From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f79.google.com (mail-oo1-f79.google.com [209.85.161.79]) (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 8188046EF75 for ; Tue, 4 Aug 2026 15:49:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785858596; cv=none; b=WF8kMKg1jX435XPEvUonN6B0sF6Kx3TnmbZIqpyxqwYVPT6nORM35KgRYUucP2XNw3wo7C+QBCTrOV+eDLoKb+mMFP7ilSCdOkeOjvdmhzRIbaHG2CqMUv/o7pevKNY87eEfq34pX95SU6WybaPpe2wrl/osh6SqtCndduECRmU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785858596; c=relaxed/simple; bh=uovPWBd0SGKEFnKsZBAJzZD9AlNo5Jtze3IGpRMzeak=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=hSDIPYwDMkOD8lS+TSGqpbJQcibCCzZ16YVnT/yVL5wPA5bQxvnMKcrbmWmsLguKccL/hCgTgfiZ9DJhmvMzplgaTNkGuAg/C5I3zfT/FxBC3TfMRfmVPMt5+LzRDOBQgVNOb4etOM+V3bq8OvxJaBsYopmuZvYzV7MeeKzAcCw= 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=209.85.161.79 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-f79.google.com with SMTP id 006d021491bc7-6ab4aec4a14so21956eaf.2 for ; Tue, 04 Aug 2026 08:49:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785858593; x=1786463393; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=lxtXsUiOFnHkFmWf11MjFviaZRoJpPUirT53AJT0fL8=; b=tW4oMmEp0z5hSecSgLSn/NNmBbcJqXbPmDU+hlsINGksQXORnbkmlbo4+l9YOKSgou s4Mmu0GEmc97ADB5GCeUxV8vBsUc42rLGptdmg8LZg4mdq2XxZTa73fNOKC4sGdlyJYA LhvOfT5na11QIeoKRGkEm3GXT/NGLq39FKksTD0nBseiWqhYIk8ZlqAGctLFOGLjJrHm EFwSDd38NDFtg2hpTWCRr9VYIvMDVlO6OWiCrzztczk70lAyoC+l9aJFFMkebTgP3khl NXlpuH5DmviTOgzHJaGOFPSXC0YD4f/XUWMn5Uazgztwxdbw4ZN4toc461fNfz10XYNE WKnA== X-Forwarded-Encrypted: i=1; AHgh+RoL9Zet6ovfBYQOQRd0NC4hB3V/nCOklK7Wx+63KINqnkgRKGpqSCx/F4Z/eRhqCRj5rywQmwQK2LBvkqI=@vger.kernel.org X-Gm-Message-State: AOJu0Yw8Fdq9PJ2vJq2PgZo5/1oQJvLIT0gxVsqqbXIO7addMDzawpSm 0i54W9V1JLnusHQM7NLpMDYyMmguIOl99PD12ze779u4h3eDWTiZgN4n4BCW6KWBQL3lbaCK2Cd 89B2FCYqLWs+wBxTTYjex5Y7EqAdQjZg3doPLj3owzli72EfKITkhCq8rJco= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4a08:b0:6a1:5b63:2ae2 with SMTP id 006d021491bc7-6ae4334a975mr16005047eaf.29.1785858593264; Tue, 04 Aug 2026 08:49:53 -0700 (PDT) Date: Tue, 04 Aug 2026 08:49:53 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a720a21.40259c87.584f4.04bb.GAE@google.com> Subject: [syzbot] [net?] KASAN: slab-use-after-free Read in ipvlan_hard_header (5) 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: 11028ab62899 Merge tag 'probes-fixes-v7.2-rc5' of git://gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10e79499580000 kernel config: https://syzkaller.appspot.com/x/.config?x=4e38b15c29e6a1d9 dashboard link: https://syzkaller.appspot.com/bug?extid=1f9fd0f4b601cf88d6e6 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/ed42f633fbc9/disk-11028ab6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/408a35414ed1/vmlinux-11028ab6.xz kernel image: https://storage.googleapis.com/syzbot-assets/526ce947af17/bzImage-11028ab6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1f9fd0f4b601cf88d6e6@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in dev_hard_header include/linux/netdevice.h:3500 [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 ffff888033c58010 by task syz.1.5338/25164 CPU: 0 UID: 0 PID: 25164 Comm: syz.1.5338 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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:3500 [inline] ipvlan_hard_header+0xa2/0x120 drivers/net/ipvlan/ipvlan_main.c:385 dev_hard_header include/linux/netdevice.h:3503 [inline] tipc_l2_send_msg+0x319/0x400 net/tipc/bearer.c:515 tipc_bearer_xmit_skb+0x2b3/0x400 net/tipc/bearer.c:576 tipc_disc_timeout+0x5f6/0x750 net/tipc/discover.c:340 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+0x225/0x840 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:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x30/0x90 kernel/kcov.c:314 Code: 04 24 65 48 8b 15 b8 07 a6 11 65 8b 0d d9 07 a6 11 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 24 17 00 00 00 74 52 <8b> 8a f8 16 00 00 83 f9 03 75 47 48 8b 8a 00 17 00 00 44 8b 8a fc RSP: 0018:ffffc900064b75d8 EFLAGS: 00000246 RAX: ffffffff8219d998 RBX: ffffea0001693500 RCX: 0000000000000000 RDX: ffff88801de83e00 RSI: 0000000000000133 RDI: 0000000000000001 RBP: ffffc900064b78d0 R08: ffffea0001693507 R09: 1ffffd40002d26a0 R10: dffffc0000000000 R11: fffff940002d26a1 R12: 0000000000000000 R13: 800000005a4d4007 R14: ffff888026990668 R15: 0000000000000133 __zap_vma_range+0x1608/0x4f10 mm/memory.c:-1 unmap_vmas+0x390/0x550 mm/memory.c:2178 exit_mmap+0x293/0x9f0 mm/mmap.c:1300 __mmput+0x118/0x420 kernel/fork.c:1187 exit_mm+0x221/0x2d0 kernel/exit.c:615 do_exit+0x6cd/0x2360 kernel/exit.c:997 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 __do_sys_exit_group kernel/exit.c:1163 [inline] __se_sys_exit_group kernel/exit.c:1161 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1161 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe52a99df99 Code: Unable to access