Hello, syzbot found the following issue on: HEAD commit: 8755ae45a9e8 Add linux-next specific files for 20220819 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=1420bffd080000 kernel config: https://syzkaller.appspot.com/x/.config?x=ead6107a3bbe3c62 dashboard link: https://syzkaller.appspot.com/bug?extid=d011b5a27f77c61c6345 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=170f3023080000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13e56b35080000 Bisection is inconclusive: the first bad commit could be any of: 4fae831b3a71 tty: n_gsm: fix packet re-transmission without open control channel 32dd59f96924 tty: n_gsm: fix race condition in gsmld_write() bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=170af485080000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d011b5a27f77c61c6345@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: trying to register non-static key. The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator. CPU: 0 PID: 3617 Comm: syz-executor272 Not tainted 6.0.0-rc1-next-20220819-syzkaller #0 BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1521 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 3617, name: syz-executor272 preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 INFO: lockdep is turned off. irq event stamp: 4716 hardirqs last enabled at (4715): [<ffffffff898354ff>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] hardirqs last enabled at (4715): [<ffffffff898354ff>] _raw_spin_unlock_irq+0x1f/0x40 kernel/locking/spinlock.c:202 hardirqs last disabled at (4716): [<ffffffff8983532e>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (4716): [<ffffffff8983532e>] _raw_spin_lock_irqsave+0x4e/0x50 kernel/locking/spinlock.c:162 softirqs last enabled at (4594): [<ffffffff81491a33>] invoke_softirq kernel/softirq.c:445 [inline] softirqs last enabled at (4594): [<ffffffff81491a33>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 softirqs last disabled at (4561): [<ffffffff81491a33>] invoke_softirq kernel/softirq.c:445 [inline] softirqs last disabled at (4561): [<ffffffff81491a33>] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 Preemption disabled at: [<0000000000000000>] 0x0 CPU: 0 PID: 3617 Comm: syz-executor272 Not tainted 6.0.0-rc1-next-20220819-syzkaller #0 syz-executor272[3617] cmdline: ./syz-executor2726460068 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:122 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:140 __might_resched.cold+0x222/0x26b kernel/sched/core.c:9896 down_read_killable+0x75/0x490 kernel/locking/rwsem.c:1521 mmap_read_lock_killable include/linux/mmap_lock.h:126 [inline] __access_remote_vm+0xac/0x6f0 mm/memory.c:5461 get_mm_cmdline.part.0+0x217/0x620 fs/proc/base.c:299 get_mm_cmdline fs/proc/base.c:367 [inline] get_task_cmdline_kernel+0x1d9/0x220 fs/proc/base.c:367 dump_stack_print_cmdline.part.0+0x82/0x150 lib/dump_stack.c:61 dump_stack_print_cmdline lib/dump_stack.c:89 [inline] dump_stack_print_info+0x185/0x190 lib/dump_stack.c:97 __dump_stack lib/dump_stack.c:121 [inline] dump_stack_lvl+0xc1/0x134 lib/dump_stack.c:140 assign_lock_key kernel/locking/lockdep.c:979 [inline] register_lock_class+0xf1b/0x1120 kernel/locking/lockdep.c:1292 __lock_acquire+0x109/0x56d0 kernel/locking/lockdep.c:4932 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 gsmld_write+0x5e/0x140 drivers/tty/n_gsm.c:3023 do_tty_write drivers/tty/tty_io.c:1024 [inline] file_tty_write.constprop.0+0x499/0x8f0 drivers/tty/tty_io.c:1095 call_write_iter include/linux/fs.h:2188 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:578 ksys_write+0x127/0x250 fs/read_write.c:631 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+0x63/0xcd RIP: 0033:0x7fc136bf5289 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc832732f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc136bf5289 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fc136bb9070 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000e R11: 0000000000000246 R12: 00007fc136bb9100 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> syz-executor272[3617] cmdline: ./syz-executor2726460068 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:122 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:140 assign_lock_key kernel/locking/lockdep.c:979 [inline] register_lock_class+0xf1b/0x1120 kernel/locking/lockdep.c:1292 __lock_acquire+0x109/0x56d0 kernel/locking/lockdep.c:4932 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 gsmld_write+0x5e/0x140 drivers/tty/n_gsm.c:3023 do_tty_write drivers/tty/tty_io.c:1024 [inline] file_tty_write.constprop.0+0x499/0x8f0 drivers/tty/tty_io.c:1095 call_write_iter include/linux/fs.h:2188 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:578 ksys_write+0x127/0x250 fs/read_write.c:631 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+0x63/0xcd RIP: 0033:0x7fc136bf5289 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
