From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f80.google.com (mail-oo1-f80.google.com [209.85.161.80]) (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 A07B6365A13 for ; Fri, 12 Jun 2026 13:56:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.80 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781272588; cv=none; b=sRXV5ExB3VBABwy0R6KokQDAamm5X1UDy6zN05p7xQI+bfUI9DVxpawDtLg0bEZXZqIv+pKQV7iLbbEjBZfumyaTa7mw2HcEWAipAkdLK7a2zbrhNm+cXVA1QFrrHZu5q4rAGGJ4xYb/d5JMbR4cAOF8lrkNpdsQSz9ltcwHOso= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781272588; c=relaxed/simple; bh=dohIcJP/qi9b9gxxHEP5SAOtj2NkNb55hBAIymCiwfM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=bRWjJqPfFxu1oxjmNZzjiq4N5sNs6cREHMqAz+zrffy7cdokiLKsdaqiL991KyOu2CM1z1Kiy8ddjM3prxreGYHTr79APEtmDgvLU7PJY0A/ecl0shsYCqO3PTW1NU0FyFw/hex2cJ4HyJIP6fsl5qG7TPLCIPQzGiAScSIh7uY= 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=209.85.161.80 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-oo1-f80.google.com with SMTP id 006d021491bc7-69e78907328so1527184eaf.2 for ; Fri, 12 Jun 2026 06:56:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781272583; x=1781877383; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=1SW7fXwQmu6JdBSc8q4w3zNut+7p/uyIY+/9nMnflEE=; b=azCoj7/BykqZXqVsmS8QkLk/NT9tdnQ0A/pZLk7Uc6HCCgRMjaUImpS5mZbBLcCY81 PY8m3OUImq5OAXoV4VPOMMN7h+B1zD5+8xdKBekzbcMUzR2N3glLaMqCdl2CXJSrgh/O +dPALcrVPpDNn1mchVUOnIxqVmMtNvAUsjN40qfInL+cPr1u6vl07DCuZb2wy6NdGj11 Ifn/sL/KPqB+pBXj+k3W61uhkua4no/nwG506xUURCrCHCwTH5vO3PuacyyLJ5eehp6A XMHNPd8ADfNB5fUBBpcY/B2T3rYXVNcMr2dcQq7b8m9OesJ9oBESA/cfdBlRYnP5zN5P Irgg== X-Forwarded-Encrypted: i=1; AFNElJ8opCumcAzmg8aAONGjblrIcLmle+UqjqKhpvJHouXIyR2XRIaNqiZU3lr55w/ddScH1NZjGDk=@vger.kernel.org X-Gm-Message-State: AOJu0Ywq0++r+j5/3NDKf+xlGPZMVWztQvG3b2RHMgq4UM3Sbzg16eJP IPjVi/o4BHYkRb9EP8k43u2vAps8/ZqtYvyNeo+KVuHOJTSixdCX19ZWJQLFy60uvd36bUPKeYC s+ZqbKbVCg1evtjUxVcAfQCnDt+NJ6q0R8Sm17LJkJbv3SKYI7TWf/E3uZcA= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:6ae8:b0:69d:5b59:2414 with SMTP id 006d021491bc7-69edc798a18mr1679828eaf.42.1781272583564; Fri, 12 Jun 2026 06:56:23 -0700 (PDT) Date: Fri, 12 Jun 2026 06:56:23 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a2c1007.428ffe26.258b27.015d.GAE@google.com> Subject: [syzbot] [net?] KASAN: slab-use-after-free Read in ipvlan_hard_header (4) From: syzbot To: andrew+netdev@lunn.ch, davem@davemloft.net, 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" Hello, syzbot found the following issue on: HEAD commit: bd3a4795d574 selftests: tls: add test for data loss on sma.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=17536696580000 kernel config: https://syzkaller.appspot.com/x/.config?x=4caf64b1ee83dac0 dashboard link: https://syzkaller.appspot.com/bug?extid=64ec81389cbad56a8c35 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/efddfca22ce3/disk-bd3a4795.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c9f1136a96cb/vmlinux-bd3a4795.xz kernel image: https://storage.googleapis.com/syzbot-assets/a69d66d7068f/bzImage-bd3a4795.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+64ec81389cbad56a8c35@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in dev_hard_header include/linux/netdevice.h:3472 [inline] BUG: KASAN: slab-use-after-free in ipvlan_hard_header+0xa2/0x120 drivers/net/ipvlan/ipvlan_main.c:385 Read of size 8 at addr ffff88807926c010 by task syz-executor/27530 CPU: 0 UID: 0 PID: 27530 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 dev_hard_header include/linux/netdevice.h:3472 [inline] ipvlan_hard_header+0xa2/0x120 drivers/net/ipvlan/ipvlan_main.c:385 dev_hard_header include/linux/netdevice.h:3475 [inline] tipc_l2_send_msg+0x31f/0x400 net/tipc/bearer.c:514 tipc_bearer_xmit_skb+0x2b3/0x400 net/tipc/bearer.c:575 tipc_disc_timeout+0x595/0x6f0 net/tipc/discover.c:338 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xfcf/0x13d0 kernel/smp.c:892 Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 7a 05 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 25 01 0c 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 0a 01 0c RSP: 0018:ffffc900052ef560 EFLAGS: 00000293 RAX: ffffffff81b9ab26 RBX: ffff8880b863c148 RCX: ffff888064b0bd80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900052ef688 R08: ffffffff9030a3f7 R09: 1ffffffff206147e R10: dffffc0000000000 R11: fffffbfff206147f R12: 1ffff110170e8169 R13: dffffc0000000000 R14: ffff8880b8740b48 R15: 0000000000000001 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x5c3/0x10b0 arch/x86/mm/tlb.c:1451 dup_mmap+0x17a2/0x1d90 mm/mmap.c:1905 dup_mm kernel/fork.c:1534 [inline] copy_mm+0x13b/0x4a0 kernel/fork.c:1586 copy_process+0x1f1c/0x4450 