R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ============================================ WARNING: possible recursive locking detected syzkaller #0 Tainted: G L -------------------------------------------- syz.1.5742/30041 is trying to acquire lock: ffffffff8f76ee28 (fw_lock){+.+.}-{4:4}, at: assign_fw+0x4e/0x670 drivers/base/firmware_loader/main.c:700 but task is already holding lock: ffffffff8f76ee28 (fw_lock){+.+.}-{4:4}, at: device_cache_fw_images drivers/base/firmware_loader/main.c:1504 [inline] ffffffff8f76ee28 (fw_lock){+.+.}-{4:4}, at: fw_pm_notify+0x109/0x240 drivers/base/firmware_loader/main.c:1557 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(fw_lock); lock(fw_lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz.1.5742/30041: #0: ffffffff8f528f68 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125 #1: ffffffff8e6a5fa8 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x56/0x70 kernel/power/main.c:71 #2: ffffffff8e6eb270 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust kernel/notifier.c:344 [inline] #2: ffffffff8e6eb270 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust+0xa8/0x160 kernel/notifier.c:333 #3: ffffffff8f76ee28 (fw_lock){+.+.}-{4:4}, at: device_cache_fw_images drivers/base/firmware_loader/main.c:1504 [inline] #3: ffffffff8f76ee28 (fw_lock){+.+.}-{4:4}, at: fw_pm_notify+0x109/0x240 drivers/base/firmware_loader/main.c:1557 #4: ffffffff8f769708 (dpm_list_mtx){+.+.}-{4:4}, at: device_pm_lock drivers/base/power/main.c:127 [inline] #4: ffffffff8f769708 (dpm_list_mtx){+.+.}-{4:4}, at: dpm_for_each_dev drivers/base/power/main.c:2324 [inline] #4: ffffffff8f769708 (dpm_list_mtx){+.+.}-{4:4}, at: dpm_for_each_dev+0x2d/0xb0 drivers/base/power/main.c:2317 stack backtrace: CPU: 2 UID: 0 PID: 30041 Comm: syz.1.5742 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_deadlock_bug.cold+0xbd/0xca kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x12bb/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1a2/0x1b90 kernel/locking/mutex.c:776 assign_fw+0x4e/0x670 drivers/base/firmware_loader/main.c:700 _request_firmware+0x931/0x13c0 drivers/base/firmware_loader/main.c:901 request_firmware drivers/base/firmware_loader/main.c:948 [inline] cache_firmware drivers/base/firmware_loader/main.c:1286 [inline] __async_dev_cache_fw_image+0xb1/0x380 drivers/base/firmware_loader/main.c:1400 async_schedule_node_domain+0xd4/0x120 kernel/async.c:221 async_schedule_domain include/linux/async.h:72 [inline] dev_cache_fw_image+0x38e/0x490 drivers/base/firmware_loader/main.c:1456 dpm_for_each_dev drivers/base/power/main.c:2326 [inline] dpm_for_each_dev+0x5d/0xb0 drivers/base/power/main.c:2317 device_cache_fw_images drivers/base/firmware_loader/main.c:1506 [inline] fw_pm_notify+0x121/0x240 drivers/base/firmware_loader/main.c:1557 notifier_call_chain+0x99/0x420 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline] blocking_notifier_call_chain_robust+0xc8/0x160 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:172 snapshot_open+0x213/0x2a0 kernel/power/user.c:87 misc_open+0x26d/0x450 drivers/char/misc.c:163 chrdev_open+0x234/0x6a0 fs/char_dev.c:411 do_dentry_open+0x6d8/0x1660 fs/open.c:949 vfs_open+0x82/0x3f0 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4830 do_file_open+0x20e/0x430 fs/namei.c:4859 do_sys_openat2+0x10d/0x1e0 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_compat_sys_openat fs/open.c:1434 [inline] __se_compat_sys_openat fs/open.c:1432 [inline] __ia32_compat_sys_openat+0x12d/0x210 fs/open.c:1432 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe3/0x8c0 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf700ef6c Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 58 b8 77 00 00 00 cd 80 0f 0b 8d b6 00 00 00 00 b8 ad RSP: 002b:00000000f53bb50c EFLAGS: 00000292 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000800002c0 RDX: 0000000000042801 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: d2 74 05 c1 shlb %cl,-0x3f(%rbp,%rax,1) 4: e8 0c 89 02 8b call 0x8b028915 9: 5d pop %rbp a: fc cld b: 31 c0 xor %eax,%eax d: c9 leave e: c3 ret f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 0f 1f 00 nopl (%rax) 21: 51 push %rcx 22: 52 push %rdx 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 58 pop %rax 2f: b8 77 00 00 00 mov $0x77,%eax 34: cd 80 int $0x80 36: 0f 0b ud2 38: 8d b6 00 00 00 00 lea 0x0(%rsi),%esi 3e: b8 .byte 0xb8 3f: ad lods %ds:(%rsi),%eax