bisecting cause commit starting from f8e6dfc64f6135d1b6c5215c14cd30b9b60a0008 building syzkaller on 3fd2ea69e05557e7e0fef9b68263b4150670671c testing commit f8e6dfc64f6135d1b6c5215c14cd30b9b60a0008 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: d7acd20e250d0cc860133798a99a9cd7396c1c1961306e794675fd531ee70707 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in drop_current_rng run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register run #10: crashed: INFO: task hung in drop_current_rng run #11: crashed: INFO: task hung in drop_current_rng run #12: crashed: INFO: task hung in drop_current_rng run #13: crashed: INFO: task hung in drop_current_rng run #14: crashed: INFO: task hung in hwrng_register run #15: crashed: INFO: task hung in hwrng_register run #16: crashed: INFO: task hung in drop_current_rng run #17: crashed: INFO: task hung in hwrng_register run #18: crashed: INFO: task hung in drop_current_rng run #19: crashed: INFO: task hung in hwrng_register testing release v5.13 testing commit 62fb9874f5da54fdb243003b386128037319b219 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: 160dd584d3041427002e5e881f98280ae9aebc819a2fa29b4bade4d15820e761 all runs: crashed: INFO: task hung in hwrng_register testing release v5.12 testing commit 9f4ad9e425a1d3b6a34617b8ea226d56a119a717 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: b8cac70814a5fdbac7dbdd38e4214f03832ce2c4fc4b950864fc4c971afa2790 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in drop_current_rng run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register testing release v5.11 testing commit f40ddce88593482919761f74910f42f4b84c004b compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: f1d0cb916adcced6b6c9b2da961ed8830a0d6725dbc70234a7a33626cd76aafe run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in drop_current_rng run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register testing release v5.10 testing commit 2c85ebc57b3e1817b6ce1a6b703928e113a90442 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: 2a15a524b9eccf3c507e1d167d1c435a69c6d207f31bdd5162bf857cc86a1af3 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in drop_current_rng run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in drop_current_rng run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in drop_current_rng testing release v5.9 testing commit bbf5c979011a099af5dc76498918ed7df445635b compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: fd0a4e27ddcd396e6415d61f52a4ec85945b9492ec87a9a09a1dc277dacafb15 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in drop_current_rng run #3: crashed: INFO: task hung in drop_current_rng run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in drop_current_rng run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register testing release v5.8 testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c compiler: gcc (GCC) 8.4.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: ecc34ef178adc7c0ca647a2fd494eeee0344ca866c6a5ab62d83419013222c3a run #0: crashed: INFO: task hung in drop_current_rng run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in drop_current_rng run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in drop_current_rng run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 compiler: gcc version 8.4.1 20210217 (GCC), GNU ld (GNU Binutils for Debian) 2.35.1 kernel signature: 9b2bcabc91b7407d6b2c675a877e63ee5d45ce60cfeaa5d0ca1583b7952c51da run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in drop_current_rng run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 9022ef7263f3ac71b54b2d8852435853b3fd50cf19c59acd4b3401ba939ff3bf all runs: OK # git bisect start 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 7111951b8d4973bda27ff663f2cf18b663d15b48 Bisecting: 7542 revisions left to test after this (roughly 13 steps) [50a5de895dbe5df947b3a695777db5b2c313e065] Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma testing commit 50a5de895dbe5df947b3a695777db5b2c313e065 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 362e02883c9067e1bd7735f739adbc21a32deab643d9f461fe0483d1cb2f57f1 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in drop_current_rng run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in drop_current_rng run #6: crashed: INFO: task hung in drop_current_rng run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in drop_current_rng # git bisect bad 50a5de895dbe5df947b3a695777db5b2c313e065 Bisecting: 4204 revisions left to test after this (roughly 12 steps) [56a451b780676bc1cdac011735fe2869fa2e9abf] Merge tag 'ntb-5.7' of git://github.com/jonmason/ntb testing commit 56a451b780676bc1cdac011735fe2869fa2e9abf compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 346318984c573b425f17f097408d2b8285b80cfab2592d6bcdbd52559795cf35 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in drop_current_rng run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register # git bisect bad 56a451b780676bc1cdac011735fe2869fa2e9abf Bisecting: 1643 revisions left to test after this (roughly 11 steps) [49835c15a55225e9b3ff9cc9317135b334ea2d49] Merge tag 'pm-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm testing commit 49835c15a55225e9b3ff9cc9317135b334ea2d49 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 73443d5697eb60046caa8a99f3abf6026b444a3659c07b13a293f71ee8619ffe run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in drop_current_rng run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register # git bisect bad 49835c15a55225e9b3ff9cc9317135b334ea2d49 Bisecting: 934 revisions left to test after this (roughly 10 steps) [063d1942247668eb0bb800aef5afbbef337344be] Merge tag 'media/v5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media testing commit 063d1942247668eb0bb800aef5afbbef337344be compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: acb8cdd7f1e3d02e0f62dc01a862cc82d57f84dee0891f01c052e9b8d9bb1ee9 all runs: OK # git bisect good 063d1942247668eb0bb800aef5afbbef337344be Bisecting: 516 revisions left to test after this (roughly 9 steps) [e681bb287f40e7a9dbcb04cef80fd87a2511ab86] staging: vt6656: Use DIV_ROUND_UP macro instead of specific code testing commit e681bb287f40e7a9dbcb04cef80fd87a2511ab86 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: edc7a4fafd84c7ba4231acee75aefed2a306dee005c1f3bee15f71e964c9178d all runs: OK # git bisect good e681bb287f40e7a9dbcb04cef80fd87a2511ab86 Bisecting: 266 revisions left to test after this (roughly 8 steps) [db34c5ffee649e2c4c870d1031a996398a187cf5] Merge tag 'usb-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb testing commit db34c5ffee649e2c4c870d1031a996398a187cf5 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 972e9eec9631331c787feee9dfb6bf8829cfdee9444528dacbfd81e8e3b6ea41 run #0: crashed: INFO: task hung in drop_current_rng run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register # git bisect bad db34c5ffee649e2c4c870d1031a996398a187cf5 Bisecting: 121 revisions left to test after this (roughly 7 steps) [a8ab3e76297ea85d92f4ee0833bd469816a13ccf] Merge tag 'usb-for-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next testing commit a8ab3e76297ea85d92f4ee0833bd469816a13ccf compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 03ba6cce89ce58b3532f128e2ba1d65dc72666c7808282e77da3aa239c4230c8 all runs: crashed: INFO: task hung in hwrng_register # git bisect bad a8ab3e76297ea85d92f4ee0833bd469816a13ccf Bisecting: 63 revisions left to test after this (roughly 6 steps) [d1c6a769cdf466053ae211789f2b0671c8a72331] usb: typec: mux: Allow the mux handles to be requested with fwnode testing commit d1c6a769cdf466053ae211789f2b0671c8a72331 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: d8967c433a65c8ccefe0cde3c4677ed84351de9a6fe38efd890981c38964d3d9 all runs: OK # git bisect good d1c6a769cdf466053ae211789f2b0671c8a72331 Bisecting: 31 revisions left to test after this (roughly 5 steps) [eeead847487f726fa177d0f4060c4f0816ad9cd9] usb: gadget: amd5536udc: fix spelling mistake "reserverd" -> "reserved" testing commit eeead847487f726fa177d0f4060c4f0816ad9cd9 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 67f8706f2568a5348f815619f22fe826a4ed1e65855c124ebba091875453ba92 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in drop_current_rng run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in drop_current_rng run #8: crashed: INFO: task hung in drop_current_rng run #9: crashed: INFO: task hung in hwrng_register # git bisect bad eeead847487f726fa177d0f4060c4f0816ad9cd9 Bisecting: 15 revisions left to test after this (roughly 4 steps) [3d157c28d2289edf0439e8308e8de3a06acaaf0e] doc: dt: bindings: usb: dwc3: Update entries for disabling SS instances in park mode testing commit 3d157c28d2289edf0439e8308e8de3a06acaaf0e compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 