vivid-000: ================= START STATUS ================= vivid-000: Boolean: ====================================================== WARNING: possible circular locking dependency detected 6.9.0-syzkaller-07370-g33e02dc69afb #0 Not tainted ------------------------------------------------------ syz-executor.0/15868 is trying to acquire lock: ffff88801e6006e0 (vivid_ctrls:1606:(hdl_user_gen)->_lock){+.+.}-{3:3}, at: v4l2_ctrl_lock include/media/v4l2-ctrls.h:572 [inline] ffff88801e6006e0 (vivid_ctrls:1606:(hdl_user_gen)->_lock){+.+.}-{3:3}, at: log_ctrl drivers/media/v4l2-core/v4l2-ctrls-core.c:2519 [inline] ffff88801e6006e0 (vivid_ctrls:1606:(hdl_user_gen)->_lock){+.+.}-{3:3}, at: v4l2_ctrl_handler_log_status+0x2c6/0x600 drivers/media/v4l2-core/v4l2-ctrls-core.c:2557 but task is already holding lock: ffff88801e6024b0 (vivid_ctrls:1625:(hdl_vbi_cap)->_lock){+.+.}-{3:3}, at: v4l2_ctrl_handler_log_status+0x109/0x600 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 kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 find_ref_lock drivers/media/v4l2-core/v4l2-ctrls-core.c:1648 [inline] handler_new_ref+0x7c4/0xc60 drivers/media/v4l2-core/v4l2-ctrls-core.c:1685 v4l2_ctrl_add_handler drivers/media/v4l2-core/v4l2-ctrls-core.c:2209 [inline] v4l2_ctrl_add_handler+0x22a/0x310 drivers/media/v4l2-core/v4l2-ctrls-core.c:2183 vivid_create_controls+0x2ad3/0x3910 drivers/media/test-drivers/vivid/vivid-ctrls.c:1951 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1854 [inline] vivid_probe drivers/media/test-drivers/vivid/vivid-core.c:2018 [inline] vivid_probe+0x3bd4/0xa030 drivers/media/test-drivers/vivid/vivid-core.c:2003 platform_probe+0xff/0x1f0 drivers/base/platform.c:1404 call_driver_probe drivers/base/dd.c:578 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:656 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:798 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:828 __driver_attach+0x283/0x580 drivers/base/dd.c:1214 bus_for_each_dev+0x13c/0x1d0 drivers/base/bus.c:368 bus_add_driver+0x2ed/0x640 drivers/base/bus.c:673 driver_register+0x15c/0x4b0 drivers/base/driver.c:246 vivid_init+0x45/0x80 drivers/media/test-drivers/vivid/vivid-core.c:2145 do_one_initcall+0x128/0x630 init/main.c:1245 do_initcall_level init/main.c:1307 [inline] do_initcalls init/main.c:1323 [inline] do_basic_setup init/main.c:1342 [inline] kernel_init_freeable+0x660/0xc50 init/main.c:1556 kernel_init+0x1c/0x2b0 init/main.c:1445 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #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+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 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+0x2c6/0x600 drivers/media/v4l2-core/v4l2-ctrls-core.c:2557 v4l2_ctrl_log_status+0xef/0x130 drivers/media/v4l2-core/v4l2-ctrls-api.c:1206 vidioc_log_status+0x60/0xe0 drivers/media/test-drivers/vivid/vivid-core.c:426 v4l_log_status+0x9e/0x120 drivers/media/v4l2-core/v4l2-ioctl.c:2562 __video_do_ioctl+0xaf9/0xf00 drivers/media/v4l2-core/v4l2-ioctl.c:3049 video_usercopy+0x41a/0x1570 drivers/media/v4l2-core/v4l2-ioctl.c:3390 v4l2_ioctl+0x1c0/0x260 drivers/media/v4l2-core/v4l2-dev.c:364 v4l2_compat_ioctl32+0x21d/0x2c0 drivers/media/v4l2-core/v4l2-compat-ioctl32.c:1200 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1004 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e 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-executor.0/15868: #0: ffff88801e605aa8 (&dev->mutex#3){+.+.}-{3:3}, at: __video_do_ioctl+0x4a8/0xf00 drivers/media/v4l2-core/v4l2-ioctl.c:3017 #1: ffff88801e6024b0 (vivid_ctrls:1625:(hdl_vbi_cap)->_lock){+.+.}-{3:3}, at: v4l2_ctrl_handler_log_status+0x109/0x600 drivers/media/v4l2-core/v4l2-ctrls-core.c:2552 stack backtrace: CPU: 1 PID: 15868 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-07370-g33e02dc69afb #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 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+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 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+0x2c6/0x600 drivers/media/v4l2-core/v4l2-ctrls-core.c:2557 v4l2_ctrl_log_status+0xef/0x130 drivers/media/v4l2-core/v4l2-ctrls-api.c:1206 vidioc_log_status+0x60/0xe0 drivers/media/test-drivers/vivid/vivid-core.c:426 v4l_log_status+0x9e/0x120 drivers/media/v4l2-core/v4l2-ioctl.c:2562 __video_do_ioctl+0xaf9/0xf00 drivers/media/v4l2-core/v4l2-ioctl.c:3049 video_usercopy+0x41a/0x1570 drivers/media/v4l2-core/v4l2-ioctl.c:3390 v4l2_ioctl+0x1c0/0x260 drivers/media/v4l2-core/v4l2-dev.c:364 v4l2_compat_ioctl32+0x21d/0x2c0 drivers/media/v4l2-core/v4l2-compat-ioctl32.c:1200 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1004 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7288579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f5e7a5ac EFLAGS: 00000292 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000005646 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 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: [320][192] 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 ================== ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi