Hello, syzbot found the following issue on: HEAD commit: f838f8d2 mfd: ab8500-debugfs: Remove extraneous seq_putc git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=163c2447500000 kernel config: https://syzkaller.appspot.com/x/.config?x=7a43a64bad3fdb39 dashboard link: https://syzkaller.appspot.com/bug?extid=77ce5863039267003700 compiler: gcc (GCC) 10.1.0-syz 20200507 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+77ce5863039267003700@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ WARNING: CPU: 2 PID: 22 at mm/page_counter.c:57 page_counter_cancel mm/page_counter.c:57 [inline] WARNING: CPU: 2 PID: 22 at mm/page_counter.c:57 page_counter_cancel+0x56/0x70 mm/page_counter.c:50 Modules linked in: CPU: 2 PID: 22 Comm: ksoftirqd/2 Not tainted 5.10.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 RIP: 0010:page_counter_cancel mm/page_counter.c:57 [inline] RIP: 0010:page_counter_cancel+0x56/0x70 mm/page_counter.c:50 Code: 89 ef 48 89 c3 48 89 c6 e8 37 fd ff ff 31 ff 48 89 de e8 1d cc b8 ff 48 85 db 78 09 5b 5d 41 5c e9 7f c5 b8 ff e8 7a c5 b8 ff <0f> 0b 5b 5d 41 5c e9 6f c5 b8 ff 0f 1f 44 00 00 66 2e 0f 1f 84 00 RSP: 0018:ffffc90000517328 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffffffffffffda RCX: 0000000000000100 RDX: ffff888010c146c0 RSI: ffffffff81b9b926 RDI: 0000000000000003 RBP: ffff8880146bc120 R08: 0000000000000000 R09: ffff8880109d017f R10: ffffffff81b9b913 R11: 0000000000000000 R12: 0000000000000118 R13: 0000000000000200 R14: ffff8880146bc000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020008000 CR3: 000000006b808000 CR4: 0000000000350ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: page_counter_uncharge+0x2e/0x60 mm/page_counter.c:156 drain_stock+0xc9/0x2c0 mm/memcontrol.c:2314 refill_stock+0x132/0x270 mm/memcontrol.c:2363 __sk_mem_reduce_allocated+0x24d/0x550 net/core/sock.c:2711 sk_mem_uncharge include/net/sock.h:1537 [inline] dfrag_uncharge net/mptcp/protocol.c:978 [inline] dfrag_clear+0x45e/0x540 net/mptcp/protocol.c:987 __mptcp_clean_una+0x146/0xc60 net/mptcp/protocol.c:1011 __mptcp_data_acked+0x88/0x290 net/mptcp/protocol.c:2909 mptcp_incoming_options+0x917/0x1d20 net/mptcp/options.c:952 tcp_data_queue+0x1665/0x4b10 net/ipv4/tcp_input.c:4943 tcp_rcv_established+0x841/0x1eb0 net/ipv4/tcp_input.c:5886 tcp_v4_do_rcv+0x5d1/0x870 net/ipv4/tcp_ipv4.c:1676 tcp_v4_rcv+0x2d10/0x3750 net/ipv4/tcp_ipv4.c:2058 ip_protocol_deliver_rcu+0x5c/0x8a0 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x20a/0x370 net/ipv4/ip_input.c:231 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip_local_deliver+0x1b3/0x200 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:447 [inline] ip_rcv_finish+0x1da/0x2f0 net/ipv4/ip_input.c:428 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] ip_rcv+0xaa/0xd0 net/ipv4/ip_input.c:539 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5323 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5437 process_backlog+0x232/0x6c0 net/core/dev.c:6327 napi_poll net/core/dev.c:6805 [inline] net_rx_action+0x461/0xe10 net/core/dev.c:6888 __do_softirq+0x2a5/0x9f7 kernel/softirq.c:343 run_ksoftirqd kernel/softirq.c:650 [inline] run_ksoftirqd+0x2d/0x50 kernel/softirq.c:642 smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:165 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 --- 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.
