bisecting cause commit starting from c11d28ab4a691736e30b49813fb801847bd44e83 building syzkaller on 9682898d6f14dd27f95c419d059fd867bb91b22b testing commit c11d28ab4a691736e30b49813fb801847bd44e83 with gcc (GCC) 8.1.0 kernel signature: 810ef2efb0c56dbedc37710658b8ab814d99af1c90bcf075332aca278f09209f all runs: crashed: KASAN: use-after-free Read in i2cdev_notifier_call testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.1.0 kernel signature: 2f0bd3fb31b29bc43cc5b47439e34fee35885b568ed17dc921849b04189a9a2f all runs: OK # git bisect start c11d28ab4a691736e30b49813fb801847bd44e83 7111951b8d4973bda27ff663f2cf18b663d15b48 Bisecting: 13326 revisions left to test after this (roughly 14 steps) [74cd3984f13381049627cfa260fd87e6fcd31add] media: imx: utils: Split find|enum_format into fourcc and mbus functions testing commit 74cd3984f13381049627cfa260fd87e6fcd31add with gcc (GCC) 8.1.0 kernel signature: a5243547f81ecf6a90e73f3ca58bf94142694c9920019b0af11a6670075735da all runs: OK # git bisect good 74cd3984f13381049627cfa260fd87e6fcd31add Bisecting: 6630 revisions left to test after this (roughly 13 steps) [8bf9e28a25c6bbff58513b8175620e096368ede4] Merge remote-tracking branch 'net-next/master' testing commit 8bf9e28a25c6bbff58513b8175620e096368ede4 with gcc (GCC) 8.1.0 kernel signature: 72fde4eacd844e3061e59afaa204540ae81616ebb50f97ffd98e800945518ff5 all runs: crashed: KASAN: use-after-free Read in i2cdev_notifier_call # git bisect bad 8bf9e28a25c6bbff58513b8175620e096368ede4 Bisecting: 3347 revisions left to test after this (roughly 12 steps) [e0b0f9fd6d0a1f228f3c09958e25def4865454db] Merge remote-tracking branch 'sh/sh-next' testing commit e0b0f9fd6d0a1f228f3c09958e25def4865454db with gcc (GCC) 8.1.0 kernel signature: 7c916516a6179e8d8bc1350bfa5ba1d6f0613c119548f3676e01cea7747ebb76 all runs: crashed: KASAN: use-after-free Read in i2cdev_notifier_call # git bisect bad e0b0f9fd6d0a1f228f3c09958e25def4865454db Bisecting: 1671 revisions left to test after this (roughly 11 steps) [7e71515c910d8a1ce0a780982f41f921616a97d6] Merge remote-tracking branch 'drm-fixes/drm-fixes' testing commit 7e71515c910d8a1ce0a780982f41f921616a97d6 with gcc (GCC) 8.1.0 kernel signature: a5ebf5a7eb7f7a5ca16b7a0b2263dc53ded32eea6ccc8f85c1e3da3c183fe0d3 all runs: crashed: KASAN: use-after-free Read in i2cdev_notifier_call # git bisect bad 7e71515c910d8a1ce0a780982f41f921616a97d6 Bisecting: 837 revisions left to test after this (roughly 10 steps) [17e34526f0a8f81a214d1ee6f7d8ad2a9c9bae33] mm/vmscan: remove unnecessary argument description of isolate_lru_pages() testing commit 17e34526f0a8f81a214d1ee6f7d8ad2a9c9bae33 with gcc (GCC) 8.1.0 kernel signature: 6324d032af5b648cd4e41b0912677c6669fd3fa5636286c7ee04df8002a47799 all runs: OK # git bisect good 17e34526f0a8f81a214d1ee6f7d8ad2a9c9bae33 Bisecting: 419 revisions left to test after this (roughly 9 steps) [d69100b8eee27c2d60ee52df76e0b80a8d492d34] net: nlmsg_cancel() if put fails for nhmsg testing commit d69100b8eee27c2d60ee52df76e0b80a8d492d34 with gcc (GCC) 8.1.0 kernel signature: 574a23a5938dab3bc43b7f07be688ba9c358018ba69a4fc3b37ce6d8dc8a53f7 all runs: OK # git bisect good d69100b8eee27c2d60ee52df76e0b80a8d492d34 Bisecting: 213 revisions left to test after this (roughly 8 steps) [03fb3acae4be8a6b680ffedb220a8b6c07260b40] Merge branch 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux testing commit 03fb3acae4be8a6b680ffedb220a8b6c07260b40 with gcc (GCC) 8.1.0 kernel signature: 65ec3d16daa1d6d2c6ff8c7c70cfe7efaa1b798588d62750dd3b988446494e78 all runs: OK # git bisect good 03fb3acae4be8a6b680ffedb220a8b6c07260b40 Bisecting: 105 revisions left to test after this (roughly 7 steps) [4aada7791fa2bd3e927502bc67ba604b95bb21bf] Merge remote-tracking branch 