Hello,
syzbot found the following issue on:
HEAD commit: 1c52283265a4 Merge branch 'akpm' (patches from Andrew) git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1224663fb00000 kernel config: https://syzkaller.appspot.com/x/.config?x=75bc179af0ff0457 dashboard link: https://syzkaller.appspot.com/bug?extid=007bfe0f3330f6e1e7d1 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+007bfe0f3330f6e1e7d1@syzkaller.appspotmail.com
================================ WARNING: inconsistent lock state 5.16.0-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz-executor.2/18360 [HC0[0]:SC0[0]:HE0:SE1] takes: ffffffff8c712cf8 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline] ffffffff8c712cf8 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x2d/0x200 drivers/dma-buf/sync_debug.c:147 {IN-HARDIRQ-W} state was registered at: lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 sync_timeline_debug_remove+0x25/0x190 drivers/dma-buf/sync_debug.c:31 sync_timeline_free drivers/dma-buf/sw_sync.c:104 [inline] kref_put include/linux/kref.h:65 [inline] sync_timeline_put drivers/dma-buf/sw_sync.c:116 [inline] timeline_fence_release+0x263/0x340 drivers/dma-buf/sw_sync.c:144 dma_fence_release+0x2ee/0x590 drivers/dma-buf/dma-fence.c:549 kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] dma_fence_array_release+0x1e4/0x2b0 drivers/dma-buf/dma-fence-array.c:120 dma_fence_release+0x2ee/0x590 drivers/dma-buf/dma-fence.c:549 kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] irq_dma_fence_array_work+0xa5/0xd0 drivers/dma-buf/dma-fence-array.c:52 irq_work_single+0x120/0x270 kernel/irq_work.c:211 irq_work_run_list+0x91/0xc0 kernel/irq_work.c:242 irq_work_run+0x54/0xd0 kernel/irq_work.c:251 __sysvec_irq_work+0x95/0x3d0 arch/x86/kernel/irq_work.c:22 sysvec_irq_work+0x8e/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:664 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:399 [inline] sw_sync_debugfs_release+0x160/0x240 drivers/dma-buf/sw_sync.c:321 __fput+0x286/0x9f0 fs/file_table.c:311 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xb29/0x2a30 kernel/exit.c:806 do_group_exit+0xd2/0x2f0 kernel/exit.c:935 get_signal+0x4b0/0x28c0 kernel/signal.c:2862 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:288 irq event stamp: 124 hardirqs last enabled at (123): [<ffffffff894fd980>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] hardirqs last enabled at (123): [<ffffffff894fd980>] _raw_spin_unlock_irqrestore+0x50/0x70 kernel/locking/spinlock.c:194 hardirqs last disabled at (124): [<ffffffff894fd6e1>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline] hardirqs last disabled at (124): [<ffffffff894fd6e1>] _raw_spin_lock_irq+0x41/0x50 kernel/locking/spinlock.c:170 softirqs last enabled at (116): [<ffffffff81465513>] invoke_softirq kernel/softirq.c:432 [inline] softirqs last enabled at (116): [<ffffffff81465513>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 softirqs last disabled at (97): [<ffffffff81465513>] invoke_softirq kernel/softirq.c:432 [inline] softirqs last disabled at (97): [<ffffffff81465513>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
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 ***
3 locks held by syz-executor.2/18360: #0: ffff88801e30c0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:1034 #1: ffff88807a26dd58 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xdf/0x1280 fs/seq_file.c:182 #2: ffffffff8c712cf8 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:374 [inline] #2: ffffffff8c712cf8 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x2d/0x200 drivers/dma-buf/sync_debug.c:147
