]> git.ipfire.org Git - thirdparty/kernel/linux.git/commit
usb: typec: ucsi: ccg: Fix use-after-free of ucsi on remove
authorFan Wu <fanwu01@zju.edu.cn>
Tue, 16 Jun 2026 13:20:11 +0000 (13:20 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 Jun 2026 14:23:05 +0000 (15:23 +0100)
commit1f0bdc2884b67de337215079bba166df0cdf4ac5
tree3ed5917bc14b79e2ace1963f7fbf36f13c1f3dcd
parent7b681dd5fbf60b24a13c14661e5b7735759fb491
usb: typec: ucsi: ccg: Fix use-after-free of ucsi on remove

The threaded IRQ handler ccg_irq_handler() calls ucsi_notify_common(),
which on a connector-change event calls ucsi_connector_change() and
schedules connector work.  In ucsi_ccg_remove(), ucsi_destroy() frees
uc->ucsi (kfree) before free_irq() is called, so a handler invocation
already in flight may access the freed object after ucsi_destroy().

  CPU 0 (remove)            | CPU 1 (threaded IRQ)
    ucsi_destroy(uc->ucsi)  |   ccg_irq_handler()
      kfree(ucsi) // FREE   |     ucsi_notify_common(uc->ucsi) // USE

Move free_irq() before ucsi_destroy() in the remove path.  It is kept
after ucsi_unregister(): ucsi_unregister() cancels connector work whose
handler issues GET_CONNECTOR_STATUS through ucsi_send_command_common(),
which waits for a completion that is signalled from the IRQ handler, so
the IRQ must stay active until that work has been cancelled.

The probe error path already orders free_irq() before ucsi_destroy().

This bug was found by static analysis.

Fixes: e32fd989ac1c ("usb: typec: ucsi: ccg: Move to the new API")
Cc: stable <stable@kernel.org>
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://patch.msgid.link/20260616132011.103279-1-fanwu01@zju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/typec/ucsi/ucsi_ccg.c