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 26A8C212548 for ; Fri, 12 Dec 2025 06:07:27 +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=1765519650; cv=none; b=MwVELuI3mt8MU984OTCdnyzd3PL56eDu83IXsDeX6dluKDZGTS34e2nOhc8w4TE7GgcgaMVXjEjS12feNx6vsnAJx+B48NXUmdZWwiYxolCF7fEDRAKcb6hQMwBMvqo9gy6jNa6jPg6KRIzFH6FXkN+1a28XC3QgJfAUYGehSE0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765519650; c=relaxed/simple; bh=2DmD7rDLlFdQlsJp39OTKnDTUtBlYdf5BFZSGpt81LU=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=QXnxQGs8cjBfeClULzgunXm27j0h9aiKXMTy7OXGMHvsj0AGm/nuuTmwy9KKtYt4fuXVWYB1WHibpJFzjFcFcICWOrAMOhEIYY/Z7atvgM1vuskvGUlo/yAmLcTwh/h7TkAFlT9PA1DtU2VtzozhbAGSsaPcofKRdySAJbfmVqM= 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 006d021491bc7-65744e10b91so741786eaf.0 for ; Thu, 11 Dec 2025 22:07:27 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1765519647; x=1766124447; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Jxj8zadq0D6afyYYIxbbvwEgXef9f5DSCoSvIE68SIo=; b=exCe6lmCKp8XjidvayC664dfGnyHeUWbelGfzH6jqlt06B5k/PzWuAoM8iueNLOek1 c68Z3nteFficYYWaU0/mwm/dPZrzRLymc6HQUX1KUrBJ8pYPe2Al6sDnp5IhZjdSJ0Ea jDCcHRs/wMEBX/t7FhMLDIcV2nGf3uWXsI81mhKggbPVzADBJsOZI3B493MiMlINwRVI nqJTQT3gyn5Y+j9uiY57+ODWEA4JKjKzD8OCfblejb9PcN+w7NN7fesFpcEQDAIxfFQf WRvcgWBrkpVCpb52ti4czuUv6Xmu/PVpC4CMHlsoV+9Mbzppn/XmIefsu+PJ+z/Paf5/ Rm2Q== X-Forwarded-Encrypted: i=1; AJvYcCUq6Qvmy+seopPOi1mHhVT9I4RyPU5NB7jB/uNADt2psjtVXHn6ljAthoZemqD+Tt5niW+DsCB6vh7e0cU=@vger.kernel.org X-Gm-Message-State: AOJu0YzwrYer91H0NBfGBXYD6S/BPnbAA67gvjWUVbBd2WLxC0t8h0Pb oX0h5ZIWacEGMTFI1Xe07Km6WK78wsxV8OftxCohWL9mo2a3iaTldqZAHEgLJa+FB+vcrwlRCi3 75VZXXnrI128EXfDd/yXaGJNf8UU2dQgue3oiw7WRbJFJ529awMMpaxeWVtE= X-Google-Smtp-Source: AGHT+IGB6UMOOBD8Ib/8FipeM3z8JwY4giLhvQkNezqUC/bMmR7Fko98/oxPf5uGtSsMxowIBN/sPjK6JJJlTTzuUGM49BaZ1bDK Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:210b:b0:651:c8cb:f662 with SMTP id 006d021491bc7-65b450e9c98mr448738eaf.1.1765519647289; Thu, 11 Dec 2025 22:07:27 -0800 (PST) Date: Thu, 11 Dec 2025 22:07:27 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <693bb11f.050a0220.4004e.04ee.GAE@google.com> Subject: [syzbot] [kernfs?] KASAN: slab-use-after-free Read in kernfs_new_node From: syzbot To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tj@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 67a454e6b1c6 Merge tag 'memblock-6.19-rc1' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11438ec2580000 kernel config: https://syzkaller.appspot.com/x/.config?x=8750900a7c493a0b dashboard link: https://syzkaller.appspot.com/bug?extid=9af8471255ac36e34fd4 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/ce07389f93b8/disk-67a454e6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/31b4e74f868a/vmlinux-67a454e6.xz kernel image: https://storage.googleapis.com/syzbot-assets/9a4287e94d18/bzImage-67a454e6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9af8471255ac36e34fd4@syzkaller.appspotmail.com usb 3-1: Direct firmware load for ueagle-atm/eagleII.fw failed with error -2 usb 3-1: Falling back to sysfs fallback for: ueagle-atm/eagleII.fw ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: slab-use-after-free in kernfs_get fs/kernfs/dir.c:537 [inline] BUG: KASAN: slab-use-after-free in kernfs_new_node+0x120/0x210 fs/kernfs/dir.c:719 Read of size 4 at addr ffff88806684a960 by task kworker/1:10/8396 CPU: 1 UID: 0 PID: 8396 Comm: kworker/1:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events request_firmware_work_func Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] kernfs_get fs/kernfs/dir.c:537 [inline] kernfs_new_node+0x120/0x210 fs/kernfs/dir.c:719 kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1086 sysfs_create_dir_ns+0x123/0x280 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x6b1/0xcd0 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_add+0x155/0x220 lib/kobject.c:426 class_dir_create_and_add drivers/base/core.c:3232 [inline] get_device_parent+0x31d/0x3a0 