From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f206.google.com (mail-il1-f206.google.com [209.85.166.206]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CA6E2288CB7 for ; Wed, 25 Jun 2025 09:27:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.206 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750843650; cv=none; b=WbmgPQF5fiEOk5RdQXX7j/wWzgg/WwbULmJq93c0YOjkG6ai3MyiSSJj5gkLFwkCODPiImVBTFK5EKquXHUX6dFpRcGZp0alrGxWZbDys8lBT/9tFIynDUpZdNuCBp53zXauDEIX838rlAI0pO+qvNPapuWAR6c7eNneZaAwSpo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750843650; c=relaxed/simple; bh=Y1GFk7PlOHEcJ2m/1GUfA/nDryFjwkCMIcwJyWxHb6c=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=JLz5iHXKLxJF8uzmyDFHjq0jxJ3hM1WMyKpVnNdb2weT0ojUBPdQxCWVS1Kvy9X8Nr8QWronlis6M+SD0qNjfkl7eYKD6v959BGiz5mEwDWZLnEcogmwqA27RS56oqbSWQZvMOzSAJH4waLdVd/H/pFPp1aFMoUwspY1Co5PCUs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.206 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-il1-f206.google.com with SMTP id e9e14a558f8ab-3ddd5cd020dso129460725ab.0 for ; Wed, 25 Jun 2025 02:27:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750843648; x=1751448448; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=2//FEPqslWZgdnOt/F+B4Qf0RlshSMYBAitdIwd7syY=; b=ZPqvkkfZafxLnL2fLyXaR6G2dOgK4cz7IFWhDJyVoKUbbpr8Ykjn95k5B6/pCcUvkm b974k6iV8/0VXtTw/7LI8XJlYZ6IVszNu0cwZ663RSQGrb5cB9jNaIoZKXC0ur6dLAxQ v9wV06y4WodPIkgMIIlrTaeE3Em7dY07QNBqvgqI/iG41Rq6CtI4GUlLUHGzi78Nmc4U Wf2fAavoxn/YrcXtjNgyfaIOQFweZnzcZmEle4sNBs2M0cEW2hQYgpYk7Kh8/m9dZInh 6o6ohfmydgbwFxHidsBF4YJRbWaByKSsdNrjMPtzyP++Ny8dDk7sfgER81Yqmgko6CTm qSGw== X-Gm-Message-State: AOJu0YzSkx+dKWZfylgoID69Nqwc7b06KFdVSd/lt94JBFkxMXgRKmS0 XiYENMaNB42ajs8/HrVvsbYCa94yevw/s1NT0eC2CjT/VnR2DRA7WNGw9FzqXaxbtfBlAsqyWhL qqVyyEy2lknHv3EHXSwAZNptKPiu1Wy/47VUFziCTZVi8G9Ost+mbuL5tO6Kv0A== X-Google-Smtp-Source: AGHT+IGxHe+HnCO0XkYhoudVoHvfr8xfezkGjrVEFeCPQwTlmGhHMzpRtMLWiiaL9ITshEbgHFEbwZhastD95ONcYl2MatwblD88 Precedence: bulk X-Mailing-List: bridge@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:2181:b0:3dd:d6c2:51fb with SMTP id e9e14a558f8ab-3df329224b9mr25836475ab.10.1750843648019; Wed, 25 Jun 2025 02:27:28 -0700 (PDT) Date: Wed, 25 Jun 2025 02:27:28 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <685bc100.a00a0220.2e5631.00c3.GAE@google.com> Subject: [syzbot] [bridge?] KASAN: slab-use-after-free Read in br_multicast_has_router_adjacent From: syzbot To: bridge@lists.linux.dev, davem@davemloft.net, edumazet@google.com, horms@kernel.org, idosch@nvidia.com, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, razor@blackwall.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 714db279942b CREDITS: Add entry for Shannon Nelson git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=11a59b0c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d11f52d3049c3790 dashboard link: https://syzkaller.appspot.com/bug?extid=f53271ac312b49be132b compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/4af647f77fe2/disk-714db279.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/df9d2caceadd/vmlinux-714db279.xz kernel image: https://storage.googleapis.com/syzbot-assets/f05e60d250ae/bzImage-714db279.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f53271ac312b49be132b@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in br_multicast_has_router_adjacent+0x401/0x4e0 net/bridge/br_multicast.c:5005 Read of size 8 at addr ffff8880584e11b0 by task kworker/u8:7/3505 CPU: 0 UID: 0 PID: 3505 Comm: kworker/u8:7 Not tainted 6.16.0-rc2-syzkaller-00161-g714db279942b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_mcast_mla_update Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 br_multicast_has_router_adjacent+0x401/0x4e0 net/bridge/br_multicast.c:5005 batadv_mcast_mla_rtr_flags_bridge_get net/batman-adv/multicast.c:203 [inline] batadv_mcast_mla_rtr_flags_get net/batman-adv/multicast.c:232 [inline] batadv_mcast_mla_flags_get net/batman-adv/multicast.c:287 [inline] __batadv_mcast_mla_update net/batman-adv/multicast.c:909 [inline] batadv_mcast_mla_update+0x598/0x3670 net/batman-adv/multicast.c:948 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5849: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] new_nbp+0x188/0x440 net/bridge/br_if.c:431 br_add_if+0x28e/0xec0 net/bridge/br_if.c:599 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2946 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3148 rtnl_changelink net/core/rtnetlink.c:3759 [inline] __rtnl_newlink net/core/rtnetlink.c:3918 [inline] rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 __sys_sendto+0x3bd/0x520 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2183 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 23: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22b/0x480 lib/kobject.c:737 rcu_do_batch kernel/rcu/tree.c:2576 [inline] rcu_core+0xca5/0x1710 kernel/rcu/tree.c:2832 handle_softirqs+0x286/0x870 kernel/softirq.c:579 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:164 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3090 [inline] call_rcu+0x142/0x990 kernel/rcu/tree.c:3210 br_del_if+0x146/0x320 net/bridge/br_if.c:739 do_set_master+0x30f/0x6d0 net/core/rtnetlink.c:2930 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3148 rtnl_group_changelink net/core/rtnetlink.c:3773 [inline] __rtnl_newlink net/core/rtnetlink.c:3927 [inline] rtnl_newlink+0x149f/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 ____sys_sendmsg+0x505/0x830 net/socket.c:2566 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880584e1000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 432 bytes inside of freed 1024-byte region [ffff8880584e1000, ffff8880584e1400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880584e6800 pfn:0x584e0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801a441dc0 ffffea0001f4b610 ffffea0001f43610 raw: ffff8880584e6800 000000000010000b 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801a441dc0 ffffea0001f4b610 ffffea0001f43610 head: ffff8880584e6800 000000000010000b 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001613801 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5849, tgid 5849 (syz-executor), ts 81278653145, free_ts 27530166521 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2619 new_slab mm/slub.c:2673 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859 __slab_alloc mm/slub.c:3949 [inline] __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_track_caller_noprof+0x2f8/0x4e0 mm/slub.c:4347 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] nlmsg_new include/net/netlink.h:1041 [inline] br_info_notify+0x105/0x260 net/bridge/br_netlink.c:647 br_add_if+0xbd9/0xec0 net/bridge/br_if.c:690 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2946 do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3148 rtnl_changelink net/core/rtnetlink.c:3759 [inline] __rtnl_newlink net/core/rtnetlink.c:3918 [inline] rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2534 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 __free_pages mm/page_alloc.c:5071 [inline] free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:6927 destroy_args+0x7e/0x5d0 mm/debug_vm_pgtable.c:1009 debug_vm_pgtable+0x412/0x450 mm/debug_vm_pgtable.c:1389 do_one_initcall+0x233/0x820 init/main.c:1274 do_initcall_level+0x137/0x1f0 init/main.c:1336 do_initcalls+0x69/0xd0 init/main.c:1352 kernel_init_freeable+0x3d9/0x570 init/main.c:1584 kernel_init+0x1d/0x1d0 init/main.c:1474 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff8880584e1080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880584e1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880584e1180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880584e1200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880584e1280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- 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