6540f7e605d2a8fdd23469c3592e9adffb87e32faa1b12ff380ca214850f11fe run #0: OK run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: boot failed: can't ssh into the instance # git bisect good 3d157c28d2289edf0439e8308e8de3a06acaaf0e Bisecting: 7 revisions left to test after this (roughly 3 steps) [0227cc84c44417a29c8102e41db8ec2c11ebc6b2] usb: dwc3: core: don't do suspend for device mode if already suspended testing commit 0227cc84c44417a29c8102e41db8ec2c11ebc6b2 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 3b8ea8d2832b0eb5e232787f8c21c7376f1e9fe2e2512cd7dccbef04a7f1322e all runs: OK # git bisect good 0227cc84c44417a29c8102e41db8ec2c11ebc6b2 Bisecting: 3 revisions left to test after this (roughly 2 steps) [95b18f28979e12539cc02f6ec4e2c776e8551f39] dt-bindings: usb: dwc2: add compatible property for rk3328 usb testing commit 95b18f28979e12539cc02f6ec4e2c776e8551f39 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: e87bb3478cdc2d81109fe9ac6dda80e34ca3e20819b9308fe264607bd35c1743 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in hwrng_register run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in drop_current_rng run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: crashed: INFO: task hung in hwrng_register # git bisect bad 95b18f28979e12539cc02f6ec4e2c776e8551f39 Bisecting: 1 revision left to test after this (roughly 1 step) [1a0808cb9e417170ed6ab97254cf319dc3e3c310] usb: dwc2: Implement set_selfpowered() testing commit 1a0808cb9e417170ed6ab97254cf319dc3e3c310 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 3b8ea8d2832b0eb5e232787f8c21c7376f1e9fe2e2512cd7dccbef04a7f1322e all runs: OK # git bisect good 1a0808cb9e417170ed6ab97254cf319dc3e3c310 Bisecting: 0 revisions left to test after this (roughly 0 steps) [f2c2e717642c66f7fe7e5dd69b2e8ff5849f4d10] usb: gadget: add raw-gadget interface testing commit f2c2e717642c66f7fe7e5dd69b2e8ff5849f4d10 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: e87bb3478cdc2d81109fe9ac6dda80e34ca3e20819b9308fe264607bd35c1743 run #0: crashed: INFO: task hung in hwrng_register run #1: crashed: INFO: task hung in hwrng_register run #2: crashed: INFO: task hung in hwrng_register run #3: crashed: INFO: task hung in hwrng_register run #4: crashed: INFO: task hung in drop_current_rng run #5: crashed: INFO: task hung in hwrng_register run #6: crashed: INFO: task hung in hwrng_register run #7: crashed: INFO: task hung in hwrng_register run #8: crashed: INFO: task hung in hwrng_register run #9: boot failed: can't ssh into the instance # git bisect bad f2c2e717642c66f7fe7e5dd69b2e8ff5849f4d10 f2c2e717642c66f7fe7e5dd69b2e8ff5849f4d10 is the first bad commit commit f2c2e717642c66f7fe7e5dd69b2e8ff5849f4d10 Author: Andrey Konovalov Date: Mon Feb 24 17:13:03 2020 +0100 usb: gadget: add raw-gadget interface USB Raw Gadget is a kernel module that provides a userspace interface for the USB Gadget subsystem. Essentially it allows to emulate USB devices from userspace. Enabled with CONFIG_USB_RAW_GADGET. Raw Gadget is currently a strictly debugging feature and shouldn't be used in production. Raw Gadget is similar to GadgetFS, but provides a more low-level and direct access to the USB Gadget layer for the userspace. The key differences are: 1. Every USB request is passed to the userspace to get a response, while GadgetFS responds to some USB requests internally based on the provided descriptors. However note, that the UDC driver might respond to some requests on its own and never forward them to the Gadget layer. 2. GadgetFS performs some sanity checks on the provided USB descriptors, while Raw Gadget allows you to provide arbitrary data as responses to USB requests. 3. Raw Gadget provides a way to select a UDC device/driver to bind to, while GadgetFS currently binds to the first available UDC. 4. Raw Gadget uses predictable endpoint names (handles) across different UDCs (as long as UDCs have enough endpoints of each required transfer type). 