From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f69.google.com (mail-oa1-f69.google.com [209.85.160.69]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E33F91A2 for ; Tue, 5 Dec 2023 08:21:31 -0800 (PST) Received: by mail-oa1-f69.google.com with SMTP id 586e51a60fabf-1fb1c742f0bso3929385fac.0 for ; Tue, 05 Dec 2023 08:21:31 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701793291; x=1702398091; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=vzfIo4UwHjmv9AcSp0c+7fZqXTBTtszlVZK70ogcugI=; b=i3Dl6pDr37MAsETQuXQVAnAc64U6J4ZZUJwXqkMXWDCRUd0Na7CgNC6fRsoJsm9mfd JEj8xuJD/reqqAxtS8hpZVHaNLLa3FSC/EvvpelHxGgATktmXdyEkGs9TDiRGC+HR5q0 49etEwjVHUmuQAkCL6fHWfEeuEwKy2kq/zBNCS1jy1sjn+ccQkEgqEkNakMmuKa/u80Q ry0E37D/+xzZ4pKb66heA9DPsdFmlzOroQeBK2J5ULZltEvVHtofzSC2JirOtdL1ZHd3 G1zKZY2+jwmjAZHB2uYXdA+l1mIXJlUE2HLkRfFIJJWOtseSpN6ZAW4BYzWNe/W9F/P4 imgA== X-Gm-Message-State: AOJu0YxpRBIi11flWWSelS9kKzpElCyNROIsXcy6S0v/uWxB9iOGn/5H o1LC95rtAqBdhCBNeTpf0Y5tDm/RepiLCMmK8pMQEmnboqMn X-Google-Smtp-Source: AGHT+IEBnIl+nc2iDQoJp4qY0EVILgvqwTyNqqBJgobjS6yKzxo52U8yGabACkG0EjlHFhjUVC3gEAIaZNq4IzJFPflAJRGJ5hrd Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6871:283:b0:1fa:e182:4123 with SMTP id i3-20020a056871028300b001fae1824123mr4990580oae.7.1701793291286; Tue, 05 Dec 2023 08:21:31 -0800 (PST) Date: Tue, 05 Dec 2023 08:21:31 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000009bbd76060bc5a03c@google.com> Subject: [syzbot] [net?] KCSAN: data-race in data_push_tail / ip6_addr_string From: syzbot To: davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" X-Spam-Level: ** Hello, syzbot found the following issue on: HEAD commit: d3fa86b1a7b4 Merge tag 'net-6.7-rc3' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11ee5ad0e80000 kernel config: https://syzkaller.appspot.com/x/.config?x=8c1151391aefc0c3 dashboard link: https://syzkaller.appspot.com/bug?extid=28e00a6bab865c9c7d46 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/54d04c4835b4/disk-d3fa86b1.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b978f8963a3b/vmlinux-d3fa86b1.xz kernel image: https://storage.googleapis.com/syzbot-assets/f8c85c8cd6ce/bzImage-d3fa86b1.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+28e00a6bab865c9c7d46@syzkaller.appspotmail.com ext4 filesystem being mounted at /root/syzkaller-testdir4291713644/syzkaller.zakLwE/4472/file1 supports timestamps until 2038-01-19 (0x7fffffff) ================================================================== BUG: KCSAN: data-race in data_push_tail / ip6_addr_string write to 0xffffffff86eb5840 of 1 bytes by task 5346 on cpu 0: string_nocheck lib/vsprintf.c:650 [inline] ip6_addr_string+0x119/0x1a0 lib/vsprintf.c:1469 ip_addr_string+0x15f/0x5d0 lib/vsprintf.c:1591 pointer+0x647/0xd10 lib/vsprintf.c:2444 vsnprintf+0x861/0xe20 lib/vsprintf.c:2823 vscnprintf+0x42/0x80 lib/vsprintf.c:2925 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2124 vprintk_store+0x56f/0x800 kernel/printk/printk.c:2238 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45 _printk+0x7a/0xa0 kernel/printk/printk.c:2328 __ip6_tnl_rcv+0x7ee/0x800 net/ipv6/ip6_tunnel.c:848 ip6_tnl_rcv+0x64/0x80 net/ipv6/ip6_tunnel.c:888 gre_rcv+0x7b5/0x850 ip6_protocol_deliver_rcu+0x92f/0xf30 net/ipv6/ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ip6_input+0xbd/0x1b0 net/ipv6/ip6_input.c:492 ip6_mc_input+0x34a/0x480 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:461 [inline] ip6_rcv_finish+0x1e2/0x2e0 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:314 [inline] ipv6_rcv+0x74/0x150 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5529 [inline] __netif_receive_skb+0x90/0x1b0 net/core/dev.c:5643 netif_receive_skb_internal net/core/dev.c:5729 [inline] netif_receive_skb+0x4a/0x310 net/core/dev.c:5788 tun_rx_batched+0xf0/0x410 drivers/net/tun.c:1555 tun_get_user+0x1d3f/0x2340 drivers/net/tun.c:2002 tun_chr_write_iter+0x18e/0x240 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x48a/0x790 fs/read_write.c:584 ksys_write+0xeb/0x1a0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x42/0x50 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b read to 0xffffffff86eb5840 of 8 bytes by task 5334 on cpu 1: data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline] data_push_tail+0x102/0x430 kernel/printk/printk_ringbuffer.c:675 data_alloc+0xbe/0x2c0 kernel/printk/printk_ringbuffer.c:1046 prb_reserve+0x893/0xbc0 kernel/printk/printk_ringbuffer.c:1555 vprintk_store+0x53e/0x800 kernel/printk/printk.c:2228 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45 _printk+0x7a/0xa0 kernel/printk/printk.c:2328 mnt_warn_timestamp_expiry+0x1bb/0x1f0 fs/namespace.c:2804 do_new_mount_fc fs/namespace.c:3278 [inline] do_new_mount+0x2ee/0x660 fs/namespace.c:3339 path_mount+0x496/0xb30 fs/namespace.c:3664 do_mount fs/namespace.c:3677 [inline] __do_sys_mount fs/namespace.c:3886 [inline] __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3863 __x64_sys_mount+0x67/0x80 fs/namespace.c:3863 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b value changed: 0x000000010000bfe1 -> 0x303a303030303a30 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 5334 Comm: syz-executor.1 Tainted: G W 6.7.0-rc2-syzkaller-00095-gd3fa86b1a7b4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 ================================================================== --- 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@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup