[PATCH 6.19 155/220] net: usb: aqc111: Do not perform PM inside suspend callback

Greg Kroah-Hartman
2026-03-23T13:57:26Z

From: Nikola Z. Ivanov <zlatistiv@gmail.com>

[ Upstream commit 069c8f5aebe4d5224cf62acc7d4b3486091c658a ]

syzbot reports "task hung in rpm_resume"

This is caused by aqc111_suspend calling
the PM variant of its write_cmd routine.

The simplified call trace looks like this:

rpm_suspend()
usb_suspend_both() - here udev->dev.power.runtime_status == RPM_SUSPENDING
aqc111_suspend() - called for the usb device interface
aqc111_write32_cmd()
usb_autopm_get_interface()
pm_runtime_resume_and_get()
rpm_resume() - here we call rpm_resume() on our parent
rpm_resume() - Here we wait for a status change that will never happen.

At this point we block another task which holds
rtnl_lock and locks up the whole networking stack.

Fix this by replacing the write_cmd calls with their _nopm variants

Reported-by: syzbot+48dc1e8dfc92faf1124c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=48dc1e8dfc92faf1124c
Fixes: e58ba4544c77 ("net: usb: aqc111: Add support for wake on LAN by MAGIC packet")
Signed-off-by: Nikola Z. Ivanov <zlatistiv@gmail.com>
Link: https://patch.msgid.link/20260313141643.1181386-1-zlatistiv@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/usb/aqc111.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/usb/aqc111.c b/drivers/net/usb/aqc111.c
index 9201ee10a13f7..d316aa66dbc23 100644
--- a/drivers/net/usb/aqc111.c
+++ b/drivers/net/usb/aqc111.c
@@ -1400,14 +1400,14 @@ static int aqc111_suspend(struct usb_interface *intf, pm_message_t message)
aqc111_write16_cmd_nopm(dev, AQ_ACCESS_MAC,
SFR_MEDIUM_STATUS_MODE, 2, &reg16);

- aqc111_write_cmd(dev, AQ_WOL_CFG, 0, 0,
- WOL_CFG_SIZE, &wol_cfg);
- aqc111_write32_cmd(dev, AQ_PHY_OPS, 0, 0,
- &aqc111_data->phy_cfg);
+ aqc111_write_cmd_nopm(dev, AQ_WOL_CFG, 0, 0,
+ WOL_CFG_SIZE, &wol_cfg);
+ aqc111_write32_cmd_nopm(dev, AQ_PHY_OPS, 0, 0,
+ &aqc111_data->phy_cfg);
} else {
aqc111_data->phy_cfg |= AQ_LOW_POWER;
- aqc111_write32_cmd(dev, AQ_PHY_OPS, 0, 0,
- &aqc111_data->phy_cfg);
+ aqc111_write32_cmd_nopm(dev, AQ_PHY_OPS, 0, 0,
+ &aqc111_data->phy_cfg);

/* Disable RX path */
aqc111_read16_cmd_nopm(dev, AQ_ACCESS_MAC,
--
2.51.0