On Mon, Dec 16, 2024 at 01:49:23PM -0800, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 2e7aff49b5da Merge branches 'for-next/core' and 'for-next/.. > git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci > console output: https://syzkaller.appspot.com/x/log.txt?x=17c49be8580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=696fb014d05da3a3 > dashboard link: https://syzkaller.appspot.com/bug?extid=43b8370f38144ca1e467 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > userspace arch: arm64 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/ef408f67fde3/disk-2e7aff49.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/414ac17a20dc/vmlinux-2e7aff49.xz > kernel image: https://storage.googleapis.com/syzbot-assets/a93415d2a7e7/Image-2e7aff49.gz.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+43b8370f38144ca1e467@xxxxxxxxxxxxxxxxxxxxxxxxx bcachefs is broken in it's console_locke usage. -Sima > > ====================================================== > WARNING: possible circular locking dependency detected > 6.13.0-rc2-syzkaller-g2e7aff49b5da #0 Not tainted > ------------------------------------------------------ > syz.3.631/8987 is trying to acquire lock: > ffff0000cc3cd450 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0x9c/0x124 mm/memory.c:6750 > > but task is already holding lock: > ffff80009d267938 (crtc_ww_class_mutex){+.+.}-{0:0}, at: drm_mode_obj_get_properties_ioctl+0x194/0x4fc drivers/gpu/drm/drm_mode_object.c:447 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #8 (crtc_ww_class_mutex){+.+.}-{0:0}: > ww_acquire_init include/linux/ww_mutex.h:162 [inline] > drm_modeset_acquire_init+0x1e4/0x384 drivers/gpu/drm/drm_modeset_lock.c:250 > drmm_mode_config_init+0xb98/0x130c drivers/gpu/drm/drm_mode_config.c:453 > vkms_modeset_init drivers/gpu/drm/vkms/vkms_drv.c:158 [inline] > vkms_create drivers/gpu/drm/vkms/vkms_drv.c:219 [inline] > vkms_init+0x2fc/0x600 drivers/gpu/drm/vkms/vkms_drv.c:256 > do_one_initcall+0x254/0x9f8 init/main.c:1266 > do_initcall_level+0x154/0x214 init/main.c:1328 > do_initcalls+0x58/0xac init/main.c:1344 > do_basic_setup+0x8c/0xa0 init/main.c:1363 > kernel_init_freeable+0x324/0x478 init/main.c:1577 > kernel_init+0x24/0x2a0 init/main.c:1466 > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 > > -> #7 (crtc_ww_class_acquire){+.+.}-{0:0}: > ww_acquire_init include/linux/ww_mutex.h:161 [inline] > drm_modeset_acquire_init+0x1c4/0x384 drivers/gpu/drm/drm_modeset_lock.c:250 > drm_client_modeset_commit_atomic+0xd8/0x724 drivers/gpu/drm/drm_client_modeset.c:1009 > drm_client_modeset_commit_locked+0xd0/0x4a8 drivers/gpu/drm/drm_client_modeset.c:1173 > drm_client_modeset_commit+0x50/0x7c drivers/gpu/drm/drm_client_modeset.c:1199 > __drm_fb_helper_restore_fbdev_mode_unlocked+0xd4/0x178 drivers/gpu/drm/drm_fb_helper.c:237 > drm_fb_helper_set_par+0xc4/0x110 drivers/gpu/drm/drm_fb_helper.c:1351 > fbcon_init+0xf34/0x1eb8 drivers/video/fbdev/core/fbcon.c:1113 > visual_init+0x27c/0x548 drivers/tty/vt/vt.c:1011 > do_bind_con_driver+0x7dc/0xe04 drivers/tty/vt/vt.c:3833 > do_take_over_console+0x4ac/0x5f0 drivers/tty/vt/vt.c:4399 > do_fbcon_takeover+0x158/0x260 drivers/video/fbdev/core/fbcon.c:549 > do_fb_registered drivers/video/fbdev/core/fbcon.c:2988 [inline] > fbcon_fb_registered+0x370/0x4ec drivers/video/fbdev/core/fbcon.c:3008 > do_register_framebuffer drivers/video/fbdev/core/fbmem.c:449 [inline] > register_framebuffer+0x470/0x610 