On 2/25/21 9:47 AM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 577c2835 Add linux-next specific files for 20210224 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=1586e0dad00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=e9bb3d369b3bf49 > dashboard link: https://syzkaller.appspot.com/bug?extid=7bf785eedca35ca05501 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16609646d00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1529c5a8d00000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+7bf785eedca35ca05501@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KASAN: use-after-free in __lock_acquire+0x3e6f/0x54c0 kernel/locking/lockdep.c:4770 > Read of size 8 at addr ffff888030dc08d0 by task syz-executor199/9383 > > CPU: 1 PID: 9383 Comm: syz-executor199 Not tainted 5.11.0-next-20210224-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:79 [inline] > dump_stack+0xfa/0x151 lib/dump_stack.c:120 > print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232 > __kasan_report mm/kasan/report.c:399 [inline] > kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 > __lock_acquire+0x3e6f/0x54c0 kernel/locking/lockdep.c:4770 > lock_acquire kernel/locking/lockdep.c:5510 [inline] > lock_acquire+0x1ab/0x730 kernel/locking/lockdep.c:5475 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 > try_to_wake_up+0x98/0x14a0 kernel/sched/core.c:3347 > io_wq_destroy+0x74/0x3d0 fs/io-wq.c:1013 > __io_uring_files_cancel+0x195/0x230 fs/io_uring.c:8810 > io_uring_files_cancel include/linux/io_uring.h:47 [inline] > do_exit+0x299/0x2a60 kernel/exit.c:780 > do_group_exit+0x125/0x310 kernel/exit.c:922 > __do_sys_exit_group kernel/exit.c:933 [inline] > __se_sys_exit_group kernel/exit.c:931 [inline] > __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931 > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xae > RIP: 0033:0x43e989 > Code: 00 49 c7 c0 c0 ff ff ff be e7 00 00 00 ba 3c 00 00 00 eb 12 0f 1f 44 00 00 89 d0 0f 05 48 3d 00 f0 ff ff 77 1c f4 89 f0 0f 05 <48> 3d 00 f0 ff ff 76 e7 f7 d8 64 41 89 00 eb df 0f 1f 80 00 00 00 > RSP: 002b:00007ffe3a2de828 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 00000000004b02f0 RCX: 000000000043e989 > RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 > RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000010000000 > R10: 0000000000008011 R11: 0000000000000246 R12: 00000000004b02f0 > R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 > > Allocated by task 9383: > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 > kasan_set_track mm/kasan/common.c:46 [inline] > set_alloc_info mm/kasan/common.c:427 [inline] > __kasan_slab_alloc+0x75/0x90 mm/kasan/common.c:460 > kasan_slab_alloc include/linux/kasan.h:223 [inline] > slab_post_alloc_hook mm/slab.h:516 [inline] > slab_alloc_node mm/slub.c:2907 [inline] > kmem_cache_alloc_node+0x16d/0x3c0 mm/slub.c:2943 > alloc_task_struct_node kernel/fork.c:170 [inline] > dup_task_struct kernel/fork.c:860 [inline] > copy_process+0x613/0x6fd0 kernel/fork.c:1940 > kernel_clone+0xe7/0xab0 kernel/fork.c:2462 > io_wq_fork_thread+0xa7/0xe0 fs/io-wq.c:601 > io_wq_create+0x81c/0xab0 fs/io-wq.c:985 > io_init_wq_offload fs/io_uring.c:7779 [inline] > io_uring_alloc_task_context+0x185/0x510 fs/io_uring.c:7798 > io_uring_add_task_file+0x261/0x350 fs/io_uring.c:8737 > io_uring_install_fd fs/io_uring.c:9336 [inline] > io_uring_create fs/io_uring.c:9487 [inline] > io_uring_setup+0x14c7/0x2c20 fs/io_uring.c:9526 > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > Freed by task 12: > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 > kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 > kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 > ____kasan_slab_free mm/kasan/common.c:360 [inline] > ____kasan_slab_free mm/kasan/common.c:325 [inline] > __kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367 > kasan_slab_free include/linux/kasan.h:199 [inline] > slab_free_hook mm/slub.c:1562 [inline] > slab_free_freelist_hook+0x72/0x1b0 mm/slub.c:1600 > slab_free mm/slub.c:3161 [inline] > kmem_cache_free+0x8b/0x730 mm/slub.c:3177 > __put_task_struct+0x267/0x3f0 kernel/fork.c:742 > put_task_struct include/linux/sched/task.h:111 [inline] > delayed_put_task_struct+0x1f6/0x340 kernel/exit.c:173 > rcu_do_batch kernel/rcu/tree.c:2559 [inline] > rcu_core+0x722/0x1280 kernel/rcu/tree.c:2794 > __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 > > Last potentially related work creation: > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 > kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345 > __call_rcu kernel/rcu/tree.c:3039 [inline] > call_rcu+0xb1/0x700 kernel/rcu/tree.c:3114 > put_task_struct_rcu_user+0x7f/0xb0 kernel/exit.c:179 > context_switch kernel/sched/core.c:4327 [inline] > __schedule+0x914/0x21a0 kernel/sched/core.c:5075 > preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:5235 > preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 > __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] > _raw_spin_unlock_irqrestore+0x46/0x50 kernel/locking/spinlock.c:191 > io_wq_manager+0x13c/0x5b0 fs/io-wq.c:715 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > The buggy address belongs to the object at ffff888030dc0000 > which belongs to the cache task_struct of size 6912 > The buggy address is located 2256 bytes inside of > 6912-byte region [ffff888030dc0000, ffff888030dc1b00) > The buggy address belongs to the page: > page:00000000deb921bd refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30dc0 > head:00000000deb921bd order:3 compound_mapcount:0 compound_pincount:0 > flags: 0xfff00000010200(slab|head) > raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888140004000 > raw: 0000000000000000 0000000080040004 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff888030dc0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff888030dc0800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> ffff888030dc0880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff888030dc0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff888030dc0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== Same that trinity reported, that one already got fixed and merged into the parent. #syz invalid -- Jens Axboe
