| Message ID | 20211025163739.v2.2.I507c5cea0cf97db4cedfa0e47029e711e7edd0df@changeid (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix two kernel warnings in glink driver | expand |
On Mon, Oct 25, 2021 at 04:37:54PM -0700, Sujit Kautkar wrote: > Replace cdev add/del APIs with cdev_device_add/cdev_device_del to avoid > below kernel warning. This correctly takes a reference to the parent > device so the parent will not get released until all references to the > cdev are released. > > | ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x7c > | WARNING: CPU: 7 PID: 19892 at lib/debugobjects.c:488 debug_print_object+0x13c/0x1b0 > | CPU: 7 PID: 19892 Comm: kworker/7:4 Tainted: G W 5.4.147-lockdep #1 > | ================================================================== > | Hardware name: Google CoachZ (rev1 - 2) with LTE (DT) > | Workqueue: events kobject_delayed_cleanup > | pstate: 60c00009 (nZCv daif +PAN +UAO) > | pc : debug_print_object+0x13c/0x1b0 > | lr : debug_print_object+0x13c/0x1b0 > | sp : ffffff83b2ec7970 > | x29: ffffff83b2ec7970 x28: dfffffd000000000 > | x27: ffffff83d674f000 x26: dfffffd000000000 > | x25: ffffffd06b8fa660 x24: dfffffd000000000 > | x23: 0000000000000000 x22: ffffffd06b7c5108 > | x21: ffffffd06d597860 x20: ffffffd06e2c21c0 > | x19: ffffffd06d5974c0 x18: 000000000001dad8 > | x17: 0000000000000000 x16: dfffffd000000000 > | BUG: KASAN: use-after-free in qcom_glink_rpdev_release+0x54/0x70 > | x15: ffffffffffffffff x14: 79616c6564203a74 > | x13: 0000000000000000 x12: 0000000000000080 > | Write of size 8 at addr ffffff83d95768d0 by task kworker/3:1/150 > | x11: 0000000000000001 x10: 0000000000000000 > | x9 : fc9e8edec0ad0300 x8 : fc9e8edec0ad0300 > | > | x7 : 0000000000000000 x6 : 0000000000000000 > | x5 : 0000000000000080 x4 : 0000000000000000 > | CPU: 3 PID: 150 Comm: kworker/3:1 Tainted: G W 5.4.147-lockdep #1 > | x3 : ffffffd06c149574 x2 : ffffff83f77f7498 > | x1 : ffffffd06d596f60 x0 : 0000000000000061 > | Hardware name: Google CoachZ (rev1 - 2) with LTE (DT) > | Call trace: > | debug_print_object+0x13c/0x1b0 > | Workqueue: events kobject_delayed_cleanup > | __debug_check_no_obj_freed+0x25c/0x3c0 > | debug_check_no_obj_freed+0x18/0x20 > | Call trace: > | slab_free_freelist_hook+0xb4/0x1bc > | kfree+0xe8/0x2d8 > | dump_backtrace+0x0/0x27c > | rpmsg_ctrldev_release_device+0x78/0xb8 > | device_release+0x68/0x14c > | show_stack+0x20/0x2c > | kobject_cleanup+0x12c/0x298 > | kobject_delayed_cleanup+0x10/0x18 > | dump_stack+0xe0/0x19c > | process_one_work+0x578/0x92c > | worker_thread+0x804/0xcf8 > | print_address_description+0x3c/0x4a8 > | kthread+0x2a8/0x314 > | ret_from_fork+0x10/0x18 > | __kasan_report+0x100/0x124 > > Signed-off-by: Sujit Kautkar <sujitka@chromium.org> > --- > > (no changes since v1) > > drivers/rpmsg/rpmsg_char.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c > index 876ce43df732b..b63a5c396da57 100644 > --- a/drivers/rpmsg/rpmsg_char.c > +++ b/drivers/rpmsg/rpmsg_char.c > @@ -458,7 +458,7 @@ static void rpmsg_ctrldev_release_device(struct device *dev) > > ida_simple_remove(&rpmsg_ctrl_ida, dev->id); > ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); > - cdev_del(&ctrldev->cdev); > + cdev_device_del(&ctrldev->cdev, &ctrldev->dev); > kfree(ctrldev); > } > > @@ -493,14 +493,13 @@ static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev) > dev->id = ret; > dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret); > > - ret = cdev_add(&ctrldev->cdev, dev->devt, 1); > + ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev); > if (ret) > goto free_ctrl_ida; > > /* We can now rely on the release function for cleanup */ > dev->release = rpmsg_ctrldev_release_device; > > - ret = device_add(dev); > if (ret) { > dev_err(&rpdev->dev, "device_add failed: %d\n", ret); > put_device(dev); Also remove the error check? There is already a check above for the status of 'cdev_device_add'.
