdev_watchdog_up(), which now also tries to acquire dev->tx_global_lock to synchronize with dev_watchdog(). This recursive lock acquisition results in a deadlock. Fix this by removing the tx_global_lock acquisition from netdev_watchdog_up(). The critical state (watchdog_timer and watchdog_ref_held) is already protected by dev->watchdog_lock, which was introduced in the blamed commit. Fixes: 8eed5519e496 ("net: watchdog: fix refcount tracking races") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Closes: https://lore.kernel.org/netdev/a443376e-5187-4268-93b3-58047ef113a8@samsung.... Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260622110108.69541-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: JiangJieHua <jiangjiehua1@huawei.com> --- net/sched/sch_generic.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 6b0125206c048..20abe6bf7faf9 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -567,9 +567,8 @@ void netdev_watchdog_up(struct net_device *dev) return; if (dev->watchdog_timeo <= 0) dev->watchdog_timeo = 5*HZ; - spin_lock_bh(&dev->tx_global_lock); - spin_lock(&dev->watchdog_lock); + spin_lock_bh(&dev->watchdog_lock); if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) { if (!dev->watchdog_ref_held) { @@ -578,9 +577,7 @@ void netdev_watchdog_up(struct net_device *dev) dev->watchdog_ref_held = true; } } - spin_unlock(&dev->watchdog_lock); - - spin_unlock_bh(&dev->tx_global_lock); + spin_unlock_bh(&dev->watchdog_lock); } EXPORT_SYMBOL_GPL(netdev_watchdog_up); -- 2.33.8