RBP: 00007f8ea165e090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f8ea3656038 R14: 00007f8ea3655fa0 R15: 00007ffdae8b3838 ============================================ WARNING: possible recursive locking detected syzkaller #0 Tainted: G L -------------------------------------------- syz.7.7244/28597 is trying to acquire lock: ffffffff8de8c5f8 (fw_lock){+.+.}-{4:4}, at: assign_fw+0x52/0x8e0 drivers/base/firmware_loader/main.c:700 but task is already holding lock: ffffffff8de8c5f8 (fw_lock){+.+.}-{4:4}, at: device_cache_fw_images drivers/base/firmware_loader/main.c:1504 [inline] ffffffff8de8c5f8 (fw_lock){+.+.}-{4:4}, at: fw_pm_notify+0x1e8/0x2d0 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.7.7244/28597: #0: ffffffff8ddf3758 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x51/0x350 drivers/char/misc.c:125 #1: ffffffff8d45fa98 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x4a/0x70 kernel/power/main.c:71 #2: ffffffff8d481440 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust+0x65/0x100 kernel/notifier.c:344 #3: ffffffff8de8c5f8 (fw_lock){+.+.}-{4:4}, at: device_cache_fw_images drivers/base/firmware_loader/main.c:1504 [inline] #3: ffffffff8de8c5f8 (fw_lock){+.+.}-{4:4}, at: fw_pm_notify+0x1e8/0x2d0 drivers/base/firmware_loader/main.c:1557 #4: ffffffff8de873b8 (dpm_list_mtx){+.+.}-{4:4}, at: device_pm_lock drivers/base/power/main.c:127 [inline] #4: ffffffff8de873b8 (dpm_list_mtx){+.+.}-{4:4}, at: dpm_for_each_dev+0x29/0xb0 drivers/base/power/main.c:2323 stack backtrace: CPU: 0 UID: 0 PID: 28597 Comm: syz.7.7244 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x2540/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline] mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552 assign_fw+0x52/0x8e0 drivers/base/firmware_loader/main.c:700 _request_firmware+0xf08/0x1680 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+0x7f/0x2d0 drivers/base/firmware_loader/main.c:1400 async_schedule_node_domain+0xde/0x110 kernel/async.c:221 async_schedule_domain include/linux/async.h:72 [inline] dev_cache_fw_image+0x364/0x3e0 drivers/base/firmware_loader/main.c:1456 dpm_for_each_dev+0x56/0xb0 drivers/base/power/main.c:2325 device_cache_fw_images drivers/base/firmware_loader/main.c:1506 [inline] fw_pm_notify+0x200/0x2d0 drivers/base/firmware_loader/main.c:1557 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust+0x85/0x100 kernel/notifier.c:345 pm_notifier_call_chain_robust+0x2c/0x60 kernel/power/main.c:172 snapshot_open+0x139/0x280 kernel/power/user.c:87 misc_open+0x2de/0x350 drivers/char/misc.c:163 chrdev_open+0x4cf/0x5e0 fs/char_dev.c:414 do_dentry_open+0x7d0/0x1270 fs/open.c:962 vfs_open+0x3b/0x350 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x342a/0x3df0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ea33ff749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8ea165e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f8ea3655fa0 RCX: 00007f8ea33ff749 RDX: 0000000000042801 RSI: 00002000000002c0 RDI: ffffffffffffff9c RBP: 00007f8ea165e090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f8ea3656038 R14: 00007f8ea3655fa0 R15: 00007ffdae8b3838 ------------[ cut here ]------------ rtmutex deadlock detected WARNING: kernel/locking/rtmutex.c:1674 at rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674, CPU#0: syz.7.7244/28597 Modules linked in: CPU: 0 UID: 0 PID: 28597 Comm: syz.7.7244 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:rt_mutex_handle_deadlock+0x21/0xb0 kernel/locking/rtmutex.c:1674 Code: 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 86 00 00 00 48 89 f7 e8 a6 39 01 00 48 8d 3d 9f 7c 0a 04 <67> 48 0f b9 3a 4c 8d 3d 00 00 00 00 65 48 8b 1c 25 08 10 b3 91 4c RSP: 0018:ffffc9000581eff0 EFLAGS: 00010286 RAX: 0000000080000000 RBX: ffffc9000581f080 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8b3f57c0 RDI: ffffffff8ede5750 RBP: ffffc9000581f190 R08: ffffffff8edb3477 R09: 1ffffffff1db668e R10: dffffc0000000000 R11: fffffbfff1db668f R12: 1ffff92000b03e0c R13: ffffffff8ad3d599 R14: ffffffff8de8c5a0 R15: dffffc0000000000 FS: 00007f8ea165e6c0(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc79aded1ed CR3: 000000008ef9e000 CR4: 00000000003526f0 Call Trace: __rt_mutex_slowlock kernel/locking/rtmutex.c:1734 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x666/0x6b0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:552 assign_fw+0x52/0x8e0 drivers/base/firmware_loader/main.c:700 _request_firmware+0xf08/0x1680 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+0x7f/0x2d0 drivers/base/firmware_loader/main.c:1400 async_schedule_node_domain+0xde/0x110 kernel/async.c:221 async_schedule_domain include/linux/async.h:72 [inline] dev_cache_fw_image+0x364/0x3e0 drivers/base/firmware_loader/main.c:1456 dpm_for_each_dev+0x56/0xb0 drivers/base/power/main.c:2325 device_cache_fw_images drivers/base/firmware_loader/main.c:1506 [inline] fw_pm_notify+0x200/0x2d0 drivers/base/firmware_loader/main.c:1557 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust+0x85/0x100 kernel/notifier.c:345 pm_notifier_call_chain_robust+0x2c/0x60 kernel/power/main.c:172 snapshot_open+0x139/0x280 kernel/power/user.c:87 misc_open+0x2de/0x350 drivers/char/misc.c:163 chrdev_open+0x4cf/0x5e0 fs/char_dev.c:414 do_dentry_open+0x7d0/0x1270 fs/open.c:962 vfs_open+0x3b/0x350 fs/open.c:1094 do_open fs/namei.c:4628 [inline] path_openat+0x342a/0x3df0 fs/namei.c:4787 do_filp_open+0x1fa/0x410 fs/namei.c:4814 do_sys_openat2+0x121/0x200 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8ea33ff749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8ea165e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f8ea3655fa0 RCX: 00007f8ea33ff749 RDX: 0000000000042801 RSI: 00002000000002c0 RDI: ffffffffffffff9c RBP: 00007f8ea165e090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f8ea3656038 R14: 00007f8ea3655fa0 R15: 00007ffdae8b3838 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 41 57 push %r15 b: 41 56 push %r14 d: 41 55 push %r13 f: 41 54 push %r12 11: 53 push %rbx 12: 83 ff dd cmp $0xffffffdd,%edi 15: 0f 85 86 00 00 00 jne 0xa1 1b: 48 89 f7 mov %rsi,%rdi 1e: e8 a6 39 01 00 call 0x139c9 23: 48 8d 3d 9f 7c 0a 04 lea 0x40a7c9f(%rip),%rdi # 0x40a7cc9 * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 4c 8d 3d 00 00 00 00 lea 0x0(%rip),%r15 # 0x36 36: 65 48 8b 1c 25 08 10 mov %gs:0xffffffff91b31008,%rbx 3d: b3 91 3f: 4c rex.WR