syzbot has found a reproducer for the following issue on: HEAD commit: d206a76d7d27 Linux 6.8-rc6 git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=12eea106180000 kernel config: https://syzkaller.appspot.com/x/.config?x=fad652894fc96962 dashboard link: https://syzkaller.appspot.com/bug?extid=a225ee3df7e7f9372dbe compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1537934a180000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1704b3e2180000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/6fa98109295d/disk-d206a76d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/613b4087d09d/vmlinux-d206a76d.xz kernel image: https://storage.googleapis.com/syzbot-assets/d8cd6514daf9/bzImage-d206a76d.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a225ee3df7e7f9372dbe@xxxxxxxxxxxxxxxxxxxxxxxxx ================================ WARNING: inconsistent lock state 6.8.0-rc6-syzkaller #0 Not tainted -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. syz-executor120/5070 [HC1[1]:SC0[0]:HE0:SE1] takes: ffffffff8ea8cd18 (sync_timeline_list_lock){?.+.}-{2:2}, at: sync_timeline_debug_remove+0x2c/0x150 drivers/dma-buf/sync_debug.c:31 {HARDIRQ-ON-W} state was registered at: trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irq+0x23/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] sync_print_obj drivers/dma-buf/sync_debug.c:118 [inline] sync_info_debugfs_show+0x158/0x4d0 drivers/dma-buf/sync_debug.c:153 seq_read_iter+0x445/0xd60 fs/seq_file.c:230 seq_read+0x3a3/0x4f0 fs/seq_file.c:162 vfs_read+0x204/0xb70 fs/read_write.c:474 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 irq event stamp: 9608 hardirqs last enabled at (9607): [<ffffffff8b71f113>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] hardirqs last enabled at (9607): [<ffffffff8b71f113>] _raw_spin_unlock_irq+0x23/0x50 kernel/locking/spinlock.c:202 hardirqs last disabled at (9608): [<ffffffff8b66faee>] sysvec_irq_work+0xe/0xb0 arch/x86/kernel/irq_work.c:17 softirqs last enabled at (9124): [<ffffffff81592641>] invoke_softirq kernel/softirq.c:427 [inline] softirqs last enabled at (9124): [<ffffffff81592641>] __irq_exit_rcu+0xf1/0x1c0 kernel/softirq.c:632 softirqs last disabled at (9119): [<ffffffff81592641>] invoke_softirq kernel/softirq.c:427 [inline] softirqs last disabled at (9119): [<ffffffff81592641>] __irq_exit_rcu+0xf1/0x1c0 kernel/softirq.c:632 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(sync_timeline_list_lock); <Interrupt> lock(sync_timeline_list_lock); *** DEADLOCK *** no locks held by syz-executor120/5070. stack backtrace: CPU: 0 PID: 5070 Comm: syz-executor120 Not tainted 6.8.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 valid_state+0x13a/0x1c0 kernel/locking/lockdep.c:4013 mark_lock_irq+0xbb/0xc20 kernel/locking/lockdep.c:4216 mark_lock+0x223/0x350 kernel/locking/lockdep.c:4678 mark_usage kernel/locking/lockdep.c:4564 [inline] __lock_acquire+0xb8d/0x1fd0 kernel/locking/lockdep.c:5091 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 sync_timeline_debug_remove+0x2c/0x150 drivers/dma-buf/sync_debug.c:31 sync_timeline_free drivers/dma-buf/sw_sync.c:125 [inline] kref_put include/linux/kref.h:65 [inline] sync_timeline_put drivers/dma-buf/sw_sync.c:137 [inline] timeline_fence_release+0x204/0x250 drivers/dma-buf/sw_sync.c:165 kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:297 [inline] dma_fence_array_release+0x13e/0x240 drivers/dma-buf/dma-fence-array.c:120 irq_work_single+0xe1/0x240 kernel/irq_work.c:221 irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0x18b/0x350 kernel/irq_work.c:261 __sysvec_irq_work+0xa8/0x3e0 arch/x86/kernel/irq_work.c:22 sysvec_irq_work+0x8f/0xb0 arch/x86/kernel/irq_work.c:17 </IRQ> <TASK> asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 da 4b ff f5 48 89 df e8 92 8b 00 f6 e8 ad aa 28 f6 fb bf 01 00 00 00 <e8> 62 5c f2 f5 65 8b 05 e3 cd 91 74 85 c0 74 06 5b c3 cc cc cc cc RSP: 0018:ffffc90003a87b50 EFLAGS: 00000282 RAX: 9ede7a61d4cee000 RBX: ffff888015fb5f30 RCX: ffffffff94485303 RDX: dffffc0000000000 RSI: ffffffff8baab640 RDI: 0000000000000001 RBP: ffff88807f87c63c R08: ffffffff8f8568af R09: 1ffffffff1f0ad15 R10: dffffc0000000000 R11: fffffbfff1f0ad16 R12: ffff888015fb5f20 R13: ffff88807f87c600 R14: dffffc0000000000 R15: ffff888015fb5ee0 spin_unlock_irq include/linux/spinlock.h:401 [inline] sw_sync_debugfs_release+0x14b/0x1d0 drivers/dma-buf/sw_sync.c:359 __fput+0x429/0x8a0 fs/file_table.c:376 task_work_run+0x24e/0x310 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa2c/0x2740 kernel/exit.c:871 do_group_exit+0x206/0x2c0 kernel/exit.c:1020 __do_sys_exit_group kernel/exit.c:1031 [inline] __se_sys_exit_group kernel/exit.c:1029 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1029 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7fb8001b9f39 Code: Unable to access opcode bytes at 0x7fb8001b9f0f. RSP: 002b:00007ffdaf45d478 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000000 ---------------- Code disassembly (best guess): 0: 90 nop 1: f3 0f 1e fa endbr64 5: 53 push %rbx 6: 48 89 fb mov %rdi,%rbx 9: 48 83 c7 18 add $0x18,%rdi d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 12: e8 da 4b ff f5 call 0xf5ff4bf1 17: 48 89 df mov %rbx,%rdi 1a: e8 92 8b 00 f6 call 0xf6008bb1 1f: e8 ad aa 28 f6 call 0xf628aad1 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 62 5c f2 f5 call 0xf5f25c91 <-- trapping instruction 2f: 65 8b 05 e3 cd 91 74 mov %gs:0x7491cde3(%rip),%eax # 0x7491ce19 36: 85 c0 test %eax,%eax 38: 74 06 je 0x40 3a: 5b pop %rbx 3b: c3 ret 3c: cc int3 3d: cc int3 3e: cc int3 3f: cc int3 --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.