'sound-current/for-linus' testing commit 4aada7791fa2bd3e927502bc67ba604b95bb21bf with gcc (GCC) 8.1.0 kernel signature: 3c55137eeccbf397c586b5fac1dd2026a9c6de0c52fdf0b40562434aa5c74e6e all runs: OK # git bisect good 4aada7791fa2bd3e927502bc67ba604b95bb21bf Bisecting: 53 revisions left to test after this (roughly 6 steps) [078c7b0d185f6c1065afa4e4ac3389beece7d503] Merge remote-tracking branch 'tty.current/tty-linus' testing commit 078c7b0d185f6c1065afa4e4ac3389beece7d503 with gcc (GCC) 8.1.0 kernel signature: f6602d58aa2c1dcb940b105a06a469fd93cd30c28c070ff2de133d27a35b00ac all runs: crashed: KASAN: use-after-free Read in i2cdev_notifier_call # git bisect bad 078c7b0d185f6c1065afa4e4ac3389beece7d503 Bisecting: 25 revisions left to test after this (roughly 5 steps) [e881587896db7a10902579c44350a01f7557a6d8] Merge remote-tracking branch 'asoc/for-5.7' into asoc-linus testing commit e881587896db7a10902579c44350a01f7557a6d8 with gcc (GCC) 8.1.0 kernel signature: 98cff9606ef8ae539f42215d56fe4f90f54b6617d4a0d2df6b993bb42ea4b1cf all runs: OK # git bisect good e881587896db7a10902579c44350a01f7557a6d8 Bisecting: 13 revisions left to test after this (roughly 4 steps) [83c813e237b8edf0fe8184ccdf3dc9622202084c] Merge remote-tracking branch 'spi/for-5.7' into spi-linus testing commit 83c813e237b8edf0fe8184ccdf3dc9622202084c with gcc (GCC) 8.1.0 kernel signature: ea66a30452da18b28f5d06b42aed7dbc03e2677533da2d40b330373025e0b5a3 all runs: OK # git bisect good 83c813e237b8edf0fe8184ccdf3dc9622202084c Bisecting: 6 revisions left to test after this (roughly 3 steps) [66ac4422fa22def9ce0886d3a032c5c288799c87] Merge remote-tracking branch 'regulator-fixes/for-linus' testing commit 66ac4422fa22def9ce0886d3a032c5c288799c87 with gcc (GCC) 8.1.0 kernel signature: e8cafe574b37cc95e9f7bea0b27b42e8b73f2241083dab98306c4e82f752be58 all runs: OK # git bisect good 66ac4422fa22def9ce0886d3a032c5c288799c87 Bisecting: 3 revisions left to test after this (roughly 2 steps) [4ef12f7198023c09ad6d25b652bd8748c965c7fa] kobject: Make sure the parent does not get released before its children testing commit 4ef12f7198023c09ad6d25b652bd8748c965c7fa with gcc (GCC) 8.1.0 kernel signature: 3ae12df4c61dac9a3b5df6777def6e2b52edb743243b81e57b4477d37e963203 all runs: crashed: KASAN: use-after-free Read in i2cdev_notifier_call # git bisect bad 4ef12f7198023c09ad6d25b652bd8748c965c7fa Bisecting: 0 revisions left to test after this (roughly 1 step) [44e960490ddf868fc9135151c4a658936e771dc2] driver core: Fix handling of SYNC_STATE_ONLY + STATELESS device links testing commit 44e960490ddf868fc9135151c4a658936e771dc2 with gcc (GCC) 8.1.0 kernel signature: 86c98d341e4bb62773ce87fadbf613ea048bab76244e3d714f4955c4ab234a14 all runs: OK # git bisect good 44e960490ddf868fc9135151c4a658936e771dc2 4ef12f7198023c09ad6d25b652bd8748c965c7fa is the first bad commit commit 4ef12f7198023c09ad6d25b652bd8748c965c7fa Author: Heikki Krogerus Date: Wed May 13 18:18:40 2020 +0300 kobject: Make sure the parent does not get released before its children In the function kobject_cleanup(), kobject_del(kobj) is called before the kobj->release(). That makes it possible to release the parent of the kobject before the kobject itself. To fix that, adding function __kboject_del() that does everything that kobject_del() does except release the parent reference. kobject_cleanup() then calls __kobject_del() instead of kobject_del(), and separately decrements the reference count of the parent kobject after kobj->release() has been called. Reported-by: Naresh Kamboju Reported-by: kernel test robot Fixes: 7589238a8cf3 ("Revert "software node: Simplify software_node_release() function"") Suggested-by: "Rafael J. Wysocki" Signed-off-by: Heikki Krogerus Reviewed-by: Rafael J. Wysocki Reviewed-by: Brendan Higgins Tested-by: Brendan Higgins Acked-by: Randy Dunlap Link: https://lore.kernel.org/r/20200513151840.36400-1-heikki.krogerus@linux.intel.com Cc: stable Signed-off-by: Greg Kroah-Hartman lib/kobject.