drivers/video/fbdev/core/fbmem.c:515 > __drm_fb_helper_initial_config_and_unlock+0x137c/0x1910 drivers/gpu/drm/drm_fb_helper.c:1841 > drm_fb_helper_initial_config+0x48/0x64 drivers/gpu/drm/drm_fb_helper.c:1906 > drm_fbdev_client_hotplug+0x158/0x22c drivers/gpu/drm/drm_fbdev_client.c:51 > drm_client_register+0x144/0x1e0 drivers/gpu/drm/drm_client.c:140 > drm_fbdev_client_setup+0x1a4/0x39c drivers/gpu/drm/drm_fbdev_client.c:158 > drm_client_setup+0x28/0x9c drivers/gpu/drm/drm_client_setup.c:29 > vkms_create drivers/gpu/drm/vkms/vkms_drv.c:230 [inline] > vkms_init+0x4f0/0x600 drivers/gpu/drm/vkms/vkms_drv.c:256 > do_one_initcall+0x254/0x9f8 init/main.c:1266 > do_initcall_level+0x154/0x214 init/main.c:1328 > do_initcalls+0x58/0xac init/main.c:1344 > do_basic_setup+0x8c/0xa0 init/main.c:1363 > kernel_init_freeable+0x324/0x478 init/main.c:1577 > kernel_init+0x24/0x2a0 init/main.c:1466 > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 > > -> #6 (&client->modeset_mutex){+.+.}-{4:4}: > __mutex_lock_common+0x218/0x28f4 kernel/locking/mutex.c:585 > __mutex_lock kernel/locking/mutex.c:735 [inline] > mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:787 > drm_client_modeset_probe+0x304/0x3f64 drivers/gpu/drm/drm_client_modeset.c:834 > __drm_fb_helper_initial_config_and_unlock+0x104/0x1910 drivers/gpu/drm/drm_fb_helper.c:1818 > drm_fb_helper_initial_config+0x48/0x64 drivers/gpu/drm/drm_fb_helper.c:1906 > drm_fbdev_client_hotplug+0x158/0x22c drivers/gpu/drm/drm_fbdev_client.c:51 > drm_client_register+0x144/0x1e0 drivers/gpu/drm/drm_client.c:140 > drm_fbdev_client_setup+0x1a4/0x39c drivers/gpu/drm/drm_fbdev_client.c:158 > drm_client_setup+0x28/0x9c drivers/gpu/drm/drm_client_setup.c:29 > vkms_create drivers/gpu/drm/vkms/vkms_drv.c:230 [inline] > vkms_init+0x4f0/0x600 drivers/gpu/drm/vkms/vkms_drv.c:256 > do_one_initcall+0x254/0x9f8 init/main.c:1266 > do_initcall_level+0x154/0x214 init/main.c:1328 > do_initcalls+0x58/0xac init/main.c:1344 > do_basic_setup+0x8c/0xa0 init/main.c:1363 > kernel_init_freeable+0x324/0x478 init/main.c:1577 > kernel_init+0x24/0x2a0 init/main.c:1466 > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 > > -> #5 (&helper->lock){+.+.}-{4:4}: > __mutex_lock_common+0x218/0x28f4 kernel/locking/mutex.c:585 > __mutex_lock kernel/locking/mutex.c:735 [inline] > mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:787 > __drm_fb_helper_restore_fbdev_mode_unlocked+0xb4/0x178 drivers/gpu/drm/drm_fb_helper.c:228 > drm_fb_helper_set_par+0xc4/0x110 drivers/gpu/drm/drm_fb_helper.c:1351 > fbcon_init+0xf34/0x1eb8 drivers/video/fbdev/core/fbcon.c:1113 > visual_init+0x27c/0x548 drivers/tty/vt/vt.c:1011 > do_bind_con_driver+0x7dc/0xe04 drivers/tty/vt/vt.c:3833 > do_take_over_console+0x4ac/0x5f0 drivers/tty/vt/vt.c:4399 > do_fbcon_takeover+0x158/0x260 drivers/video/fbdev/core/fbcon.c:549 > do_fb_registered drivers/video/fbdev/core/fbcon.c:2988 [inline] > fbcon_fb_registered+0x370/0x4ec drivers/video/fbdev/core/fbcon.c:3008 > do_register_framebuffer drivers/video/fbdev/core/fbmem.c:449 [inline] > register_framebuffer+0x470/0x610 drivers/video/fbdev/core/fbmem.c:515 > __drm_fb_helper_initial_config_and_unlock+0x137c/0x1910 drivers/gpu/drm/drm_fb_helper.c:1841 > drm_fb_helper_initial_config+0x48/0x64 drivers/gpu/drm/drm_fb_helper.c:1906 > drm_fbdev_client_hotplug+0x158/0x22c drivers/gpu/drm/drm_fbdev_client.c:51 > drm_client_register+0x144/0x1e0 