syzbot has found a reproducer for the following crash on: HEAD commit: e99332e7 gcc-10: mark more functions __init to avoid secti.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1344fb14100000 kernel config: https://syzkaller.appspot.com/x/.config?x=8a96cf498e199d8b dashboard link: https://syzkaller.appspot.com/bug?extid=518c54e255b5031adde4 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=146e45ec100000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=164444a4100000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+518c54e255b5031adde4@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor928:7064 blocked for more than 143 seconds. Not tainted 5.7.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor928 D26720 7064 7053 0x00004004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4158 io_schedule+0x17/0x60 kernel/sched/core.c:5801 wait_on_page_bit_common mm/filemap.c:1153 [inline] wait_on_page_bit mm/filemap.c:1202 [inline] wait_on_page_locked include/linux/pagemap.h:528 [inline] do_read_cache_page+0x648/0x1810 mm/filemap.c:2814 read_mapping_page include/linux/pagemap.h:397 [inline] read_part_sector+0xf6/0x600 block/partitions/core.c:643 adfspart_check_ICS+0x9d/0xc80 block/partitions/acorn.c:360 check_partition block/partitions/core.c:140 [inline] blk_add_partitions+0x474/0xe50 block/partitions/core.c:571 bdev_disk_changed+0x1fb/0x380 fs/block_dev.c:1543 __blkdev_get+0x130c/0x1530 fs/block_dev.c:1681 blkdev_get+0x41/0x2b0 fs/block_dev.c:1748 blkdev_open+0x21d/0x2b0 fs/block_dev.c:1887 do_dentry_open+0x4ba/0x1290 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x405a71 Code: Bad RIP value. RSP: 002b:00007f26eda2b830 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000405a71 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f26eda2b8d0 RBP: 00000000006dbc40 R08: 000000000000000f R09: 00007f26eda2c700 R10: 00007f26eda2c9d0 R11: 0000000000000293 R12: 00000000006dbc4c R13: 00007ffcaf21940f R14: 00007f26eda2c9c0 R15: 20c49ba5e353f7cf Showing all locks held in the system: 1 lock held by khungtaskd/1139: #0: ffffffff899bebc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 2 locks held by in:imklog/6726: #0: ffff88809eddc3f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 #1: ffff8880aa001818 (&parent->list_lock){-.-.}-{2:2}, at: syslog_print kernel/printk/printk.c:1392 [inline] #1: ffff8880aa001818 (&parent->list_lock){-.-.}-{2:2}, at: do_syslog kernel/printk/printk.c:1557 [inline] #1: ffff8880aa001818 (&parent->list_lock){-.-.}-{2:2}, at: do_syslog+0x632/0x16d0 kernel/printk/printk.c:1531 1 lock held by syz-executor928/7064: #0: ffff888088cbb380 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x179/0x1530 fs/block_dev.c:1600 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1139 Comm: khungtaskd Not tainted 5.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
