6.6-stable review patch. If anyone has any objections, please let me know.
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From: Lizhi Xu lizhi.xu@windriver.com
[ Upstream commit 09bf21bf5249880f62fe759b53b14b4b52900c6c ]
Interrupts are disabled before entering usb_hcd_giveback_urb(). A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be acquired with disabled interrupts.
Save the interrupt status and restore it after usb_hcd_giveback_urb().
syz reported: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 rt_spin_lock+0xc7/0x2c0 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:44 [inline] mon_bus_complete drivers/usb/mon/mon_main.c:134 [inline] mon_complete+0x5c/0x200 drivers/usb/mon/mon_main.c:147 usbmon_urb_complete include/linux/usb/hcd.h:738 [inline] __usb_hcd_giveback_urb+0x254/0x5e0 drivers/usb/core/hcd.c:1647 vhci_urb_enqueue+0xb4f/0xe70 drivers/usb/usbip/vhci_hcd.c:818
Reported-by: syzbot+205ef33a3b636b4181fb@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=205ef33a3b636b4181fb Signed-off-by: Lizhi Xu lizhi.xu@windriver.com Acked-by: Shuah Khan skhan@linuxfoundation.org Link: https://lore.kernel.org/r/20250916014143.1439759-1-lizhi.xu@windriver.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/usbip/vhci_hcd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c index b22e0881bfaf..0bc4805cfa3e 100644 --- a/drivers/usb/usbip/vhci_hcd.c +++ b/drivers/usb/usbip/vhci_hcd.c @@ -830,15 +830,15 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag no_need_xmit: usb_hcd_unlink_urb_from_ep(hcd, urb); no_need_unlink: - spin_unlock_irqrestore(&vhci->lock, flags); if (!ret) { /* usb_hcd_giveback_urb() should be called with * irqs disabled */ - local_irq_disable(); + spin_unlock(&vhci->lock); usb_hcd_giveback_urb(hcd, urb, urb->status); - local_irq_enable(); + spin_lock(&vhci->lock); } + spin_unlock_irqrestore(&vhci->lock, flags); return ret; }