opcode bytes at 0x7fe52a99df6f. RSP: 002b:00007fe52ad4fd88 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe52a99df99 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fe52ad4fdec R08: 0000000000000000 R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000001f6 R13: 00000000000927c0 R14: 0000000000166acd R15: 00007fe52ad4fe40 Allocated by task 16223: 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:5334 [inline] __kvmalloc_node_noprof+0x53f/0x860 mm/slub.c:6905 alloc_netdev_mqs+0xa9/0x12b0 net/core/dev.c:12054 rtnl_create_link+0x321/0xd70 net/core/rtnetlink.c:3721 rtnl_newlink_create+0x25f/0xb00 net/core/rtnetlink.c:3903 __rtnl_newlink net/core/rtnetlink.c:4044 [inline] rtnl_newlink+0x167f/0x1bd0 net/core/rtnetlink.c:4159 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7076 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2252 __do_sys_sendto net/socket.c:2259 [inline] __se_sys_sendto net/socket.c:2255 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2255 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 25158: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 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:2677 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x1c5/0x640 mm/slub.c:6692 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+0x222/0x550 lib/kobject.c:737 netdev_run_todo+0xf56/0x10d0 net/core/dev.c:11755 rtnl_unlock net/core/rtnetlink.c:157 [inline] rtnl_net_unlock include/linux/rtnetlink.h:135 [inline] rtnl_dellink+0x68f/0x810 net/core/rtnetlink.c:3651 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7076 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmsg net/socket.c:2770 [inline] __do_sys_sendmsg net/socket.c:2775 [inline] __se_sys_sendmsg net/socket.c:2773 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888033c58000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 16 bytes inside of freed 4096-byte region [ffff888033c58000, ffff888033c59000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33c58 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888033c59011 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b00a500 dead000000000100 dead000000000122 raw: 0000000000000000 0000200000040004 00000000f5000000 ffff888033c59011 head: 00fff00000000040 ffff88801b00a500 dead000000000100 dead000000000122 head: 0000000000000000 0000200000040004 00000000f5000000 ffff888033c59011 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 5680, tgid 5680 (udevd), ts 133221374293, free_ts 133150703885 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3380 new_slab mm/slub.c:3426 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x2bf/0x6b0 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kvmalloc_node_noprof+0x66b/0x860 mm/slub.c:6905 seq_buf_alloc fs/seq_file.c:39 [inline] seq_read_iter+0x1ea/0xca0 fs/seq_file.c:211 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x595/0xa80 fs/read_write.c:574 ksys_read+0x150/0x270 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 6255 tgid 6255 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5741 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:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_noprof+0x311/0x720 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] __register_sysctl_table+0x6f/0x1370 fs/proc/proc_sysctl.c:1378 __addrconf_sysctl_register+0x31c/0x4b0 net/ipv6/addrconf.c:7366 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7414 ipv6_add_dev+0xd26/0x13a0 net/ipv6/addrconf.c:460 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3685 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline] call_netdevice_notifiers net/core/dev.c:2302 [inline] register_netdevice+0x18a4/0x1eb0 net/core/dev.c:11484 veth_newlink+0x49f/0xb70 drivers/net/veth.c:1863 rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3913 __rtnl_newlink net/core/rtnetlink.c:4044 [inline] rtnl_newlink+0x167f/0x1bd0 net/core/rtnetlink.c:4159 Memory state around the buggy address: ffff888033c57f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888033c57f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888033c58000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888033c58080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888033c58100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 04 24 add $0x24,%al 2: 65 48 8b 15 b8 07 a6 mov %gs:0x11a607b8(%rip),%rdx # 0x11a607c2 9: 11 a: 65 8b 0d d9 07 a6 11 mov %gs:0x11a607d9(%rip),%ecx # 0x11a607ea 11: 81 e1 00 01 ff 00 and $0xff0100,%ecx 17: 74 11 je 0x2a 19: 81 f9 00 01 00 00 cmp $0x100,%ecx 1f: 75 5b jne 0x7c 21: 83 ba 24 17 00 00 00 cmpl $0x0,0x1724(%rdx) 28: 74 52 je 0x7c * 2a: 8b 8a f8 16 00 00 mov 0x16f8(%rdx),%ecx <-- trapping instruction 30: 83 f9 03 cmp $0x3,%ecx 33: 75 47 jne 0x7c 35: 48 8b 8a 00 17 00 00 mov 0x1700(%rdx),%rcx 3c: 44 rex.R 3d: 8b .byte 0x8b 3e: 8a fc mov %ah,%bh --- 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