stack backtrace: CPU: 0 PID: 18360 Comm: syz-executor.2 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_usage_bug kernel/locking/lockdep.c:203 [inline] valid_state kernel/locking/lockdep.c:3945 [inline] mark_lock_irq kernel/locking/lockdep.c:4148 [inline] mark_lock.cold+0x61/0x8e kernel/locking/lockdep.c:4605 mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4206 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4224 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4292 [inline] lockdep_hardirqs_on_prepare+0x135/0x400 kernel/locking/lockdep.c:4244 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irq+0x1f/0x40 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:399 [inline] sync_print_obj drivers/dma-buf/sync_debug.c:118 [inline] sync_info_debugfs_show+0xeb/0x200 drivers/dma-buf/sync_debug.c:153 seq_read_iter+0x4f5/0x1280 fs/seq_file.c:230 seq_read+0x3e8/0x5c0 fs/seq_file.c:162 vfs_read+0x1b5/0x600 fs/read_write.c:479 ksys_read+0x12d/0x250 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f781fb4b059 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f781e4c0168 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f781fc5df60 RCX: 00007f781fb4b059 RDX: 0000000000000008 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00007f781fba508d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff0ff6575f R14: 00007f781e4c0300 R15: 0000000000022000 </TASK>
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syzbot has found a reproducer for the following issue on:
HEAD commit: 84368d882b96 Merge tag 'soc-fixes-6.1-3' of git://git.kern.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=1670fb65880000 kernel config: https://syzkaller.appspot.com/x/.config?x=6f4e5e9899396248 dashboard link: https://syzkaller.appspot.com/bug?extid=007bfe0f3330f6e1e7d1 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=164376f9880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16cf0965880000
Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/031b6e68785d/disk-84368d88.raw.... vmlinux: https://storage.googleapis.com/syzbot-assets/cff5e66b90e8/vmlinux-84368d88.x... kernel image: https://storage.googleapis.com/syzbot-assets/e75525784a66/bzImage-84368d88.x...
IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+007bfe0f3330f6e1e7d1@syzkaller.appspotmail.com
================================ WARNING: inconsistent lock state 6.1.0-rc5-syzkaller-00144-g84368d882b96 #0 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz-executor333/3645 [HC0[0]:SC0[0]:HE0:SE1] takes: ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline] ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x31/0x200 drivers/dma-buf/sync_debug.c:147 {IN-HARDIRQ-W} state was registered at: lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 sync_timeline_debug_remove+0x29/0x1a0 drivers/dma-buf/sync_debug.c:31 sync_timeline_free drivers/dma-buf/sw_sync.c:104 [inline] kref_put include/linux/kref.h:65 [inline] sync_timeline_put drivers/dma-buf/sw_sync.c:116 [inline] timeline_fence_release+0x267/0x340 drivers/dma-buf/sw_sync.c:144 dma_fence_release+0x14b/0x690 drivers/dma-buf/dma-fence.c:559 kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] dma_fence_array_release+0x1fa/0x2d0 drivers/dma-buf/dma-fence-array.c:120 dma_fence_release+0x14b/0x690 drivers/dma-buf/dma-fence.c:559 kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] irq_dma_fence_array_work+0xa9/0xd0 drivers/dma-buf/dma-fence-array.c:52 irq_work_single+0x124/0x260 kernel/irq_work.c:211 irq_work_run_list kernel/irq_work.c:242 [inline] irq_work_run_list+0x91/0xc0 kernel/irq_work.c:225 irq_work_run+0x58/0xd0 kernel/irq_work.c:251 __sysvec_irq_work+0xce/0x4e0 arch/x86/kernel/irq_work.c:22 sysvec_irq_work+0x92/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:675 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:400 [inline] sw_sync_debugfs_release+0x162/0x240 drivers/dma-buf/sw_sync.c:321 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 ptrace_notify+0x118/0x140 