From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f77.google.com (mail-oo1-f77.google.com [209.85.161.77]) (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 AB8372836B1 for ; Thu, 15 Jan 2026 20:48:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768510103; cv=none; b=eX4raiw3SslXUfH+A2Dp5kz4m6877GsSwOPwiJni2RDCQ/4hd1srPXRw/wE+7OwYa53bLBQ9xEe/tvrqaGBUFeHmfZfQQHQUTDU00JBgWHCK4lonSwQ89RqcvvHePhnh4rl58dcChiivndgRXIF7KqPU32KuUPJrmu4rA/6treM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768510103; c=relaxed/simple; bh=FxVdzCcElgMBm/fD1EzjuifW7cajsaSmI94Y+vuQ0Qc=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=NxDgYHddeSD6TYh1aTRU8EYp50SZT/ehV8ygn65ODAraJnuEfnxJAWrsFDfu+7GZsfmm6n5XQHMBKhm7CLV7oKh5/U0+MtjsfjK3d+aZYzIsT0QplioN9qnuE7imwn0cPdVb+Qq7LNqVuSsx6P3C9sWpPuFYQLd/JLXOYs2+4fk= 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=209.85.161.77 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-f77.google.com with SMTP id 006d021491bc7-65f6588abf4so3617836eaf.1 for ; Thu, 15 Jan 2026 12:48:21 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768510100; x=1769114900; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=GD/RuU5EoNrflnI+a0Wb0KVlwFSd36TYhdXaFuoMDO8=; b=bnRuAnUm1+gS8iMuZ/If/nET5n+GgRTQuYuYuBwxG3aKL4AHuXh980Ne70HA5JsnKc VfCaRUq7Wktek+F56rEuB0sQTRWBN/jvlIdK4/SZMRbgG1zLHq7OLYRG4iouRHMgo3dI GX0LvrPhAA8Feg/EDTIJ7lSMAj9nqW+lHB8Nl9gJHM9oMTqc5t+e2eyI6dAcP14dJdFr A6KPaIDyXCCizI0UJHe4ob1EhC4gu4XyiwlmSHTOf/fSVkNkaeY+ziiP2qxXI5SXasU6 7yWQWqbcwS4YK4Sis7rDUxcdI21emfBhRvVqzsYUnKhGSM8o2Ev4bXcGFKQpCthSZS1E QYMQ== X-Forwarded-Encrypted: i=1; AJvYcCWPjYsBbEalMs+Ymz0NBoSLsjEC0tdpDRdSw1SafYKcbhdXilUyNleSroRfd73tf/YKJdNKVoc=@vger.kernel.org X-Gm-Message-State: AOJu0YwWzJI2hlyuN4X1lpF1ehKKlsPxLr1uEWxHLJV4WZ0j1Cw/Ny3u sDLgOsfte2Gejcvsy2rbJQRRE4ZyguHctcOeeI/TcVnGtPpqrp8v7kCAGqp+n2PYCA2yLjON50d REP1KzSip4dY8dGNZNSB5m2aCunoMeadYnBrKlLYq6T5nExDGn45QxLxPAUA= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:229d:b0:65b:f0da:31c0 with SMTP id 006d021491bc7-661179faf4bmr532414eaf.55.1768510100572; Thu, 15 Jan 2026 12:48:20 -0800 (PST) Date: Thu, 15 Jan 2026 12:48:20 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69695294.050a0220.58bed.002c.GAE@google.com> Subject: [syzbot] [mm?] KASAN: slab-use-after-free Read in lookup_object_or_alloc (3) From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.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: 79b95d74470d Merge tag 'hid-for-linus-2026010801' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11895f92580000 kernel config: https://syzkaller.appspot.com/x/.config?x=a11e0f726bfb6765 dashboard link: https://syzkaller.appspot.com/bug?extid=62360d745376b40120b5 compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, 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/4d234fb6afe1/disk-79b95d74.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/bb336424f007/vmlinux-79b95d74.xz kernel image: https://storage.googleapis.com/syzbot-assets/e8dee85fdda1/bzImage-79b95d74.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+62360d745376b40120b5@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in timer_is_static_object+0x80/0x90 kernel/time/timer.c:691 Read of size 8 at addr ffff88807e5e8498 by task syz.4.6813/32052 CPU: 1 UID: 0 PID: 32052 Comm: syz.4.6813 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 timer_is_static_object+0x80/0x90 kernel/time/timer.c:691 lookup_object_or_alloc.part.0+0x420/0x590 lib/debugobjects.c:679 lookup_object_or_alloc lib/debugobjects.c:665 [inline] debug_object_activate+0x326/0x4c0 lib/debugobjects.c:820 debug_timer_activate kernel/time/timer.c:793 [inline] __mod_timer+0x814/0xd30 kernel/time/timer.c:1124 add_timer+0x62/0x90 kernel/time/timer.c:1249 call_timer_fn+0x19a/0x5a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x74a/0xae0 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2394 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2404 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 16 fe 1e f6 48 89 df e8 ce 50 1f f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 d5 53 0f f6 65 8b 05 2e b9 37 08 85 c0 74 16 5b RSP: 0018:ffffc90005137760 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff88803400d880 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffffff8dace187 RDI: ffffffff8bf2b380 RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9088b8d7 R11: ffff888046ec54b0 R12: ffff888022b76000 R13: 0000000000000246 R14: ffff88803400d868 R15: ffffc900051378e8 