R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ============================================ WARNING: possible recursive locking detected 6.14.0-rc1-syzkaller-00081-gbb066fe812d6 #0 Not tainted -------------------------------------------- syz.4.1945/12795 is trying to acquire lock: ffffffff8f0c1cc8 (fw_lock){+.+.}-{4:4}, at: assign_fw+0x4e/0x600 drivers/base/firmware_loader/main.c:700 but task is already holding lock: ffffffff8f0c1cc8 (fw_lock){+.+.}-{4:4}, at: device_cache_fw_images drivers/base/firmware_loader/main.c:1548 [inline] ffffffff8f0c1cc8 (fw_lock){+.+.}-{4:4}, at: fw_pm_notify+0x69/0x150 drivers/base/firmware_loader/main.c:1601 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.4.1945/12795: #0: ffffffff8eeb9928 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x420 drivers/char/misc.c:143 #1: ffffffff8e081f48 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x87/0xa0 kernel/power/main.c:56 #2: ffffffff8e0c00d0 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust kernel/notifier.c:344 [inline] #2: ffffffff8e0c00d0 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust+0xa9/0x170 kernel/notifier.c:333 #3: ffffffff8f0c1cc8 (fw_lock){+.+.}-{4:4}, at: device_cache_fw_images drivers/base/firmware_loader/main.c:1548 [inline] #3: ffffffff8f0c1cc8 (fw_lock){+.+.}-{4:4}, at: fw_pm_notify+0x69/0x150 drivers/base/firmware_loader/main.c:1601 #4: ffffffff8f0bc8e8 (dpm_list_mtx){+.+.}-{4:4}, at: device_pm_lock drivers/base/power/main.c:113 [inline] #4: ffffffff8f0bc8e8 (dpm_list_mtx){+.+.}-{4:4}, at: dpm_for_each_dev drivers/base/power/main.c:1986 [inline] #4: ffffffff8f0bc8e8 (dpm_list_mtx){+.+.}-{4:4}, at: dpm_for_each_dev+0x2d/0xb0 drivers/base/power/main.c:1979 stack backtrace: CPU: 3 UID: 0 PID: 12795 Comm: syz.4.1945 Not tainted 6.14.0-rc1-syzkaller-00081-gbb066fe812d6 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_deadlock_bug+0x2e3/0x410 kernel/locking/lockdep.c:3039 check_deadlock kernel/locking/lockdep.c:3091 [inline] validate_chain kernel/locking/lockdep.c:3893 [inline] __lock_acquire+0x2117/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 assign_fw+0x4e/0x600 drivers/base/firmware_loader/main.c:700 _request_firmware+0x993/0x1470 drivers/base/firmware_loader/main.c:944 request_firmware drivers/base/firmware_loader/main.c:992 [inline] cache_firmware drivers/base/firmware_loader/main.c:1330 [inline] __async_dev_cache_fw_image+0xb2/0x340 drivers/base/firmware_loader/main.c:1444 async_schedule_node_domain+0xd1/0x120 kernel/async.c:221 async_schedule_domain include/linux/async.h:72 [inline] dev_cache_fw_image+0x38f/0x490 drivers/base/firmware_loader/main.c:1500 dpm_for_each_dev drivers/base/power/main.c:1988 [inline] dpm_for_each_dev+0x5a/0xb0 drivers/base/power/main.c:1979 device_cache_fw_images drivers/base/firmware_loader/main.c:1550 [inline] fw_pm_notify+0x81/0x150 drivers/base/firmware_loader/main.c:1601 notifier_call_chain+0xb7/0x410 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+0xc9/0x170 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x218/0x2b0 kernel/power/user.c:87 misc_open+0x35a/0x420 drivers/char/misc.c:179 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x735/0x1c40 fs/open.c:955 vfs_open+0x82/0x3f0 fs/open.c:1085 do_open fs/namei.c:3830 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3989 do_filp_open+0x20c/0x470 fs/namei.c:4016 do_sys_openat2+0x17a/0x1e0 fs/open.c:1427 do_sys_open fs/open.c:1442 [inline] __do_compat_sys_openat fs/open.c:1504 [inline] __se_compat_sys_openat fs/open.c:1502 [inline] __ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1502 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 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: 0023:0xf7ff7579 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:00000000f511655c EFLAGS: 00000296 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000800000c0 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- 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