From: Shengjiu Wang shengjiu.wang@nxp.com
commit 467233a4ac29b215d492843d067a9f091e6bf0c5 upstream.
The rpmsg_dev_remove() in rpmsg_core is the place for releasing this default endpoint.
So need to avoid destroying the default endpoint in rpmsg_chrdev_eptdev_destroy(), this should be the same as rpmsg_eptdev_release(). Otherwise there will be double destroy issue that ept->refcount report warning:
refcount_t: underflow; use-after-free.
Call trace: refcount_warn_saturate+0xf8/0x150 virtio_rpmsg_destroy_ept+0xd4/0xec rpmsg_dev_remove+0x60/0x70
The issue can be reproduced by stopping remoteproc before closing the /dev/rpmsgX.
Fixes: bea9b79c2d10 ("rpmsg: char: Add possibility to use default endpoint of the rpmsg device") Signed-off-by: Shengjiu Wang shengjiu.wang@nxp.com Reviewed-by: Arnaud Pouliquen arnaud.pouliquen@foss.st.com Reviewed-by: Peng Fan peng.fan@nxp.com Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/1663725523-6514-1-git-send-email-shengjiu.wang@nxp... Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/rpmsg/rpmsg_char.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -76,7 +76,9 @@ int rpmsg_chrdev_eptdev_destroy(struct d
mutex_lock(&eptdev->ept_lock); if (eptdev->ept) { - rpmsg_destroy_ept(eptdev->ept); + /* The default endpoint is released by the rpmsg core */ + if (!eptdev->default_ept) + rpmsg_destroy_ept(eptdev->ept); eptdev->ept = NULL; } mutex_unlock(&eptdev->ept_lock);