kernel/fork.c:2262 kernel_clone+0x284/0x8f0 kernel/fork.c:2723 __do_sys_clone kernel/fork.c:2864 [inline] __se_sys_clone kernel/fork.c:2848 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2848 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f35bc5c5852 Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffc036866c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffc036866c0 RCX: 00007f35bc5c5852 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc0368684c R08: 0000000000000000 R09: 0000000000000001 R10: 00005555868a97d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 00000000000cc36e R15: 00007ffc036868a0 Allocated by task 17236: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kvmalloc_node_noprof+0x528/0x8a0 mm/slub.c:6828 alloc_netdev_mqs+0xa8/0x1210 net/core/dev.c:12026 rtnl_create_link+0x31f/0xd70 net/core/rtnetlink.c:3672 rtnl_newlink_create+0x277/0xb70 net/core/rtnetlink.c:3854 __rtnl_newlink net/core/rtnetlink.c:3995 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4110 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6996 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x672/0x710 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 28096: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6246 [inline] kfree+0x1c5/0x640 mm/slub.c:6561 device_release+0xc4/0x1f0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x228/0x560 lib/kobject.c:737 netdev_run_todo+0xc75/0xde0 net/core/dev.c:11727 rtnl_unlock net/core/rtnetlink.c:157 [inline] rtnl_net_unlock include/linux/rtnetlink.h:135 [inline] rtnl_dellink+0x6a7/0x820 net/core/rtnetlink.c:3602 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6996 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807926c000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 16 bytes inside of freed 4096-byte region [ffff88807926c000, ffff88807926d000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79268 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88802c4dcc01 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fe35500 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800040004 00000000f5000000 ffff88802c4dcc01 head: 00fff00000000040 ffff88813fe35500 dead000000000100 dead000000000122 head: 0000000000000000 0000000800040004 00000000f5000000 ffff88802c4dcc01 head: 00fff00000000003 fffffffffffffe01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5628, tgid 5628 (syz-executor), ts 81469147157, free_ts 54413861367 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x339/0x3d0 mm/slub.c:7251 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5410 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] snmp6_alloc_dev net/ipv6/addrconf.c:362 [inline] ipv6_add_dev+0x6aa/0x13a0 net/ipv6/addrconf.c:413 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3662 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] register_netdevice+0x18c9/0x1ec0 net/core/dev.c:11458 macvlan_common_newlink+0x127c/0x19e0 drivers/net/macvlan.c:1554 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3864 __rtnl_newlink net/core/rtnetlink.c:3995 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4110 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6996 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 page last free pid 5347 tgid 5347 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 __slab_free+0x274/0x2c0 mm/slub.c:5608 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905 alloc_filename fs/namei.c:142 [inline] do_getname+0x2e/0x250 fs/namei.c:182 getname include/linux/fs.h:2526 [inline] getname_maybe_null include/linux/fs.h:2533 [inline] class_filename_maybe_null_constructor include/linux/fs.h:2557 [inline] vfs_fstatat+0x45/0x170 fs/stat.c:368 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807926bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807926bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807926c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807926c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807926c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 79 45 jns 0x47 2: 8b 2e mov (%rsi),%ebp 4: 44 89 ee mov %r13d,%esi 7: 83 e6 01 and $0x1,%esi a: 31 ff xor %edi,%edi c: e8 7a 05 0c 00 call 0xc058b 11: 41 83 e5 01 and $0x1,%r13d 15: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 1c: fc ff df 1f: 75 07 jne 0x28 21: e8 25 01 0c 00 call 0xc014b 26: eb 37 jmp 0x5f 28: f3 90 pause * 2a: 43 0f b6 04 2c movzbl (%r12,%r13,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 75 10 jne 0x43 33: 41 f7 06 01 00 00 00 testl $0x1,(%r14) 3a: 74 1e je 0x5a 3c: e8 .byte 0xe8 3d: 0a 01 or (%rcx),%al 3f: 0c .byte 0xc --- 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