drivers/base/core.c:3283 device_add+0x2e1/0xb80 drivers/base/core.c:3613 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:86 [inline] fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:162 [inline] firmware_fallback_sysfs+0x2e4/0xa40 drivers/base/firmware_loader/fallback.c:238 _request_firmware+0xfa4/0x1680 drivers/base/firmware_loader/main.c:898 request_firmware_work_func+0xaf/0x1c0 drivers/base/firmware_loader/main.c:1150 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 44: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5265 __kernfs_new_node+0xdc/0x900 fs/kernfs/dir.c:637 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:716 kernfs_create_dir_ns+0x44/0x130 fs/kernfs/dir.c:1086 sysfs_create_dir_ns+0x123/0x280 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x6b1/0xcd0 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_add+0x155/0x220 lib/kobject.c:426 device_add+0x408/0xb80 drivers/base/core.c:3627 usb_new_device+0xa29/0x1710 drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x29de/0x4f30 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Freed by task 28: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6663 [inline] kmem_cache_free+0x18f/0x8d0 mm/slub.c:6774 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core kernel/rcu/tree.c:2857 [inline] rcu_cpu_kthread+0xc96/0x1c40 kernel/rcu/tree.c:2945 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3119 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3239 kernfs_put+0x191/0x470 fs/kernfs/dir.c:591 sysfs_put include/linux/sysfs.h:808 [inline] __kobject_del+0xe9/0x330 lib/kobject.c:605 kobject_del+0x45/0x60 lib/kobject.c:627 device_del+0x763/0x8e0 drivers/base/core.c:3898 usb_disconnect+0x5fb/0x970 drivers/usb/core/hub.c:2376 hub_port_connect drivers/usb/core/hub.c:5407 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1cd9/0x4f30 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff88806684a960 which belongs to the cache kernfs_node_cache of size 176 The buggy address is located 0 bytes inside of freed 176-byte region [ffff88806684a960, ffff88806684aa10) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6684a ksm flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff88801aaf1000 ffffea00012100c0 dead000000000007 raw: 0000000000000000 0000000000110011 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5654, tgid 5654 (kworker/0:3), ts 200152700934, free_ts 199911155229 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xb10/0x1400 mm/slub.c:4651 __slab_alloc+0xc6/0x1f0 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5246 [inline] kmem_cache_alloc_noprof+0x101/0x6c0 mm/slub.c:5265 __kernfs_new_node+0xdc/0x900 fs/kernfs/dir.c:637 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:716 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:82 [inline] internal_create_group+0x667/0x1170 fs/sysfs/group.c:189 internal_create_groups fs/sysfs/group.c:229 [inline] sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:255 device_add_groups drivers/base/core.c:2836 [inline] device_add_attrs+0x1c4/0x5a0 drivers/base/core.c:2911 device_add+0x496/0xb80 drivers/base/core.c:3643 page last free pid 6946 tgid 6946 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xfe1/0x1170 mm/page_alloc.c:2943 vfree+0x2ad/0x470 mm/vmalloc.c:3466 xskq_destroy+0x40/0x60 net/xdp/xsk_queue.c:64 xsk_release+0x443/0x670 net/xdp/xsk.c:1241 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x45b/0xa80 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88806684a800: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb ffff88806684a880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806684a900: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb ^ ffff88806684a980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806684aa00: fb fb fc fc fc fc fc fc fc fc 00 00 00 00 00 00 ================================================================== --- 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