Hello, syzbot found the following issue on: HEAD commit: 75b607fab38d Merge tag 'sched_ext-for-6.12-rc2-fixes' of g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15e49f9f980000 kernel config: https://syzkaller.appspot.com/x/.config?x=667b897270c8ae6 dashboard link: https://syzkaller.appspot.com/bug?extid=e7baeb70aa00c22ed45e compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/a7759a7b0126/disk-75b607fa.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/734e9758ae9d/vmlinux-75b607fa.xz kernel image: https://storage.googleapis.com/syzbot-assets/e23bee69aa18/bzImage-75b607fa.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e7baeb70aa00c22ed45e@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz.2.8721:28280 blocked for more than 143 seconds. Not tainted 6.12.0-rc2-syzkaller-00058-g75b607fab38d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.8721 state:D stack:24848 pid:28280 tgid:28278 ppid:21973 flags:0x00000004 Call Trace: <TASK> context_switch kernel/sched/core.c:5322 [inline] __schedule+0xef5/0x5750 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1671 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg net/socket.c:744 [inline] ____sys_sendmsg+0x9ae/0xb40 net/socket.c:2602 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2656 __sys_sendmsg+0x117/0x1f0 net/socket.c:2685 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5c35f7dff9 RSP: 002b:00007f5c36d61038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f5c36136058 RCX: 00007f5c35f7dff9 RDX: 0000000000008004 RSI: 0000000020000140 RDI: 0000000000000004 RBP: 00007f5c35ff0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5c36136058 R15: 00007ffcc9b7fe28 </TASK> Showing all locks held in the system: 2 locks held by kworker/u8:1/12: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1212/0x1b30 kernel/workqueue.c:3204 #1: ffffc90000117d80 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205 1 lock held by khungtaskd/30: #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 3 locks held by kworker/u8:9/3046: 2 locks held by getty/4992: #0: ffff88814ba810a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5223: 2 locks held by syz-executor/18087: #0: ffff888066cea0e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff888066cea0e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888066cea0e0 (&type->s_umount_key#49){++++}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e1d1868 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625 1 lock held by syz.1.7378/23757: 2 locks held by syz.2.8721/28279: #0: ffffffff8fb61250 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e1d1868 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1964 2 locks held by syz.2.8721/28280: #0: ffffffff8fb61250 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e1d1868 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1671 2 locks held by syz-executor/28836: #0: ffff8880543960e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880543960e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880543960e0 (&type->s_umount_key#49){++++}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e1d1868 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625 2 locks held by syz.0.8904/29170: #0: ffff88807b2260e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807b2260e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807b2260e0 (&type->s_umount_key#49){++++}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e1d1868 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625 2 locks held by syz-executor/29233: #0: ffff88807bb580e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807bb580e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807bb580e0 (&type->s_umount_key#49){++++}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e1d1868 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625 2 locks held by syz.2.8947/29381: #0: ffffffff8fb61250 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e1d1868 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_threads_set_doit+0x694/0xbe0 fs/nfsd/nfsctl.c:1671 2 locks held by syz-executor/29390: #0: ffff88802e63a0e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88802e63a0e0 (&type->s_umount_key#49){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88802e63a0e0 (&type->s_umount_key#49){++++}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:505 #1: ffffffff8e1d1868 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:625 2 locks held by syz-executor/29649: 1 lock held by syz.1.9007/29775: 2 locks held by syz.1.9027/29961: 1 lock held by syz.0.9047/30028: 1 lock held by syz.2.9046/30029: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller-00058-g75b607fab38d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 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+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 23757 Comm: syz.1.7378 Not tainted 6.12.0-rc2-syzkaller-00058-g75b607fab38d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:kernel_fpu_begin_mask+0x17b/0x270 arch/x86/kernel/fpu/core.c:443 Code: 01 31 ff 89 de e8 45 b6 59 00 85 db 0f 85 ce 00 00 00 e8 f8 b3 59 00 48 b8 00 00 00 00 00 fc ff df 48 c7 44 05 00 00 00 00 00 <48> 8b 44 24 58 65 48 2b 04 25 28 00 00 00 0f 85 c6 00 00 00 48 83 RSP: 0018:ffffc9000ac3f3d8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc9000ac4d000 RDX: 0000000000040000 RSI: ffffffff813304c8 RDI: 0000000000000005 RBP: 1ffff92001587e7b R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000001000 R14: 0000000000001000 R15: ffffc9000ac3f500 FS: 00007faf7f5ea6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbfabe67d60 CR3: 000000002859c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> kernel_fpu_begin arch/x86/include/asm/fpu/api.h:42 [inline] _sha256_update arch/x86/crypto/sha256_ssse3_glue.c:73 [inline] _sha256_update+0xb7/0x220 arch/x86/crypto/sha256_ssse3_glue.c:58 ima_calc_file_hash_tfm+0x302/0x3e0 security/integrity/ima/ima_crypto.c:491 ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline] ima_calc_file_hash+0x1ba/0x490 security/integrity/ima/ima_crypto.c:568 ima_collect_measurement+0x8a7/0xa10 security/integrity/ima/ima_api.c:293 process_measurement+0x1271/0x2370 security/integrity/ima/ima_main.c:372 ima_file_mmap+0x1b1/0x1d0 security/integrity/ima/ima_main.c:462 security_mmap_file+0x8bd/0x990 security/security.c:2977 vm_mmap_pgoff+0xdb/0x360 mm/util.c:584 ksys_mmap_pgoff+0x1c8/0x5c0 mm/mmap.c:542 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:79 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:79 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faf7e77dff9 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:00007faf7f5ea038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007faf7e935f80 RCX: 00007faf7e77dff9 RDX: 00004000000000df RSI: 0000002000000004 RDI: 0000000000000002 RBP: 00007faf7e7f0296 R08: 0000000000000404 R09: 0000300000000000 R10: 0000000000040eb2 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007faf7e935f80 R15: 00007fffb2184568 </TASK> --- 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. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title 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