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) culprit signature: 3ae12df4c61dac9a3b5df6777def6e2b52edb743243b81e57b4477d37e963203 parent signature: 86c98d341e4bb62773ce87fadbf613ea048bab76244e3d714f4955c4ab234a14 revisions tested: 16, total time: 3h39m53.896589432s (build: 1h35m12.605198651s, test: 2h3m6.632025875s) first bad commit: 4ef12f7198023c09ad6d25b652bd8748c965c7fa kobject: Make sure the parent does not get released before its children cc: ["brendanhiggins@google.com" "gregkh@linuxfoundation.org" "heikki.krogerus@linux.intel.com" "rafael.j.wysocki@intel.com" "rdunlap@infradead.org"] crash: KASAN: use-after-free Read in i2cdev_notifier_call i2c i2c-0: failure reading functionality i2c i2c-0: connected i2c-tiny-usb device usb 1-1: USB disconnect, device number 2 ================================================================== BUG: KASAN: use-after-free in kobject_put+0x1df/0x230 lib/kobject.c:745 Read of size 1 at addr ffff888098413054 by task kworker/0:0/5 CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.7.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x128/0x182 lib/dump_stack.c:118 print_address_description.constprop.8.cold.10+0x9/0x317 mm/kasan/report.c:382 __kasan_report.cold.11+0x35/0x4d mm/kasan/report.c:511 kasan_report+0x32/0x50 mm/kasan/common.c:625 kobject_put+0x1df/0x230 lib/kobject.c:745 i2cdev_detach_adapter drivers/i2c/i2c-dev.c:708 [inline] i2cdev_notifier_call+0x75/0xa0 drivers/i2c/i2c-dev.c:704 notifier_call_chain+0x86/0x150 kernel/notifier.c:83 __blocking_notifier_call_chain kernel/notifier.c:284 [inline] blocking_notifier_call_chain+0x66/0xa0 kernel/notifier.c:295 device_del+0x16b/0xc00 drivers/base/core.c:2708 device_unregister+0x9/0x20 drivers/base/core.c:2766 i2c_del_adapter+0x3ae/0x560 drivers/i2c/i2c-core-base.c:1577 i2c_tiny_usb_disconnect+0x35/0xa0 drivers/i2c/busses/i2c-tiny-usb.c:283 usb_unbind_interface+0x15c/0x870 drivers/usb/core/driver.c:436 __device_release_driver drivers/base/dd.c:1110 [inline] device_release_driver_internal+0x1d2/0x470 drivers/base/dd.c:1141 bus_remove_device+0x293/0x460 drivers/base/bus.c:533 device_del+0x421/0xc00 drivers/base/core.c:2734 usb_disable_device+0x1ae/0x580 drivers/usb/core/message.c:1245 usb_disconnect+0x227/0x850 drivers/usb/core/hub.c:2216 hub_port_connect drivers/usb/core/hub.c:5058 [inline] hub_port_connect_change drivers/usb/core/hub.c:5347 [inline] port_event drivers/usb/core/hub.c:5493 [inline] hub_event+0x1048/0x2d60 drivers/usb/core/hub.c:5575 process_one_work+0x908/0x15d0 kernel/workqueue.c:2268 process_scheduled_works kernel/workqueue.c:2330 [inline] worker_thread+0x5aa/0xb50 kernel/workqueue.c:2416 kthread+0x340/0x410 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Allocated by task 5: save_stack+0x19/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc.constprop.17+0xc1/0xd0 mm/kasan/common.c:495 kmem_cache_alloc_trace+0x156/0x780 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] get_free_i2c_dev drivers/i2c/i2c-dev.c:76 [inline] i2cdev_attach_adapter.part.6+0x81/0x390 drivers/i2c/i2c-dev.c:651 notifier_call_chain+0x86/0x150 kernel/notifier.c:83 __blocking_notifier_call_chain kernel/notifier.c:284 [inline] blocking_notifier_call_chain+0x66/0xa0 kernel/notifier.c:295 device_add+0xa6f/0x1a00 drivers/base/core.c:2524 i2c_register_adapter+0x2a2/0x9d0 drivers/i2c/i2c-core-base.c:1326 i2c_tiny_usb_probe+0x38e/0x4ff drivers/i2c/busses/i2c-tiny-usb.c:265 usb_probe_interface+0x268/0x6c0 drivers/usb/core/driver.c:374 really_probe+0x1f9/0x5e0 drivers/base/dd.c:520 