kernel/signal.c:2354 ptrace_report_syscall include/linux/ptrace.h:420 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:482 [inline] syscall_exit_work kernel/entry/common.c:251 [inline] syscall_exit_to_user_mode_prepare+0x129/0x280 kernel/entry/common.c:278 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0xd/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd irq event stamp: 638 hardirqs last enabled at (637): [<ffffffff81cc6530>] ___slab_alloc+0xca0/0x1400 mm/slub.c:3132 hardirqs last disabled at (638): [<ffffffff89f47e95>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline] hardirqs last disabled at (638): [<ffffffff89f47e95>] _raw_spin_lock_irq+0x45/0x50 kernel/locking/spinlock.c:170 softirqs last enabled at (538): [<ffffffff814c1d03>] invoke_softirq kernel/softirq.c:445 [inline] softirqs last enabled at (538): [<ffffffff814c1d03>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 softirqs last disabled at (505): [<ffffffff814c1d03>] invoke_softirq kernel/softirq.c:445 [inline] softirqs last disabled at (505): [<ffffffff814c1d03>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
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 ***
2 locks held by syz-executor333/3645: #0: ffff888021f8c8b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xe3/0x1280 fs/seq_file.c:182 #1: ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline] #1: ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x31/0x200 drivers/dma-buf/sync_debug.c:147
stack backtrace: CPU: 1 PID: 3645 Comm: syz-executor333 Not tainted 6.1.0-rc5-syzkaller-00144-g84368d882b96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_usage_bug kernel/locking/lockdep.c:3963 [inline] valid_state kernel/locking/lockdep.c:3975 [inline] mark_lock_irq kernel/locking/lockdep.c:4178 [inline] mark_lock.part.0.cold+0x18/0xd8 kernel/locking/lockdep.c:4634 mark_lock kernel/locking/lockdep.c:4598 [inline] mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4236 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4254 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4321 [inline] lockdep_hardirqs_on_prepare+0x139/0x410 kernel/locking/lockdep.c:4273 trace_hardirqs_on+0x31/0x160 kernel/trace/trace_preemptirq.c:49 __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:400 [inline] sync_print_obj drivers/dma-buf/sync_debug.c:118 [inline] sync_info_debugfs_show+0xef/0x200 drivers/dma-buf/sync_debug.c:153 seq_read_iter+0x4f9/0x1280 fs/seq_file.c:230 seq_read+0x171/0x210 fs/seq_file.c:162 vfs_read+0x25b/0x930 fs/read_write.c:468 ksys_read+0x12b/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7cb1bbb049 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd52951818 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f7cb1bbb049 RDX: 0000000000002020 RSI: 0000000020002200 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 00007ffd52951290 R11: 0000000000000246 R12: 000000000000e32c R13: 00007ffd5295182c R14: 00007ffd52951840 R15: 00007ffd52951830 </TASK>
On Fri, Nov 18, 2022 at 06:46:38PM -0800, syzbot wrote:
syzbot has found a reproducer for the following issue on:
HEAD commit: 84368d882b96 Merge tag 'soc-fixes-6.1-3' of git://git.kern.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=1670fb65880000 kernel config: https://syzkaller.appspot.com/x/.config?x=6f4e5e9899396248 dashboard link: https://syzkaller.appspot.com/bug?extid=007bfe0f3330f6e1e7d1 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=164376f9880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16cf0965880000
Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/031b6e68785d/disk-84368d88.raw.... vmlinux: https://storage.googleapis.com/syzbot-assets/cff5e66b90e8/vmlinux-84368d88.x... kernel image: https://storage.googleapis.com/syzbot-assets/e75525784a66/bzImage-84368d88.x...
IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+007bfe0f3330f6e1e7d1@syzkaller.appspotmail.com
================================ WARNING: inconsistent lock state 6.1.0-rc5-syzkaller-00144-g84368d882b96 #0 Not tainted
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz-executor333/3645 [HC0[0]:SC0[0]:HE0:SE1] takes: ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline] ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x31/0x200 drivers/dma-buf/sync_debug.c:147 {IN-HARDIRQ-W} state was registered at: lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 sync_timeline_debug_remove+0x29/0x1a0 drivers/dma-buf/sync_debug.c:31 sync_timeline_free drivers/dma-buf/sw_sync.c:104 [inline] kref_put include/linux/kref.h:65 [inline] sync_timeline_put drivers/dma-buf/sw_sync.c:116 [inline] timeline_fence_release+0x267/0x340 drivers/dma-buf/sw_sync.c:144 dma_fence_release+0x14b/0x690 drivers/dma-buf/dma-fence.c:559
Do we need to just generally push all dma_fence_release finalization to an irq work to untangle this mess once and for all? Or is this not just plain old recursion? Christian, any good ideas? -Daniel
kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] dma_fence_array_release+0x1fa/0x2d0 drivers/dma-buf/dma-fence-array.c:120 dma_fence_release+0x14b/0x690 drivers/dma-buf/dma-fence.c:559 kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] irq_dma_fence_array_work+0xa9/0xd0 drivers/dma-buf/dma-fence-array.c:52 irq_work_single+0x124/0x260 kernel/irq_work.c:211 irq_work_run_list kernel/irq_work.c:242 [inline] irq_work_run_list+0x91/0xc0 kernel/irq_work.c:225 irq_work_run+0x58/0xd0 kernel/irq_work.c:251 __sysvec_irq_work+0xce/0x4e0 arch/x86/kernel/irq_work.c:22 sysvec_irq_work+0x92/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:675 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:400 [inline] sw_sync_debugfs_release+0x162/0x240 drivers/dma-buf/sw_sync.c:321 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 ptrace_notify+0x118/0x140 kernel/signal.c:2354 ptrace_report_syscall include/linux/ptrace.h:420 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:482 [inline] syscall_exit_work kernel/entry/common.c:251 [inline] syscall_exit_to_user_mode_prepare+0x129/0x280 kernel/entry/common.c:278 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0xd/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd irq event stamp: 638 hardirqs last enabled at (637): [<ffffffff81cc6530>] ___slab_alloc+0xca0/0x1400 mm/slub.c:3132 hardirqs last disabled at (638): [<ffffffff89f47e95>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline] hardirqs last disabled at (638): [<ffffffff89f47e95>] _raw_spin_lock_irq+0x45/0x50 kernel/locking/spinlock.c:170 softirqs last enabled at (538): [<ffffffff814c1d03>] invoke_softirq kernel/softirq.c:445 [inline] softirqs last enabled at (538): [<ffffffff814c1d03>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 softirqs last disabled at (505): [<ffffffff814c1d03>] invoke_softirq kernel/softirq.c:445 [inline] softirqs last disabled at (505): [<ffffffff814c1d03>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
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 ***
2 locks held by syz-executor333/3645: #0: ffff888021f8c8b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xe3/0x1280 fs/seq_file.c:182 #1: ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline] #1: ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x31/0x200 drivers/dma-buf/sync_debug.c:147
stack backtrace: CPU: 1 PID: 3645 Comm: syz-executor333 Not tainted 6.1.0-rc5-syzkaller-00144-g84368d882b96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace:
<TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_usage_bug kernel/locking/lockdep.c:3963 [inline] valid_state kernel/locking/lockdep.c:3975 [inline] mark_lock_irq kernel/locking/lockdep.c:4178 [inline] mark_lock.part.0.cold+0x18/0xd8 kernel/locking/lockdep.c:4634 mark_lock kernel/locking/lockdep.c:4598 [inline] mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4236 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4254 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4321 [inline] lockdep_hardirqs_on_prepare+0x139/0x410 kernel/locking/lockdep.c:4273 trace_hardirqs_on+0x31/0x160 kernel/trace/trace_preemptirq.c:49 __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:400 [inline] sync_print_obj drivers/dma-buf/sync_debug.c:118 [inline] sync_info_debugfs_show+0xef/0x200 drivers/dma-buf/sync_debug.c:153 seq_read_iter+0x4f9/0x1280 fs/seq_file.c:230 seq_read+0x171/0x210 fs/seq_file.c:162 vfs_read+0x25b/0x930 fs/read_write.c:468 ksys_read+0x12b/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7cb1bbb049 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd52951818 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f7cb1bbb049 RDX: 0000000000002020 RSI: 0000000020002200 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 00007ffd52951290 R11: 0000000000000246 R12: 000000000000e32c R13: 00007ffd5295182c R14: 00007ffd52951840 R15: 00007ffd52951830 </TASK>
Am 22.11.22 um 15:51 schrieb Daniel Vetter:
On Fri, Nov 18, 2022 at 06:46:38PM -0800, syzbot wrote:
syzbot has found a reproducer for the following issue on:
HEAD commit: 84368d882b96 Merge tag 'soc-fixes-6.1-3' of git://git.kern.. git tree: upstream console+strace: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsyzkaller.... kernel config: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsyzkaller.... dashboard link: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsyzkaller.... compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsyzkaller.... C reproducer: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsyzkaller....