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c index 876ce43df732b..b63a5c396da57 100644 --- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -458,7 +458,7 @@ static void rpmsg_ctrldev_release_device(struct device *dev) ida_simple_remove(&rpmsg_ctrl_ida, dev->id); ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); - cdev_del(&ctrldev->cdev); + cdev_device_del(&ctrldev->cdev, &ctrldev->dev); kfree(ctrldev); } @@ -493,14 +493,13 @@ static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev) dev->id = ret; dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret); - ret = cdev_add(&ctrldev->cdev, dev->devt, 1); + ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev); if (ret) goto free_ctrl_ida; /* We can now rely on the release function for cleanup */ dev->release = rpmsg_ctrldev_release_device; - ret = device_add(dev); if (ret) { dev_err(&rpdev->dev, "device_add failed: %d\n", ret); put_device(dev);
Replace cdev add/del APIs with cdev_device_add/cdev_device_del to avoid below kernel warning. This correctly takes a reference to the parent device so the parent will not get released until all references to the cdev are released. | ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x7c | WARNING: CPU: 7 PID: 19892 at lib/debugobjects.c:488 debug_print_object+0x13c/0x1b0 | CPU: 7 PID: 19892 Comm: kworker/7:4 Tainted: G W 5.4.147-lockdep #1 | ================================================================== | Hardware name: Google CoachZ (rev1 - 2) with LTE (DT) | Workqueue: events kobject_delayed_cleanup | pstate: 60c00009 (nZCv daif +PAN +UAO) | pc : debug_print_object+0x13c/0x1b0 | lr : debug_print_object+0x13c/0x1b0 | sp : ffffff83b2ec7970 | x29: ffffff83b2ec7970 x28: dfffffd000000000 | x27: ffffff83d674f000 x26: dfffffd000000000 | x25: ffffffd06b8fa660 x24: dfffffd000000000 | x23: 0000000000000000 x22: ffffffd06b7c5108 | x21: ffffffd06d597860 x20: ffffffd06e2c21c0 | x19: ffffffd06d5974c0 x18: 000000000001dad8 | x17: 0000000000000000 x16: dfffffd000000000 | BUG: KASAN: use-after-free in qcom_glink_rpdev_release+0x54/0x70 | x15: ffffffffffffffff x14: 79616c6564203a74 | x13: 0000000000000000 x12: 0000000000000080 | Write of size 8 at addr ffffff83d95768d0 by task kworker/3:1/150 | x11: 0000000000000001 x10: 0000000000000000 | x9 : fc9e8edec0ad0300 x8 : fc9e8edec0ad0300 | | x7 : 0000000000000000 x6 : 0000000000000000 | x5 : 0000000000000080 x4 : 0000000000000000 | CPU: 3 PID: 150 Comm: kworker/3:1 Tainted: G W 5.4.147-lockdep #1 | x3 : ffffffd06c149574 x2 : ffffff83f77f7498 | x1 : ffffffd06d596f60 x0 : 0000000000000061 | Hardware name: Google CoachZ (rev1 - 2) with LTE (DT) | Call trace: | debug_print_object+0x13c/0x1b0 | Workqueue: events kobject_delayed_cleanup | __debug_check_no_obj_freed+0x25c/0x3c0 | debug_check_no_obj_freed+0x18/0x20 | Call trace: | slab_free_freelist_hook+0xb4/0x1bc | kfree+0xe8/0x2d8 | dump_backtrace+0x0/0x27c | rpmsg_ctrldev_release_device+0x78/0xb8 | device_release+0x68/0x14c | show_stack+0x20/0x2c | kobject_cleanup+0x12c/0x298 | kobject_delayed_cleanup+0x10/0x18 | dump_stack+0xe0/0x19c | process_one_work+0x578/0x92c | worker_thread+0x804/0xcf8 | print_address_description+0x3c/0x4a8 | kthread+0x2a8/0x314 | ret_from_fork+0x10/0x18 | __kasan_report+0x100/0x124 Signed-off-by: Sujit Kautkar <sujitka@chromium.org> --- (no changes since v1) drivers/rpmsg/rpmsg_char.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)