driver_probe_device+0xc9/0x1b0 drivers/base/dd.c:697 bus_for_each_drv+0x117/0x1a0 drivers/base/bus.c:431 __device_attach+0x1be/0x2c0 drivers/base/dd.c:870 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x1089/0x1a00 drivers/base/core.c:2557 usb_set_configuration+0xcc8/0x1640 drivers/usb/core/message.c:2032 usb_generic_driver_probe+0x61/0x90 drivers/usb/core/generic.c:241 usb_probe_device+0x91/0x160 drivers/usb/core/driver.c:272 really_probe+0x1f9/0x5e0 drivers/base/dd.c:520 driver_probe_device+0xc9/0x1b0 drivers/base/dd.c:697 bus_for_each_drv+0x117/0x1a0 drivers/base/bus.c:431 __device_attach+0x1be/0x2c0 drivers/base/dd.c:870 bus_probe_device+0x19e/0x250 drivers/base/bus.c:491 device_add+0x1089/0x1a00 drivers/base/core.c:2557 usb_new_device.cold.66+0x679/0xe85 drivers/usb/core/hub.c:2553 hub_port_connect drivers/usb/core/hub.c:5207 [inline] hub_port_connect_change drivers/usb/core/hub.c:5347 [inline] port_event drivers/usb/core/hub.c:5493 [inline] hub_event+0x15fe/0x2d60 drivers/usb/core/hub.c:5575 process_one_work+0x908/0x15d0 kernel/workqueue.c:2268 worker_thread+0x82/0xb50 kernel/workqueue.c:2414 kthread+0x340/0x410 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Freed by task 5: save_stack+0x19/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kfree+0x107/0x2b0 mm/slab.c:3757 device_release+0x65/0x1c0 drivers/base/core.c:1394 kobject_cleanup lib/kobject.c:701 [inline] kobject_release lib/kobject.c:732 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x12e/0x230 lib/kobject.c:749 put_i2c_dev+0x132/0x190 drivers/i2c/i2c-dev.c:93 i2cdev_detach_adapter drivers/i2c/i2c-dev.c:708 [inline] i2cdev_notifier_call+0x75/0xa0 drivers/i2c/i2c-dev.c:704 notifier_call_chain+0x86/0x150 kernel/notifier.c:83 __blocking_notifier_call_chain kernel/notifier.c:284 [inline] blocking_notifier_call_chain+0x66/0xa0 kernel/notifier.c:295 device_del+0x16b/0xc00 drivers/base/core.c:2708 device_unregister+0x9/0x20 drivers/base/core.c:2766 i2c_del_adapter+0x3ae/0x560 drivers/i2c/i2c-core-base.c:1577 i2c_tiny_usb_disconnect+0x35/0xa0 drivers/i2c/busses/i2c-tiny-usb.c:283 usb_unbind_interface+0x15c/0x870 drivers/usb/core/driver.c:436 __device_release_driver drivers/base/dd.c:1110 [inline] device_release_driver_internal+0x1d2/0x470 drivers/base/dd.c:1141 bus_remove_device+0x293/0x460 drivers/base/bus.c:533 device_del+0x421/0xc00 drivers/base/core.c:2734 usb_disable_device+0x1ae/0x580 drivers/usb/core/message.c:1245 usb_disconnect+0x227/0x850 drivers/usb/core/hub.c:2216 hub_port_connect drivers/usb/core/hub.c:5058 [inline] hub_port_connect_change drivers/usb/core/hub.c:5347 [inline] port_event drivers/usb/core/hub.c:5493 [inline] hub_event+0x1048/0x2d60 drivers/usb/core/hub.c:5575 process_one_work+0x908/0x15d0 kernel/workqueue.c:2268 process_scheduled_works kernel/workqueue.c:2330 [inline] worker_thread+0x5aa/0xb50 kernel/workqueue.c:2416 kthread+0x340/0x410 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 The buggy address belongs to the object at ffff888098413000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 84 bytes inside of 2048-byte region [ffff888098413000, ffff888098413800) The buggy address belongs to the page: page:ffffea00026104c0 refcount:1 mapcount:0 mapping:000000000e783090 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002a4af08 ffffea0002927808 ffff8880aa400e00 raw: 0000000000000000 ffff888098413000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888098412f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888098412f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888098413000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888098413080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888098413100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================