drivers/gpu/drm/drm_client.c:140 > drm_fbdev_client_setup+0x1a4/0x39c drivers/gpu/drm/drm_fbdev_client.c:158 > drm_client_setup+0x28/0x9c drivers/gpu/drm/drm_client_setup.c:29 > vkms_create drivers/gpu/drm/vkms/vkms_drv.c:230 [inline] > vkms_init+0x4f0/0x600 drivers/gpu/drm/vkms/vkms_drv.c:256 > do_one_initcall+0x254/0x9f8 init/main.c:1266 > do_initcall_level+0x154/0x214 init/main.c:1328 > do_initcalls+0x58/0xac init/main.c:1344 > do_basic_setup+0x8c/0xa0 init/main.c:1363 > kernel_init_freeable+0x324/0x478 init/main.c:1577 > kernel_init+0x24/0x2a0 init/main.c:1466 > ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 > > -> #4 (console_lock){+.+.}-{0:0}: > console_lock+0x19c/0x1f4 kernel/printk/printk.c:2833 > __bch2_print_string_as_lines fs/bcachefs/util.c:267 [inline] > bch2_print_string_as_lines+0x2c/0xd4 fs/bcachefs/util.c:286 > __bch2_fsck_err+0x1864/0x2544 fs/bcachefs/error.c:411 > bch2_check_fix_ptr fs/bcachefs/buckets.c:112 [inline] > bch2_check_fix_ptrs+0x15b8/0x515c fs/bcachefs/buckets.c:266 > bch2_trigger_extent+0x71c/0x814 fs/bcachefs/buckets.c:856 > bch2_key_trigger fs/bcachefs/bkey_methods.h:87 [inline] > bch2_gc_mark_key+0x4b4/0xb70 fs/bcachefs/btree_gc.c:634 > bch2_gc_btree fs/bcachefs/btree_gc.c:670 [inline] > bch2_gc_btrees fs/bcachefs/btree_gc.c:729 [inline] > bch2_check_allocations+0x1018/0x48f4 fs/bcachefs/btree_gc.c:1133 > bch2_run_recovery_pass+0xe4/0x1d4 fs/bcachefs/recovery_passes.c:191 > bch2_run_recovery_passes+0x30c/0x73c fs/bcachefs/recovery_passes.c:244 > bch2_fs_recovery+0x32d8/0x55dc fs/bcachefs/recovery.c:861 > bch2_fs_start+0x30c/0x53c fs/bcachefs/super.c:1037 > bch2_fs_get_tree+0x938/0x1030 fs/bcachefs/fs.c:2170 > vfs_get_tree+0x90/0x28c fs/super.c:1814 > do_new_mount+0x278/0x900 fs/namespace.c:3507 > path_mount+0x590/0xe04 fs/namespace.c:3834 > do_mount fs/namespace.c:3847 [inline] > __do_sys_mount fs/namespace.c:4057 [inline] > __se_sys_mount fs/namespace.c:4034 [inline] > __arm64_sys_mount+0x4d4/0x5ac fs/namespace.c:4034 > __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 > el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 > el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 > el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 > > -> #3 (&c->fsck_error_msgs_lock){+.+.}-{4:4}: > __mutex_lock_common+0x218/0x28f4 kernel/locking/mutex.c:585 > __mutex_lock kernel/locking/mutex.c:735 [inline] > mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:787 > __bch2_fsck_err+0x344/0x2544 fs/bcachefs/error.c:282 > bch2_check_fix_ptr fs/bcachefs/buckets.c:112 [inline] > bch2_check_fix_ptrs+0x15b8/0x515c fs/bcachefs/buckets.c:266 > bch2_trigger_extent+0x71c/0x814 fs/bcachefs/buckets.c:856 > bch2_key_trigger fs/bcachefs/bkey_methods.h:87 [inline] > bch2_gc_mark_key+0x4b4/0xb70 fs/bcachefs/btree_gc.c:634 > bch2_gc_btree fs/bcachefs/btree_gc.c:670 [inline] > bch2_gc_btrees fs/bcachefs/btree_gc.c:729 [inline] > bch2_check_allocations+0x1018/0x48f4 fs/bcachefs/btree_gc.c:1133 > bch2_run_recovery_pass+0xe4/0x1d4 fs/bcachefs/recovery_passes.c:191 > bch2_run_recovery_passes+0x30c/0x73c fs/bcachefs/recovery_passes.c:244 > bch2_fs_recovery+0x32d8/0x55dc fs/bcachefs/recovery.c:861 > bch2_fs_start+0x30c/0x53c fs/bcachefs/super.c:1037 > bch2_fs_get_tree+0x938/0x1030 fs/bcachefs/fs.c:2170 > vfs_get_tree+0x90/0x28c fs/super.c:1814 > do_new_mount+0x278/0x900 fs/namespace.c:3507 > path_mount+0x590/0xe04 fs/namespace.c:3834 > do_mount fs/namespace.c:3847 [inline] > __do_sys_mount fs/namespace.c:4057 [inline] > __se_sys_mount fs/namespace.c:4034 [inline] > __arm64_sys_mount+0x4d4/0x5ac fs/namespace.c:4034 > __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 > el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 > el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 > el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 > > -> #2 (&c->mark_lock){++++}-{0:0}: > percpu_down_read+0x5c/0x2e8 include/linux/percpu-rwsem.h:51 > __bch2_disk_reservation_add+0xc4/0x9f4 fs/bcachefs/buckets.c:1170 > bch2_disk_reservation_add+0x29c/0x4f4 fs/bcachefs/buckets.h:367 > __bch2_folio_reservation_get+0x2dc/0x798 fs/bcachefs/fs-io-pagecache.c:428 > bch2_folio_reservation_get fs/bcachefs/fs-io-pagecache.c:477 [inline] > bch2_page_mkwrite+0xa70/0xe44 fs/bcachefs/fs-io-pagecache.c:637 > do_page_mkwrite+0x140/0x2dc mm/memory.c:3176 > do_shared_fault mm/memory.c:5398 [inline] > do_fault mm/memory.c:5460 [inline] > do_pte_missing mm/memory.c:3979 [inline] > handle_pte_fault+0x1418/0x5890 mm/memory.c:5801 > __handle_mm_fault mm/memory.c:5944 [inline] > handle_mm_fault+0xf0c/0x17b0 mm/memory.c:6112 > faultin_page mm/gup.c:1196 [inline] > __get_user_pages+0x15e4/0x3134 mm/gup.c:1494 > __get_user_pages_locked mm/gup.c:1824 [inline] > __gup_longterm_locked+0xda0/0x12a4 mm/gup.c:2532 > pin_user_pages_remote+0x170/0x24c mm/gup.c:3577 > process_vm_rw_single_vec mm/process_vm_access.c:106 [inline] > process_vm_rw_core mm/process_vm_access.c:216 [inline] > process_vm_rw+0x56c/0x9ac mm/process_vm_access.c:284 > __do_sys_process_vm_writev mm/process_vm_access.c:304 [inline] > __se_sys_process_vm_writev mm/process_vm_access.c:299 [inline] > __arm64_sys_process_vm_writev+0xdc/0xf8 mm/process_vm_access.c:299 > __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 > el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 > el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 > el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 > > -> #1 (sb_pagefaults#3){.+.+}-{0:0}: > percpu_down_read include/linux/percpu-rwsem.h:51 [inline] > __sb_start_write include/linux/fs.h:1725 [inline] > sb_start_pagefault include/linux/fs.h:1890 [inline] > bch2_page_mkwrite+0x280/0xe44 fs/bcachefs/fs-io-pagecache.c:614 > do_page_mkwrite+0x140/0x2dc mm/memory.c:3176 > do_shared_fault mm/memory.c:5398 [inline] > do_fault mm/memory.c:5460 [inline] > do_pte_missing mm/memory.c:3979 [inline] > handle_pte_fault+0x1418/0x5890 mm/memory.c:5801 > __handle_mm_fault mm/memory.c:5944 [inline] > handle_mm_fault+0xf0c/0x17b0 mm/memory.c:6112 > faultin_page mm/gup.c:1196 [inline] > __get_user_pages+0x15e4/0x3134 mm/gup.c:1494 > __get_user_pages_locked mm/gup.c:1824 [inline] > __gup_longterm_locked+0xda0/0x12a4 mm/gup.c:2532 > pin_user_pages_remote+0x170/0x24c mm/gup.c:3577 > process_vm_rw_single_vec mm/process_vm_access.c:106 [inline] > process_vm_rw_core mm/process_vm_access.c:216 [inline] > process_vm_rw+0x56c/0x9ac mm/process_vm_access.c:284 > __do_sys_process_vm_writev mm/process_vm_access.c:304 [inline] > __se_sys_process_vm_writev mm/process_vm_access.c:299 [inline] > __arm64_sys_process_vm_writev+0xdc/0xf8 mm/process_vm_access.c:299 > __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 > el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 > el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 > el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 > > -> #0 (&mm->mmap_lock){++++}-{4:4}: > check_prev_add kernel/locking/lockdep.c:3161 [inline] > check_prevs_add kernel/locking/lockdep.c:3280 [inline] > validate_chain kernel/locking/lockdep.c:3904 [inline] > __lock_acquire+0x34f0/0x7904 kernel/locking/lockdep.c:5226 > lock_acquire+0x23c/0x724 kernel/locking/lockdep.c:5849 > __might_fault+0xc4/0x124 mm/memory.c:6751 > drm_mode_object_get_properties+0x208/0x540 drivers/gpu/drm/drm_mode_object.c:407 > drm_mode_obj_get_properties_ioctl+0x2bc/0x4fc drivers/gpu/drm/drm_mode_object.c:459 > drm_ioctl_kernel+0x26c/0x368 drivers/gpu/drm/drm_ioctl.c:796 > drm_ioctl+0x624/0xb14 drivers/gpu/drm/drm_ioctl.c:893 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:906 [inline] > __se_sys_ioctl fs/ioctl.c:892 [inline] > __arm64_sys_ioctl+0x14c/0x1cc fs/ioctl.c:892 > __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 > el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 > el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 > el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 > > other info that might help us debug this: > > Chain exists of: > &mm->mmap_lock --> crtc_ww_class_acquire --> crtc_ww_class_mutex > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(crtc_ww_class_mutex); > lock(crtc_ww_class_acquire); > lock(crtc_ww_class_mutex); > rlock(&mm->mmap_lock); > > *** DEADLOCK *** > > 2 locks held by syz.3.631/8987: > #0: ffff80009d267910 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_mode_obj_get_properties_ioctl+0x194/0x4fc drivers/gpu/drm/drm_mode_object.c:447 > #1: ffff80009d267938 (crtc_ww_class_mutex){+.+.}-{0:0}, at: drm_mode_obj_get_properties_ioctl+0x194/0x4fc drivers/gpu/drm/drm_mode_object.c:447 > > stack backtrace: > CPU: 1 UID: 0 PID: 8987 Comm: syz.3.631 Not tainted 6.13.0-rc2-syzkaller-g2e7aff49b5da #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 > Call trace: > show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:484 (C) > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120 > dump_stack+0x1c/0x28 lib/dump_stack.c:129 > print_circular_bug+0x154/0x1c0 kernel/locking/lockdep.c:2074 > check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2206 > check_prev_add kernel/locking/lockdep.c:3161 [inline] > check_prevs_add kernel/locking/lockdep.c:3280 [inline] > validate_chain kernel/locking/lockdep.c:3904 [inline] > __lock_acquire+0x34f0/0x7904 kernel/locking/lockdep.c:5226 > lock_acquire+0x23c/0x724 kernel/locking/lockdep.c:5849 > __might_fault+0xc4/0x124 mm/memory.c:6751 > drm_mode_object_get_properties+0x208/0x540 drivers/gpu/drm/drm_mode_object.c:407 > drm_mode_obj_get_properties_ioctl+0x2bc/0x4fc drivers/gpu/drm/drm_mode_object.c:459 > drm_ioctl_kernel+0x26c/0x368 drivers/gpu/drm/drm_ioctl.c:796 > drm_ioctl+0x624/0xb14 drivers/gpu/drm/drm_ioctl.c:893 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:906 [inline] > __se_sys_ioctl fs/ioctl.c:892 [inline] > __arm64_sys_ioctl+0x14c/0x1cc fs/ioctl.c:892 > __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] > invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 > el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 > do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 > el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 > el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 > el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup -- Simona Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch