syzbot has found a reproducer for the following issue on: HEAD commit: f0b0d403eabb Merge tag 'kbuild-fixes-v6.6' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14bbe63c680000 kernel config: https://syzkaller.appspot.com/x/.config?x=999148c170811772 dashboard link: https://syzkaller.appspot.com/bug?extid=1fa947e7f09e136925b8 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16148d74680000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13e10762680000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/9067aea1d6b6/disk-f0b0d403.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/5b837ae6375f/vmlinux-f0b0d403.xz kernel image: https://storage.googleapis.com/syzbot-assets/4b1678667256/bzImage-f0b0d403.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1fa947e7f09e136925b8@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor119:9037 blocked for more than 143 seconds. Not tainted 6.6.0-rc1-syzkaller-00240-gf0b0d403eabb #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor119 state:D stack:25872 pid:9037 ppid:5100 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x59f0 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 io_schedule+0xbe/0x130 kernel/sched/core.c:9026 folio_wait_bit_common+0x3d2/0x9b0 mm/filemap.c:1301 folio_lock include/linux/pagemap.h:1042 [inline] clean_bdev_aliases+0x56b/0x610 fs/buffer.c:1725 clean_bdev_bh_alias include/linux/buffer_head.h:219 [inline] __block_write_begin_int+0x8d6/0x1470 fs/buffer.c:2115 iomap_write_begin+0x5be/0x17b0 fs/iomap/buffered-io.c:772 iomap_write_iter fs/iomap/buffered-io.c:907 [inline] iomap_file_buffered_write+0x3d6/0x9a0 fs/iomap/buffered-io.c:968 blkdev_buffered_write block/fops.c:634 [inline] blkdev_write_iter+0x4f5/0xc90 block/fops.c:684 call_write_iter include/linux/fs.h:1985 [inline] do_iter_readv_writev+0x21e/0x3c0 fs/read_write.c:735 do_iter_write+0x17f/0x830 fs/read_write.c:860 vfs_iter_write+0x7a/0xb0 fs/read_write.c:901 iter_file_splice_write+0x698/0xbf0 fs/splice.c:736 do_splice_from fs/splice.c:933 [inline] direct_splice_actor+0x118/0x180 fs/splice.c:1142 splice_direct_to_actor+0x347/0xa30 fs/splice.c:1088 do_splice_direct+0x1af/0x280 fs/splice.c:1194 do_sendfile+0xb88/0x1390 fs/read_write.c:1254 __do_sys_sendfile64 fs/read_write.c:1322 [inline] __se_sys_sendfile64 fs/read_write.c:1308 [inline] __x64_sys_sendfile64+0x1d6/0x220 fs/read_write.c:1308 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f92485ce3b9 RSP: 002b:00007f9248583158 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f924864e3e8 RCX: 00007f92485ce3b9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003 RBP: 00007f924864e3e0 R08: 00007f92485836c0 R09: 0000000000000000 R10: 0100000000000042 R11: 0000000000000246 R12: 00007f924864e3ec R13: 0000000000000016 R14: 00007ffd0b251ce0 R15: 00007ffd0b251dc8 </TASK> Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8cba7860 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6607 2 locks held by getty/4793: #0: ffff888027bb90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900020682f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc5/0x1480 drivers/tty/n_tty.c:2206 3 locks held by syz-executor119/5099: 3 locks held by syz-executor119/5105: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.6.0-rc1-syzkaller-00240-gf0b0d403eabb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfac/0x1230 kernel/hung_task.c:379 kthread+0x33a/0x430 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5097 Comm: syz-executor119 Not tainted 6.6.0-rc1-syzkaller-00240-gf0b0d403eabb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:217 [inline] RIP: 0010:unwind_next_frame+0x25f/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: 83 f4 19 00 00 e8 61 83 4c 00 45 89 ee 48 b8 00 00 00 00 00 fc ff df 4a 8d 3c b5 44 d7 00 90 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 09 84 d2 74 05 e8 db 83 a1 00 RSP: 0018:ffffc9000030f510 EFLAGS: 00000a03 RAX: dffffc0000000000 RBX: ffffc9000030f590 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff813a49af RDI: ffffffff90043a8c RBP: 0000000000000001 R08: 0000000000000004 R09: 000000000000d8d2 R10: 0000000000098000 R11: dffffc0000000000 R12: ffffffff81d8d288 R13: 000000000000d8d2 R14: 000000000000d8d2 R15: ffffc9000030f5c5 FS: 0000555556536480(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556540808 CR3: 000000007a917000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:128 __set_page_owner+0x1f/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2cf/0x340 mm/page_alloc.c:1536 prep_new_page mm/page_alloc.c:1543 [inline] get_page_from_freelist+0xee0/0x2f20 mm/page_alloc.c:3170 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4426 alloc_pages+0x1a9/0x270 mm/mempolicy.c:2298 __get_free_pages+0xc/0x40 mm/page_alloc.c:4477 _pgd_alloc arch/x86/mm/pgtable.c:420 [inline] pgd_alloc+0x28/0x260 arch/x86/mm/pgtable.c:436 mm_alloc_pgd kernel/fork.c:795 [inline] mm_init+0x679/0xf60 kernel/fork.c:1298 dup_mm kernel/fork.c:1683 [inline] copy_mm kernel/fork.c:1735 [inline] copy_process+0x6bf8/0x7400 kernel/fork.c:2501 kernel_clone+0xfd/0x930 kernel/fork.c:2909 __do_sys_clone+0xba/0x100 kernel/fork.c:3052 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f92485cc1a3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd0b251da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f92485cc1a3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffd0b251c44 R10: 0000555556536750 R11: 0000000000000246 R12: 0000000000000001 R13: 431bde82d7b634db R14: 000000000012b3f1 R15: 00007ffd0b251f20 </TASK> --- 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.
