can: mcp251x: fix deadlock in error path of mcp251x_open

[ Upstream commit ab3f894de2 ]

The mcp251x_open() function call free_irq() in its error path with the
mpc_lock mutex held. But if an interrupt already occurred the
interrupt handler will be waiting for the mpc_lock and free_irq() will
deadlock waiting for the handler to finish.

This issue is similar to the one fixed in commit 7dd9c26bd6 ("can:
mcp251x: fix deadlock if an interrupt occurs during mcp251x_open") but
for the error path.

To solve this issue move the call to free_irq() after the lock is
released. Setting `priv->force_quit = 1` beforehand ensure that the IRQ
handler will exit right away once it acquired the lock.

Signed-off-by: Alban Bedel <alban.bedel@lht.dlh.de>
Link: https://patch.msgid.link/20260209144706.2261954-1-alban.bedel@lht.dlh.de
Fixes: bf66f3736a ("can: mcp251x: Move to threaded interrupts instead of workqueues.")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Alban Bedel 2026-02-09 15:47:05 +01:00 • committed by Sasha Levin
commit d27f12c3f5