5. Raw Gadget has ioctl-based interface instead of a filesystem-based one. Reviewed-by: Greg Kroah-Hartman Signed-off-by: Andrey Konovalov Signed-off-by: Felipe Balbi Documentation/usb/index.rst | 1 + Documentation/usb/raw-gadget.rst | 61 ++ drivers/usb/gadget/legacy/Kconfig | 11 + drivers/usb/gadget/legacy/Makefile | 1 + drivers/usb/gadget/legacy/raw_gadget.c | 1078 ++++++++++++++++++++++++++++++++ include/uapi/linux/usb/raw_gadget.h | 167 +++++ 6 files changed, 1319 insertions(+) create mode 100644 Documentation/usb/raw-gadget.rst create mode 100644 drivers/usb/gadget/legacy/raw_gadget.c create mode 100644 include/uapi/linux/usb/raw_gadget.h culprit signature: e87bb3478cdc2d81109fe9ac6dda80e34ca3e20819b9308fe264607bd35c1743 parent signature: 3b8ea8d2832b0eb5e232787f8c21c7376f1e9fe2e2512cd7dccbef04a7f1322e revisions tested: 23, total time: 5h12m33.196417363s (build: 2h28m9.144237813s, test: 2h41m49.404051087s) first bad commit: f2c2e717642c66f7fe7e5dd69b2e8ff5849f4d10 usb: gadget: add raw-gadget interface recipients (to): ["andreyknvl@google.com" "balbi@kernel.org" "gregkh@linuxfoundation.org"] recipients (cc): [] crash: INFO: task hung in hwrng_register INFO: task kworker/0:0:5 blocked for more than 143 seconds. Not tainted 5.6.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:0 D25320 5 2 0x80084000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xc4/0x2b0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x8db/0x1400 kernel/locking/mutex.c:1103 hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 chaoskey_probe+0x6c8/0xb27 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x277/0x840 drivers/usb/core/driver.c:361 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_set_configuration+0xc81/0x1940 drivers/usb/core/message.c:2023 generic_probe+0x61/0x8a drivers/usb/core/generic.c:210 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_new_device+0x866/0x14e0 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1079/0x3240 drivers/usb/core/hub.c:5563 process_one_work+0x8ff/0x1690 kernel/workqueue.c:2264 worker_thread+0x82/0xb50 kernel/workqueue.c:2410 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/0:1:7 blocked for more than 143 seconds. Not tainted 5.6.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:1 D25344 7 2 0x80084000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xc4/0x2b0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x8db/0x1400 kernel/locking/mutex.c:1103 hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 chaoskey_probe+0x6c8/0xb27 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x277/0x840 drivers/usb/core/driver.c:361 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_set_configuration+0xc81/0x1940 drivers/usb/core/message.c:2023 generic_probe+0x61/0x8a drivers/usb/core/generic.c:210 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_new_device+0x866/0x14e0 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1079/0x3240 drivers/usb/core/hub.c:5563 process_one_work+0x8ff/0x1690 kernel/workqueue.c:2264 worker_thread+0x82/0xb50 kernel/workqueue.c:2410 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/1:4:3141 blocked for more than 144 seconds. Not tainted 5.6.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:4 D25576 3141 2 0x80084000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xc4/0x2b0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x8db/0x1400 kernel/locking/mutex.c:1103 hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 chaoskey_probe+0x6c8/0xb27 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x277/0x840 drivers/usb/core/driver.c:361 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_set_configuration+0xc81/0x1940 drivers/usb/core/message.c:2023 generic_probe+0x61/0x8a drivers/usb/core/generic.c:210 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_new_device+0x866/0x14e0 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1079/0x3240 drivers/usb/core/hub.c:5563 process_one_work+0x8ff/0x1690 kernel/workqueue.c:2264 worker_thread+0x82/0xb50 kernel/workqueue.c:2410 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/0:3:3147 blocked for more than 144 seconds. Not tainted 5.6.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:3 D25208 3147 2 0x80084000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xc4/0x2b0 kernel/sched/core.c:4154 schedule_timeout+0x6b5/0xe80 kernel/time/timer.c:1871 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x25f/0x3c0 kernel/sched/completion.c:136 cleanup_rng drivers/char/hw_random/core.c:81 [inline] kref_put include/linux/kref.h:65 [inline] drop_current_rng+0x79/0xb0 drivers/char/hw_random/core.c:109 set_current_rng+0x1fc/0x360 drivers/char/hw_random/core.c:96 hwrng_register+0x358/0x530 drivers/char/hw_random/core.c:505 chaoskey_probe+0x6c8/0xb27 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x277/0x840 drivers/usb/core/driver.c:361 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_set_configuration+0xc81/0x1940 drivers/usb/core/message.c:2023 generic_probe+0x61/0x8a drivers/usb/core/generic.c:210 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_new_device+0x866/0x14e0 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1079/0x3240 drivers/usb/core/hub.c:5563 process_one_work+0x8ff/0x1690 kernel/workqueue.c:2264 worker_thread+0x82/0xb50 kernel/workqueue.c:2410 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/0:4:8715 blocked for more than 145 seconds. Not tainted 5.6.