Hello, syzbot found the following issue on: HEAD commit: 88b06399 Merge tag 'for-5.13-rc1-part2-tag' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13c0d265d00000 kernel config: https://syzkaller.appspot.com/x/.config?x=807beec6b4d66bf1 dashboard link: https://syzkaller.appspot.com/bug?extid=5a864149dd970b546223 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10436223d00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1715208bd00000 The issue was bisected to: commit 91f245d5d5de0802428a478802ec051f7de2f5d6 Author: Jens Axboe <axboe@xxxxxxxxx> Date: Tue Feb 9 20:48:50 2021 +0000 io_uring: enable kmemcg account for io_uring requests bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=144fbb23d00000 final oops: https://syzkaller.appspot.com/x/report.txt?x=164fbb23d00000 console output: https://syzkaller.appspot.com/x/log.txt?x=124fbb23d00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+5a864149dd970b546223@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 91f245d5d5de ("io_uring: enable kmemcg account for io_uring requests") ------------[ cut here ]------------ WARNING: CPU: 1 PID: 8784 at fs/io_uring.c:1499 req_ref_sub_and_test fs/io_uring.c:1499 [inline] WARNING: CPU: 1 PID: 8784 at fs/io_uring.c:1499 io_put_req_deferred fs/io_uring.c:2191 [inline] WARNING: CPU: 1 PID: 8784 at fs/io_uring.c:1499 io_link_timeout_fn+0x96c/0xb20 fs/io_uring.c:6369 Modules linked in: CPU: 1 PID: 8784 Comm: systemd-cgroups Not tainted 5.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:req_ref_sub_and_test fs/io_uring.c:1499 [inline] RIP: 0010:io_put_req_deferred fs/io_uring.c:2191 [inline] RIP: 0010:io_link_timeout_fn+0x96c/0xb20 fs/io_uring.c:6369 Code: 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 84 f9 fd ff ff e8 ae ff da ff e9 ef fd ff ff e8 f4 03 96 ff <0f> 0b e9 6a fc ff ff e8 e8 03 96 ff 4c 89 ef e8 10 96 ff ff 48 8d RSP: 0018:ffffc90000dc0d70 EFLAGS: 00010046 RAX: 0000000080010001 RBX: ffff88802c080c80 RCX: 0000000000000000 RDX: ffff8880373954c0 RSI: ffffffff81dece4c RDI: 0000000000000003 RBP: ffff88802c080cdc R08: 000000000000007f R09: ffff88802c080cdf R10: ffffffff81decab3 R11: 0000000000000000 R12: 000000000000007f R13: 0000000000000000 R14: ffff88802c15e000 R15: ffff88802c15e680 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6ba37daab4 CR3: 0000000015bdf000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 </IRQ> asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:647 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:166 [inline] RIP: 0010:unwind_next_frame+0x308/0x1ce0 arch/x86/kernel/unwind_orc.c:443 Code: 48 8d 3c 40 4c 8d 8c 3f cc 27 3d 8e 83 c2 01 49 81 f9 a4 0c dd 8e 0f 83 f3 10 00 00 89 d7 48 8d 3c 7f 48 8d bc 3f cc 27 3d 8e <48> 81 ff a4 0c dd 8e 0f 87 d8 10 00 00 48 8d 3c 85 3c 8f d2 8d 29 RSP: 0018:ffffc9000918f6a8 EFLAGS: 00000293 RAX: 000000000002bff1 RBX: 1ffff92001231edd RCX: 000000000002bff1 RDX: 000000000002bffb RSI: 000000000000b9cd RDI: ffffffff8e4da7ae RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8e4da772 R10: fffff52001231efb R11: 0000000000084087 R12: ffffc9000918f7c8 R13: ffffc9000918f7b5 R14: ffffc9000918f780 R15: ffffffff81b9cd7f arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 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+0xfb/0x130 mm/kasan/common.c:368 kasan_slab_free include/linux/kasan.h:212 [inline] slab_free_hook mm/slub.c:1581 [inline] slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1606 slab_free mm/slub.c:3166 [inline] kmem_cache_free+0x8a/0x740 mm/slub.c:3182 anon_vma_chain_free mm/rmap.c:141 [inline] unlink_anon_vmas+0x472/0x860 mm/rmap.c:439 free_pgtables+0xe2/0x2f0 mm/memory.c:413 exit_mmap+0x2b7/0x590 mm/mmap.c:3209 __mmput+0x122/0x470 kernel/fork.c:1096 mmput+0x58/0x60 kernel/fork.c:1117 exit_mm kernel/exit.c:502 [inline] do_exit+0xb0a/0x2a60 kernel/exit.c:813 do_group_exit+0x125/0x310 kernel/exit.c:923 __do_sys_exit_group kernel/exit.c:934 [inline] __se_sys_exit_group kernel/exit.c:932 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:932 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f6ba4eb3618 Code: Unable to access opcode bytes at RIP 0x7f6ba4eb35ee. RSP: 002b:00007ffd8038caf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6ba4eb3618 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00007f6ba51908e0 R08: 00000000000000e7 R09: fffffffffffffee8 R10: 00007f6ba336e158 R11: 0000000000000246 R12: 00007f6ba51908e0 R13: 00007f6ba5195c20 R14: 0000000000000000 R15: 0000000000000000 --- 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 syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches