Hi Paul, On Mon, Jan 29, 2024 at 10:27:44PM +0100, Paul Menzel wrote: > Dear Christian, > > > Am 29.01.24 um 20:06 schrieb Christian A. Ehrhardt: > > > On Mon, Jan 29, 2024 at 12:57:11PM +0100, Paul Menzel wrote: > > > > I noticed the message first time with Linux 6.6.8 on December 26th, and also > > > with 6.6.11, 6.7 and 6.7.1. I am unsure how to reproduce it though. > > > > > > Here the trace from Linux 6.7.1-1~exp1: > > > > > > ``` > > > [ 0.000000] Linux version 6.7-amd64 (debian-kernel@xxxxxxxxxxxxxxxx) (x86_64-linux-gnu-gcc-13 (Debian 13.2.0-10) 13.2.0, GNU ld (GNU Binutils for Debian) 2.41.90.20240115) #1 SMP PREEMPT_DYNAMIC Debian 6.7.1-1~exp1 (2024-01-22) > > > […] > > > [ 0.000000] DMI: Dell Inc. XPS 13 9360/0596KF, BIOS 2.21.0 06/02/2022 > > > […] > > > [ 9068.294345] ucsi_acpi USBC000:00: failed to re-enable notifications (-110) > > > [ 9068.499156] ------------[ cut here ]------------ > > > [ 9068.499172] refcount_t: underflow; use-after-free. > > > [ 9068.499199] WARNING: CPU: 0 PID: 5598 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110 > > […] > > > [ 9068.499517] Call Trace: > > > [ 9068.499521] <TASK> > > > [ 9068.499522] ? refcount_warn_saturate+0xbe/0x110 > > > [ 9068.499526] ? __warn+0x81/0x130 > > > [ 9068.499533] ? refcount_warn_saturate+0xbe/0x110 > > > [ 9068.499545] ? report_bug+0x171/0x1a0 > > > [ 9068.499549] ? console_unlock+0x78/0x120 > > > [ 9068.499553] ? handle_bug+0x3c/0x80 > > > [ 9068.499557] ? exc_invalid_op+0x17/0x70 > > > [ 9068.499565] ? asm_exc_invalid_op+0x1a/0x20 > > > [ 9068.499570] ? refcount_warn_saturate+0xbe/0x110 > > > [ 9068.499576] typec_altmode_release+0x49/0xc0 [typec] > > > [ 9068.499615] device_release+0x34/0x90 > > > [ 9068.499624] kobject_put+0x78/0x190 > > > [ 9068.499629] ucsi_unregister_altmodes+0x41/0xa0 [typec_ucsi] > > > [ 9068.499648] ucsi_unregister_partner.part.0+0x77/0xa0 [typec_ucsi] > > > [ 9068.499662] ucsi_handle_connector_change+0x1bb/0x310 [typec_ucsi] > > > [ 9068.499671] process_one_work+0x171/0x340 > > > [ 9068.499676] worker_thread+0x27b/0x3a0 > > > [ 9068.499679] ? __pfx_worker_thread+0x10/0x10 > > > [ 9068.499681] kthread+0xe5/0x120 > > > [ 9068.499690] ? __pfx_kthread+0x10/0x10 > > > [ 9068.499693] ret_from_fork+0x31/0x50 > > > [ 9068.499698] ? __pfx_kthread+0x10/0x10 > > > [ 9068.499700] ret_from_fork_asm+0x1b/0x30 > > > [ 9068.499714] </TASK> > > > [ 9068.499715] ---[ end trace 0000000000000000 ]--- > > > ``` > > > > > > Please find the full output of `dmesg` attached. > > > > This should be fixed by > > > > | commit 5962ded777d689cd8bf04454273e32228d7fb71f > > | Author: RD Babiera <rdbabiera@xxxxxxxxxx> > > | Date: Wed Jan 3 18:17:55 2024 +0000 > > | > > | usb: typec: class: fix typec_altmode_put_partner to put plugs > > > > which is in mainline and 6.7.2. > > Awesome. Thank you for mentioning this, and nice timing, as the commit > referenced in the Fixed-by tag is from v4.19-rc1 from August 2018. ;-) A first attempt to fix that 2018 commit made it into 6.7 and caused the regression and the warning (b17b7fe6dd5c). This commit was then reverted (9c6b789e954f). The final fix (5962ded777d6) is a new version of the reverted fix that does not cause regressions. The Fixes: tag for the revert does point into the post 6.7 range. regards Christian