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:4 D25528 8715 2 0x80084000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xc4/0x2b0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x8db/0x1400 kernel/locking/mutex.c:1103 hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 chaoskey_probe+0x6c8/0xb27 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x277/0x840 drivers/usb/core/driver.c:361 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_set_configuration+0xc81/0x1940 drivers/usb/core/message.c:2023 generic_probe+0x61/0x8a drivers/usb/core/generic.c:210 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_new_device+0x866/0x14e0 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1079/0x3240 drivers/usb/core/hub.c:5563 process_one_work+0x8ff/0x1690 kernel/workqueue.c:2264 worker_thread+0x82/0xb50 kernel/workqueue.c:2410 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task kworker/0:5:10175 blocked for more than 145 seconds. Not tainted 5.6.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:5 D24144 10175 2 0x80084000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xc4/0x2b0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x8db/0x1400 kernel/locking/mutex.c:1103 hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 chaoskey_probe+0x6c8/0xb27 drivers/usb/misc/chaoskey.c:205 usb_probe_interface+0x277/0x840 drivers/usb/core/driver.c:361 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_set_configuration+0xc81/0x1940 drivers/usb/core/message.c:2023 generic_probe+0x61/0x8a drivers/usb/core/generic.c:210 really_probe+0x20b/0xb00 drivers/base/dd.c:551 driver_probe_device+0x259/0x370 drivers/base/dd.c:724 bus_for_each_drv+0x118/0x1b0 drivers/base/bus.c:431 __device_attach+0x1be/0x2e0 drivers/base/dd.c:897 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x10f7/0x1920 drivers/base/core.c:2500 usb_new_device+0x866/0x14e0 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1079/0x3240 drivers/usb/core/hub.c:5563 process_one_work+0x8ff/0x1690 kernel/workqueue.c:2264 worker_thread+0x82/0xb50 kernel/workqueue.c:2410 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 6 locks held by kworker/0:0/5: #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x80b/0x1690 kernel/workqueue.c:2235 #1: ffffc90000cbfe00 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x840/0x1690 kernel/workqueue.c:2239 #2: ffff8880a7fa0200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8880a7fa0200 (&dev->mutex){....}, at: hub_event+0x143/0x3240 drivers/usb/core/hub.c:5509 #3: ffff8880980b2200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8880980b2200 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #4: ffff8880ab83f190 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #4: ffff8880ab83f190 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #5: ffffffff8afebda0 (rng_mutex){+.+.}, at: hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 6 locks held by kworker/0:1/7: #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x80b/0x1690 kernel/workqueue.c:2235 #1: ffffc90000cdfe00 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x840/0x1690 kernel/workqueue.c:2239 #2: ffff88823606d200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff88823606d200 (&dev->mutex){....}, at: hub_event+0x143/0x3240 drivers/usb/core/hub.c:5509 #3: ffff8880af4de200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8880af4de200 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #4: ffff8880a8e5a190 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #4: ffff8880a8e5a190 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #5: ffffffff8afebda0 (rng_mutex){+.+.}, at: hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 1 lock held by khungtaskd/1556: #0: ffffffff8a2e1100 (rcu_read_lock){....