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __skb_try_recv_datagram+0x172/0x4f0 net/core/datagram.c:267 __unix_dgram_recvmsg+0x1bc/0xc30 net/unix/af_unix.c:2576 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2675 sock_recvmsg_nosec net/socket.c:1078 [inline] ____sys_recvmsg+0x5f9/0x6b0 net/socket.c:2810 ___sys_recvmsg+0x114/0x1a0 net/socket.c:2854 do_recvmmsg+0x2fe/0x750 net/socket.c:2949 __sys_recvmmsg net/socket.c:3023 [inline] __do_sys_recvmmsg net/socket.c:3046 [inline] __se_sys_recvmmsg net/socket.c:3039 [inline] __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3039 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdc3eb8f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdc3f959038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fdc3ede6090 RCX: 00007fdc3eb8f749 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007fdc3ec13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdc3ede6128 R14: 00007fdc3ede6090 R15: 00007ffd6a8a5748 Allocated by task 29852: kasan_save_stack+0x33/0x60 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:957 [inline] rose_add_node net/rose/rose_route.c:85 [inline] rose_rt_ioctl+0x880/0x2580 net/rose/rose_route.c:748 rose_ioctl+0x64d/0x7c0 net/rose/af_rose.c:1382 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 32051: kasan_save_stack+0x33/0x60 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6878 rose_neigh_put include/net/rose.h:166 [inline] rose_timer_expiry+0x53f/0x630 net/rose/rose_timer.c:183 call_timer_fn+0x19a/0x5a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x74a/0xae0 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2394 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2404 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 The buggy address belongs to the object at ffff88807e5e8400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 152 bytes inside of freed 512-byte region [ffff88807e5e8400, ffff88807e5e8600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e5e8 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ff26c80 ffffea0000a54f00 dead000000000003 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813ff26c80 ffffea0000a54f00 dead000000000003 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001f97a01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 29165, tgid 29165 (syz-executor), ts 2066518998187, free_ts 1956315063990 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1857 prep_new_page mm/page_alloc.c:1865 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x4fc/0x910 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x14c/0xaa0 net/ipv6/route.c:3820 ip6_route_add.part.0+0x22/0x1d0 net/ipv6/route.c:3949 ip6_route_add+0x45/0x60 net/ipv6/route.c:3946 addrconf_add_mroute+0x1dd/0x350 net/ipv6/addrconf.c:2552 addrconf_add_dev+0x14e/0x1a0 net/ipv6/addrconf.c:2570 inet6_addr_add+0xfe/0x9b0 net/ipv6/addrconf.c:3032 inet6_rtm_newaddr+0x1619/0x1c50 net/ipv6/addrconf.c:5059 page last free pid 27669 tgid 27669 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943 __pagetable_free include/linux/mm.h:3200 [inline] pagetable_free include/linux/mm.h:3224 [inline] pagetable_dtor_free include/linux/mm.h:3328 [inline] __tlb_remove_table include/asm-generic/tlb.h:220 [inline] __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x2b2/0x390 mm/mmu_gather.c:290 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x79c/0x15f0 kernel/rcu/tree.c:2857 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 Memory state around the buggy address: ffff88807e5e8380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807e5e8400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807e5e8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807e5e8500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e5e8580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: f5 cmc 1: 53 push %rbx 2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi 7: 48 89 fb mov %rdi,%rbx a: 48 83 c7 18 add $0x18,%rdi e: e8 16 fe 1e f6 call 0xf61efe29 13: 48 89 df mov %rbx,%rdi 16: e8 ce 50 1f f6 call 0xf61f50e9 1b: f7 c5 00 02 00 00 test $0x200,%ebp 21: 75 23 jne 0x46 23: 9c pushf 24: 58 pop %rax 25: f6 c4 02 test $0x2,%ah 28: 75 37 jne 0x61 * 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2f: e8 d5 53 0f f6 call 0xf60f5409 34: 65 8b 05 2e b9 37 08 mov %gs:0x837b92e(%rip),%eax # 0x837b969 3b: 85 c0 test %eax,%eax 3d: 74 16 je 0x55 3f: 5b pop %rbx --- 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