Downloadable assets: disk image: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstorage.go... vmlinux: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstorage.go... kernel image: https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstorage.go...
IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+007bfe0f3330f6e1e7d1@syzkaller.appspotmail.com
================================ WARNING: inconsistent lock state 6.1.0-rc5-syzkaller-00144-g84368d882b96 #0 Not tainted
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz-executor333/3645 [HC0[0]:SC0[0]:HE0:SE1] takes: ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline] ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x31/0x200 drivers/dma-buf/sync_debug.c:147 {IN-HARDIRQ-W} state was registered at: lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 sync_timeline_debug_remove+0x29/0x1a0 drivers/dma-buf/sync_debug.c:31 sync_timeline_free drivers/dma-buf/sw_sync.c:104 [inline] kref_put include/linux/kref.h:65 [inline] sync_timeline_put drivers/dma-buf/sw_sync.c:116 [inline] timeline_fence_release+0x267/0x340 drivers/dma-buf/sw_sync.c:144 dma_fence_release+0x14b/0x690 drivers/dma-buf/dma-fence.c:559
Do we need to just generally push all dma_fence_release finalization to an irq work to untangle this mess once and for all? Or is this not just plain old recursion? Christian, any good ideas?
I couldn't even figure out what exactly is going wrong here.
As far as I can see someone just constructed a timeline_fence within a timeline_fence which doesn't sounds valid to me in the first place.
Christian.
-Daniel
kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] dma_fence_array_release+0x1fa/0x2d0 drivers/dma-buf/dma-fence-array.c:120 dma_fence_release+0x14b/0x690 drivers/dma-buf/dma-fence.c:559 kref_put include/linux/kref.h:65 [inline] dma_fence_put include/linux/dma-fence.h:276 [inline] irq_dma_fence_array_work+0xa9/0xd0 drivers/dma-buf/dma-fence-array.c:52 irq_work_single+0x124/0x260 kernel/irq_work.c:211 irq_work_run_list kernel/irq_work.c:242 [inline] irq_work_run_list+0x91/0xc0 kernel/irq_work.c:225 irq_work_run+0x58/0xd0 kernel/irq_work.c:251 __sysvec_irq_work+0xce/0x4e0 arch/x86/kernel/irq_work.c:22 sysvec_irq_work+0x92/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:675 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:400 [inline] sw_sync_debugfs_release+0x162/0x240 drivers/dma-buf/sw_sync.c:321 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16f/0x270 kernel/task_work.c:179 ptrace_notify+0x118/0x140 kernel/signal.c:2354 ptrace_report_syscall include/linux/ptrace.h:420 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:482 [inline] syscall_exit_work kernel/entry/common.c:251 [inline] syscall_exit_to_user_mode_prepare+0x129/0x280 kernel/entry/common.c:278 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0xd/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd irq event stamp: 638 hardirqs last enabled at (637): [<ffffffff81cc6530>] ___slab_alloc+0xca0/0x1400 mm/slub.c:3132 hardirqs last disabled at (638): [<ffffffff89f47e95>] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline] hardirqs last disabled at (638): [<ffffffff89f47e95>] _raw_spin_lock_irq+0x45/0x50 kernel/locking/spinlock.c:170 softirqs last enabled at (538): [<ffffffff814c1d03>] invoke_softirq kernel/softirq.c:445 [inline] softirqs last enabled at (538): [<ffffffff814c1d03>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 softirqs last disabled at (505): [<ffffffff814c1d03>] invoke_softirq kernel/softirq.c:445 [inline] softirqs last disabled at (505): [<ffffffff814c1d03>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
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 ***
2 locks held by syz-executor333/3645: #0: ffff888021f8c8b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xe3/0x1280 fs/seq_file.c:182 #1: ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:375 [inline] #1: ffffffff8d295c38 (sync_timeline_list_lock){?...}-{2:2}, at: sync_info_debugfs_show+0x31/0x200 drivers/dma-buf/sync_debug.c:147
stack backtrace: CPU: 1 PID: 3645 Comm: syz-executor333 Not tainted 6.1.0-rc5-syzkaller-00144-g84368d882b96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace:
<TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_usage_bug kernel/locking/lockdep.c:3963 [inline] valid_state kernel/locking/lockdep.c:3975 [inline] mark_lock_irq kernel/locking/lockdep.c:4178 [inline] mark_lock.part.0.cold+0x18/0xd8 kernel/locking/lockdep.c:4634 mark_lock kernel/locking/lockdep.c:4598 [inline] mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4236 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4254 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4321 [inline] lockdep_hardirqs_on_prepare+0x139/0x410 kernel/locking/lockdep.c:4273 trace_hardirqs_on+0x31/0x160 kernel/trace/trace_preemptirq.c:49 __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:400 [inline] sync_print_obj drivers/dma-buf/sync_debug.c:118 [inline] sync_info_debugfs_show+0xef/0x200 drivers/dma-buf/sync_debug.c:153 seq_read_iter+0x4f9/0x1280 fs/seq_file.c:230 seq_read+0x171/0x210 fs/seq_file.c:162 vfs_read+0x25b/0x930 fs/read_write.c:468 ksys_read+0x12b/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7cb1bbb049 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd52951818 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f7cb1bbb049 RDX: 0000000000002020 RSI: 0000000020002200 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 00007ffd52951290 R11: 0000000000000246 R12: 000000000000e32c R13: 00007ffd5295182c R14: 00007ffd52951840 R15: 00007ffd52951830 </TASK>
syzbot has bisected this issue to:
commit 997acaf6b4b59c6a9c259740312a69ea549cc684 Author: Mark Rutland mark.rutland@arm.com Date: Mon Jan 11 15:37:07 2021 +0000
lockdep: report broken irq restoration
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=115b350d880000 start commit: 84368d882b96 Merge tag 'soc-fixes-6.1-3' of git://git.kern.. git tree: upstream final oops: https://syzkaller.appspot.com/x/report.txt?x=135b350d880000 console output: https://syzkaller.appspot.com/x/log.txt?x=155b350d880000 kernel config: https://syzkaller.appspot.com/x/.config?x=6f4e5e9899396248 dashboard link: https://syzkaller.appspot.com/bug?extid=007bfe0f3330f6e1e7d1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=164376f9880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16cf0965880000
Reported-by: syzbot+007bfe0f3330f6e1e7d1@syzkaller.appspotmail.com Fixes: 997acaf6b4b5 ("lockdep: report broken irq restoration")
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
On Sun, 20 Nov 2022 at 21:51, syzbot syzbot+007bfe0f3330f6e1e7d1@syzkaller.appspotmail.com wrote:
syzbot has bisected this issue to:
commit 997acaf6b4b59c6a9c259740312a69ea549cc684 Author: Mark Rutland mark.rutland@arm.com Date: Mon Jan 11 15:37:07 2021 +0000
lockdep: report broken irq restoration
Ok this looks funny. I'm pretty sure the code in drivers/dma-buf/sw_sync.c around sync_timeline_fence_lock is correct. And we don't do anything that this patch claims to catch, it's all just plain spin_lock_irq and spin_lock_irqsave usage. Only thing that crossed my mind here is that maybe lockdep somehow ends up with two different keys for the same spinlock? I'm really confused ... -Daniel
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=115b350d880000 start commit: 84368d882b96 Merge tag 'soc-fixes-6.1-3' of git://git.kern.. git tree: upstream final oops: https://syzkaller.appspot.com/x/report.txt?x=135b350d880000 console output: https://syzkaller.appspot.com/x/log.txt?x=155b350d880000 kernel config: https://syzkaller.appspot.com/x/.config?x=6f4e5e9899396248 dashboard link: https://syzkaller.appspot.com/bug?extid=007bfe0f3330f6e1e7d1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=164376f9880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16cf0965880000
Reported-by: syzbot+007bfe0f3330f6e1e7d1@syzkaller.appspotmail.com Fixes: 997acaf6b4b5 ("lockdep: report broken irq restoration")
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
linaro-mm-sig@lists.linaro.org
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Christian König -
Daniel Vetter -
syzbot