}, at: debug_show_all_locks+0x52/0x2b9 kernel/locking/lockdep.c:5331 6 locks held by kworker/1:4/3141: #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x80b/0x1690 kernel/workqueue.c:2235 #1: ffffc90001a37e00 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x840/0x1690 kernel/workqueue.c:2239 #2: ffff8880a7f93200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8880a7f93200 (&dev->mutex){....}, at: hub_event+0x143/0x3240 drivers/usb/core/hub.c:5509 #3: ffff8880ac26f200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8880ac26f200 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #4: ffff88809d3b8190 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #4: ffff88809d3b8190 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #5: ffffffff8afebda0 (rng_mutex){+.+.}, at: hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 6 locks held by kworker/0:3/3147: #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x80b/0x1690 kernel/workqueue.c:2235 #1: ffffc900010d7e00 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x840/0x1690 kernel/workqueue.c:2239 #2: ffff8880a7e1a200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8880a7e1a200 (&dev->mutex){....}, at: hub_event+0x143/0x3240 drivers/usb/core/hub.c:5509 #3: ffff888096a7d200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff888096a7d200 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #4: ffff8880abaaf190 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #4: ffff8880abaaf190 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #5: ffffffff8afebda0 (rng_mutex){+.+.}, at: hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 1 lock held by in:imklog/8073: #0: ffff8880ac21ee20 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x96/0xb0 fs/file.c:821 3 locks held by rs:main Q:Reg/8075: #0: ffff8880b9e522d8 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1215 [inline] #0: ffff8880b9e522d8 (&rq->lock){-.-.}, at: __schedule+0x2b5/0x1f90 kernel/sched/core.c:4028 #1: ffffffff8a2e1100 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:435 [inline] #1: ffffffff8a2e1100 (rcu_read_lock){....}, at: update_curr+0x2ec/0x860 kernel/sched/fair.c:859 #2: ffff888091ea67c8 (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_lock include/linux/fs.h:791 [inline] #2: ffff888091ea67c8 (&sb->s_type->i_mutex_key#10){+.+.}, at: ext4_buffered_write_iter+0x94/0x3d0 fs/ext4/file.c:264 6 locks held by kworker/0:4/8715: #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x80b/0x1690 kernel/workqueue.c:2235 #1: ffffc90001f17e00 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x840/0x1690 kernel/workqueue.c:2239 #2: ffff8882360c2200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8882360c2200 (&dev->mutex){....}, at: hub_event+0x143/0x3240 drivers/usb/core/hub.c:5509 #3: ffff8880b0578200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8880b0578200 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #4: ffff8880a88e0190 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #4: ffff8880a88e0190 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #5: ffffffff8afebda0 (rng_mutex){+.+.}, at: hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 6 locks held by kworker/0:5/10175: #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880af6ec528 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x80b/0x1690 kernel/workqueue.c:2235 #1: ffffc9000a107e00 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x840/0x1690 kernel/workqueue.c:2239 #2: ffff888236042200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff888236042200 (&dev->mutex){....}, at: hub_event+0x143/0x3240 drivers/usb/core/hub.c:5509 #3: ffff8880b1fe8200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8880b1fe8200 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #4: ffff8880afc8c190 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #4: ffff8880afc8c190 (&dev->mutex){....}, at: __device_attach+0x76/0x2e0 drivers/base/dd.c:874 #5: ffffffff8afebda0 (rng_mutex){+.+.}, at: hwrng_register+0x6b/0x530 drivers/char/hw_random/core.c:478 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1556 Comm: khungtaskd Not tainted 5.6.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x96/0xe0 lib/dump_stack.c:118 nmi_cpu_backtrace.cold.6+0x2e/0x33 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x183/0x1ac lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0x69d/0xd50 kernel/hung_task.c:289 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle+0x25/0x310 arch/x86/kernel/process.c:695