vivid-000: ================= START STATUS ================= vivid-000: Boolean: ====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc3-syzkaller-gb5d2afe8745b #0 Not tainted ------------------------------------------------------ syz-executor367/6243 is trying to acquire lock: ffff0000cf4706e0 (vivid_ctrls:1606:(hdl_user_gen)->_lock){+.+.}-{3:3}, at: v4l2_ctrl_lock include/media/v4l2-ctrls.h:572 [inline] ffff0000cf4706e0 (vivid_ctrls:1606:(hdl_user_gen)->_lock){+.+.}-{3:3}, at: log_ctrl drivers/media/v4l2-core/v4l2-ctrls-core.c:2519 [inline] ffff0000cf4706e0 (vivid_ctrls:1606:(hdl_user_gen)->_lock){+.+.}-{3:3}, at: v4l2_ctrl_handler_log_status+0x284/0x494 drivers/media/v4l2-core/v4l2-ctrls-core.c:2557 but task is already holding lock: ffff0000cf4724e0 (vivid_ctrls:1625:(hdl_vbi_cap)->_lock){+.+.}-{3:3}, at: v4l2_ctrl_handler_log_status+0xe4/0x494 drivers/media/v4l2-core/v4l2-ctrls-core.c:2552 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (vivid_ctrls:1625:(hdl_vbi_cap)->_lock){+.+.}-{3:3}: __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608 __mutex_lock kernel/locking/mutex.c:752 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804 find_ref_lock+0x5c/0x3d4 drivers/media/v4l2-core/v4l2-ctrls-core.c:1648 handler_new_ref+0xf8/0x800 drivers/media/v4l2-core/v4l2-ctrls-core.c:1685 v4l2_ctrl_add_handler+0x190/0x28c drivers/media/v4l2-core/v4l2-ctrls-core.c:2209 vivid_create_controls+0x2378/0x2f84 drivers/media/test-drivers/vivid/vivid-ctrls.c:1951 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1854 [inline] vivid_probe+0x37c8/0x66f8 drivers/media/test-drivers/vivid/vivid-core.c:2018 platform_probe+0x148/0x1c0 drivers/base/platform.c:1404 really_probe+0x394/0x904 drivers/base/dd.c:656 __driver_probe_device+0x194/0x374 drivers/base/dd.c:798 driver_probe_device+0x78/0x330 drivers/base/dd.c:828 __driver_attach+0x3dc/0x648 drivers/base/dd.c:1214 bus_for_each_dev+0x20c/0x298 drivers/base/bus.c:368 driver_attach+0x4c/0x5c drivers/base/dd.c:1231 bus_add_driver+0x2f0/0x58c drivers/base/bus.c:673 driver_register+0x220/0x30c drivers/base/driver.c:246 __platform_driver_register+0x74/0x8c drivers/base/platform.c:867 vivid_init+0x4c/0x8c drivers/media/test-drivers/vivid/vivid-core.c:2145 do_one_initcall+0x254/0x9e4 init/main.c:1238 do_initcall_level+0x154/0x214 init/main.c:1300 do_initcalls+0x58/0xac init/main.c:1316 do_basic_setup+0x8c/0xa0 init/main.c:1335 kernel_init_freeable+0x324/0x478 init/main.c:1548 kernel_init+0x24/0x29c init/main.c:1437 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860 -> #0 (vivid_ctrls:1606:(hdl_user_gen)->_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x248/0x73c kernel/locking/lockdep.c:5754 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608 __mutex_lock kernel/locking/mutex.c:752 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804 v4l2_ctrl_lock include/media/v4l2-ctrls.h:572 [inline] log_ctrl drivers/media/v4l2-core/v4l2-ctrls-core.c:2519 [inline] v4l2_ctrl_handler_log_status+0x284/0x494 drivers/media/v4l2-core/v4l2-ctrls-core.c:2557 v4l2_ctrl_log_status+0xc8/0xe8 drivers/media/v4l2-core/v4l2-ctrls-api.c:1206 vidioc_log_status+0x68/0x124 drivers/media/test-drivers/vivid/vivid-core.c:426 v4l_log_status+0x88/0xf8 drivers/media/v4l2-core/v4l2-ioctl.c:2562 __video_do_ioctl+0x7f4/0xb68 drivers/media/v4l2-core/v4l2-ioctl.c:3049 video_usercopy+0xa00/0x1124 drivers/media/v4l2-core/v4l2-ioctl.c:3390 video_ioctl2+0x3c/0x50 drivers/media/v4l2-core/v4l2-ioctl.c:3444 v4l2_ioctl+0x148/0x18c drivers/media/v4l2-core/v4l2-dev.c:364 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:890 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(vivid_ctrls:1625:(hdl_vbi_cap)->_lock); lock(vivid_ctrls:1606:(hdl_user_gen)->_lock); lock(vivid_ctrls:1625:(hdl_vbi_cap)->_lock); lock(vivid_ctrls:1606:(hdl_user_gen)->_lock); *** DEADLOCK *** 2 locks held by syz-executor367/6243: #0: ffff0000cf475b48 (&dev->mutex#3){+.+.}-{3:3}, at: __video_do_ioctl+0x424/0xb68 drivers/media/v4l2-core/v4l2-ioctl.c:3017 #1: ffff0000cf4724e0 (vivid_ctrls:1625:(hdl_vbi_cap)->_lock){+.+.}-{3:3}, at: v4l2_ctrl_handler_log_status+0xe4/0x494 drivers/media/v4l2-core/v4l2-ctrls-core.c:2552 stack backtrace: CPU: 1 PID: 6243 Comm: syz-executor367 Not tainted 6.9.0-rc3-syzkaller-gb5d2afe8745b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:317 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:324 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:114 dump_stack+0x1c/0x28 lib/dump_stack.c:123 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2060 check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x3384/0x763c kernel/locking/lockdep.c:5137 lock_acquire+0x248/0x73c kernel/locking/lockdep.c:5754 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608 __mutex_lock kernel/locking/mutex.c:752 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804 v4l2_ctrl_lock include/media/v4l2-ctrls.h:572 [inline] log_ctrl drivers/media/v4l2-core/v4l2-ctrls-core.c:2519 [inline] v4l2_ctrl_handler_log_status+0x284/0x494 drivers/media/v4l2-core/v4l2-ctrls-core.c:2557 v4l2_ctrl_log_status+0xc8/0xe8 drivers/media/v4l2-core/v4l2-ctrls-api.c:1206 vidioc_log_status+0x68/0x124 drivers/media/test-drivers/vivid/vivid-core.c:426 v4l_log_status+0x88/0xf8 drivers/media/v4l2-core/v4l2-ioctl.c:2562 __video_do_ioctl+0x7f4/0xb68 drivers/media/v4l2-core/v4l2-ioctl.c:3049 video_usercopy+0xa00/0x1124 drivers/media/v4l2-core/v4l2-ioctl.c:3390 video_ioctl2+0x3c/0x50 drivers/media/v4l2-core/v4l2-ioctl.c:3444 v4l2_ioctl+0x148/0x18c drivers/media/v4l2-core/v4l2-dev.c:364 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:890 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 true vivid-000: Integer 32 Bits: 0 vivid-000: Integer 64 Bits: 0 vivid-000: Menu: Menu Item 3 vivid-000: String: vivid-000: Bitmask: 0x80002000 vivid-000: Integer Menu: 5 vivid-000: U32 1 Element Array: [1] 24 vivid-000: U16 8x16 Matrix: [8][16] 24 vivid-000: U8 2x3x4x5 Array: [2][3][4][5] 24 vivid-000: Area: unknown type 262 vivid-000: Read-Only Integer 32 Bits: 0 vivid-000: U32 Dynamic Array: [100] 50 vivid-000: U8 Pixel Array: [640][368] 128 vivid-000: S32 2 Element Array: [2] 2 vivid-000: S64 5 Element Array: [5] 4 vivid-000: Interlaced VBI Format: false vivid-000: Loop Video: false vivid-000: Wrap Sequence Number: false vivid-000: Wrap Timestamp: None vivid-000: Standard Signal Mode: Current Standard vivid-000: Standard: NTSC-M vivid-000: Percentage of Dropped Buffers: 0 vivid-000: ================== END STATUS ==================