> Hello, > > syzbot found the following issue on: > > HEAD commit: 0b58e108042b Add linux-next specific files for 20240703 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=150453b9980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=ed034204f2e40e53 > dashboard link: > https://syzkaller.appspot.com/bug?extid=f1d7fb4f94764243d23e > 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=130e0685980000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16030e6e980000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot- > assets/1d079762feae/disk-0b58e108.raw.xz > vmlinux: https://storage.googleapis.com/syzbot- > assets/e53996c8d8c2/vmlinux-0b58e108.xz > kernel image: https://storage.googleapis.com/syzbot- > assets/a0bf21cdd844/bzImage-0b58e108.xz > > The issue was bisected to: > > commit cbe81a753050f5d43ae62da77ff68dcf1d44f9b3 > Author: Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx> > Date: Mon Jun 24 06:36:16 2024 +0000 > > udmabuf: pin the pages using memfd_pin_folios() API > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13fd687e980000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=1003687e980000 > console output: https://syzkaller.appspot.com/x/log.txt?x=17fd687e980000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+f1d7fb4f94764243d23e@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: cbe81a753050 ("udmabuf: pin the pages using memfd_pin_folios() > API") > > INFO: task syz-executor263:5102 blocked for more than 143 seconds. > Not tainted 6.10.0-rc6-next-20240703-syzkaller #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:syz-executor263 state:D stack:25984 pid:5102 tgid:5102 ppid:5101 > flags:0x00004002 > Call Trace: > <TASK> > context_switch kernel/sched/core.c:5248 [inline] > __schedule+0x1800/0x4a60 kernel/sched/core.c:6600 > __schedule_loop kernel/sched/core.c:6677 [inline] > schedule+0x14b/0x320 kernel/sched/core.c:6692 > io_schedule+0x8d/0x110 kernel/sched/core.c:7477 > folio_wait_bit_common+0x882/0x12b0 mm/filemap.c:1307 > folio_lock include/linux/pagemap.h:1050 [inline] > remove_inode_single_folio fs/hugetlbfs/inode.c:603 [inline] > remove_inode_hugepages+0x508/0x1520 fs/hugetlbfs/inode.c:669 > hugetlbfs_evict_inode+0x23/0x70 fs/hugetlbfs/inode.c:689 > evict+0x2a8/0x630 fs/inode.c:669 > __dentry_kill+0x20d/0x630 fs/dcache.c:603 > dput+0x19f/0x2b0 fs/dcache.c:845 > __fput+0x5f8/0x8a0 fs/file_table.c:430 > task_work_run+0x24f/0x310 kernel/task_work.c:204 > exit_task_work include/linux/task_work.h:39 [inline] > do_exit+0xa2f/0x27f0 kernel/exit.c:882 > do_group_exit+0x207/0x2c0 kernel/exit.c:1031 > __do_sys_exit_group kernel/exit.c:1042 [inline] > __se_sys_exit_group kernel/exit.c:1040 [inline] > __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 > x64_sys_call+0x26e0/0x26e0 > arch/x86/include/generated/asm/syscalls_64.h:232 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f816cea6c09 > RSP: 002b:00007fffc0047be8 EFLAGS: 00000246 ORIG_RAX: > 00000000000000e7 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f816cea6c09 > RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 > RBP: 00007f816cf212b0 R08: ffffffffffffffb8 R09: 0000000000000006 > R10: 0000000000000006 R11: 0000000000000246 R12: 00007f816cf212b0 > R13: 0000000000000000 R14: 00007f816cf21d00 R15: 00007f816ce77e40 > </TASK> > > Showing all locks held in the system: > 1 lock held by khungtaskd/30: > #0: ffffffff8e335860 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire > include/linux/rcupdate.h:333 [inline] > #0: ffffffff8e335860 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock > include/linux/rcupdate.h:845 [inline] > #0: ffffffff8e335860 (rcu_read_lock){....}-{1:2}, at: > debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6704 > 2 locks held by getty/4858: > #0: ffff88802abbc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: > tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 > #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: > n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211 > 1 lock held by syz-executor263/5102: > #0: ffff88801b2e22a8 (&hugetlb_fault_mutex_table[i]){+.+.}-{3:3}, at: > remove_inode_hugepages+0x38e/0x1520 fs/hugetlbfs/inode.c:664 > > ============================================= > > NMI backtrace for cpu 0 > CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.10.0-rc6-next- > 20240703-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 06/07/2024 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 > nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 > nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 > trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] > check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] > watchdog+0xfee/0x1030 kernel/hung_task.c:379 > kthread+0x2f0/0x390 kernel/kthread.c:389 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > </TASK> > Sending NMI from CPU 0 to CPUs 1: > NMI backtrace for cpu 1 > CPU: 1 UID: 0 PID: 953 Comm: kworker/u8:5 Not tainted 6.10.0-rc6-next- > 20240703-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 06/07/2024 > Workqueue: events_unbound toggle_allocation_gate > RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline] > RIP: 0010:write_comp_data kernel/kcov.c:236 [inline] > RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x35/0x90 kernel/kcov.c:290 > Code: 14 25 40 d7 03 00 65 8b 05 50 50 70 7e a9 00 01 ff 00 74 10 a9 00 01 00 > 00 74 5b 83 ba 1c 16 00 00 00 74 52 8b 82 f8 15 00 00 <83> f8 03 75 47 48 8b > 8a 00 16 00 00 44 8b 8a fc 15 00 00 49 c1 e1 > RSP: 0018:ffffc90003f677a8 EFLAGS: 00000246 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: dffffc0000000000 > RDX: ffff888021200000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffffc90003f6794c R08: ffffffff8b8dde5e R09: ffffffff8b8db076 > R10: 0000000000000002 R11: ffff888021200000 R12: 1ffff920007ecf29 > R13: ffffc90003f67920 R14: 1ffff920007ecf2a R15: 0000000000000000 > FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000056483a92b600 CR3: 000000000e132000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <NMI> > </NMI> > <TASK> > insn_get_sib arch/x86/lib/insn.c:447 [inline] > insn_get_displacement+0x2de/0x9a0 arch/x86/lib/insn.c:484 > insn_get_immediate+0x62/0x11f0 arch/x86/lib/insn.c:650 > insn_get_length arch/x86/lib/insn.c:723 [inline] > insn_decode+0x2d6/0x4c0 arch/x86/lib/insn.c:762 > arch_jump_entry_size arch/x86/kernel/jump_label.c:24 [inline] > __jump_label_patch+0xe8/0x490 arch/x86/kernel/jump_label.c:45 > arch_jump_label_transform_queue+0x68/0x100 > arch/x86/kernel/jump_label.c:137 > __jump_label_update+0x177/0x3a0 kernel/jump_label.c:493 > static_key_disable_cpuslocked+0xce/0x1c0 kernel/jump_label.c:240 > static_key_disable+0x1a/0x20 kernel/jump_label.c:248 > toggle_allocation_gate+0x1b8/0x250 mm/kfence/core.c:838 > process_one_work kernel/workqueue.c:3224 [inline] > process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3305 > worker_thread+0x86d/0xd40 kernel/workqueue.c:3383 > kthread+0x2f0/0x390 kernel/kthread.c:389 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > </TASK> > INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.578 > msecs > > > --- > 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 > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > 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. > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup #syz test: https://gitlab.freedesktop.org/Vivek/drm-tip.git syzbot_fix_remove_inode