From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f77.google.com (mail-ot1-f77.google.com [209.85.210.77]) (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 7B13A2FDC28 for ; Tue, 2 Jun 2026 16:23:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780417409; cv=none; b=uY1wIqKIVGMntIo4/ySnicKQLHSrYeX5j5167hIB8Snfi+4waMBoJTCz2PSahatwcFacjHIJaM/qcPmfz8KX3xcU2ORtah/RSSByCzazOVbdg6JRXfjKOaz2yF4VNM5fsliJw99RYjzHRr9WH8LBPEGf7yzqQzUeu9kb4H9JOHE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780417409; c=relaxed/simple; bh=KzesLpszfAALoA62pKh0QSuapaUTnTWVkXYwugsgRWY=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Lm4/uqxAfmeeqIPnH7abIhn7h1OQnIq3k7h9znhXzEG4wXchbiy9GjGlyfupQ3SgAyjDV0d5S1CKe8blvSqoKHBKucmYYZIhSaWn+CWzxUe+DsZu8dExoEAGsnQFW8kLxez0HWjGGjaSjR8HhHBcDI0bfC5/JvXTBmKsTA0iSj8= 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=209.85.210.77 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-ot1-f77.google.com with SMTP id 46e09a7af769-7e6db540d17so1158699a34.0 for ; Tue, 02 Jun 2026 09:23:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780417406; x=1781022206; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=h+cfd+ivxhMsjoBhmhDdDEOuzmPfKx6zjhO5omi8cds=; b=OJ0Mi+ArYNKWC3vp3jQ8P7JByDkh9GQWOcSrOglD9eKQgEWoAluCqQ1UvWYr2u6PRC rNqmUdMO/ZySREaIQY28H7VWtTZ0ZbIn3BoDWd74fnzVon6Cj/4ochDPz2Rs/6lDzxa+ nKSRZTYOygNqzt+SZ44Qf3Yo352xg9IFmqnsGhzDyvUiaU2gQ80MG2q05ZmQtIbqCTWM nwNXe7MbDAO1fOMjNPLozoUhMrrH4R2NoRL2tnc8L5ep36VSoFYcxnQUSFpMYYHHFgYu Yc1fIUAvnrddr9rFjUXN2IdjkfrYGT01qm+e2EkSQh+0cEXnWoWazsObozhQsYmsC+fG dsdA== X-Forwarded-Encrypted: i=1; AFNElJ9JByr0EKPyYDkL3femOLsoLGXcNtfAfxW/VmQ1VWeB2v17SrhW+BTHvZ+W/sDqmgBUKgmFF0FyWPUpKaA=@vger.kernel.org X-Gm-Message-State: AOJu0YzS1vHWngozNoKwCfg2swErvDTDWivh7w8laeKOwrYFCNYXJ80m YBJvGpPIxfRvLz07cnw8VD9vCTXk0tGFl8h6c4XYd1pJ3GAsBflWwnT9nEKmKsbMpmLkhQoOrgZ c7FPq7enI/Al9RqpGyt40NnFQ+H/MRLRzsLINURpIFBrbDugxpKPncl3vHH0= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a4a:ddd3:0:b0:69d:fc7c:ecd9 with SMTP id 006d021491bc7-69e46920acfmr194969eaf.10.1780417406503; Tue, 02 Jun 2026 09:23:26 -0700 (PDT) Date: Tue, 02 Jun 2026 09:23:26 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a1f037e.3b158e77.2846f8.0848.GAE@google.com> Subject: [syzbot] [fs?] KASAN: slab-use-after-free Read in filename_mkdirat From: syzbot To: brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: e8c2f9fdadee Merge tag 'for-7.1/hpfs-fixes' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=151aaac8580000 kernel config: https://syzkaller.appspot.com/x/.config?x=6200d9adbee6a664 dashboard link: https://syzkaller.appspot.com/bug?extid=a552beb2a6a3428fc4a8 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/962d854a5f7d/disk-e8c2f9fd.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/d265e5cb4395/vmlinux-e8c2f9fd.xz kernel image: https://storage.googleapis.com/syzbot-assets/bc268c49a6f7/bzImage-e8c2f9fd.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a552beb2a6a3428fc4a8@syzkaller.appspotmail.com FAT-fs (loop0): Invalid FSINFO signature: 0x41615252, 0x80417272 (sector = 1) ================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 Read of size 1 at addr ffff88806293ae90 by task syz.0.240/7482 CPU: 1 UID: 0 PID: 7482 Comm: syz.0.240 Not tainted syzkaller #0 PREEMPT_{RT,(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 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:574 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5842 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 rt_mutex_slowunlock+0xbf/0x8b0 kernel/locking/rtmutex.c:1426 end_dirop fs/namei.c:2952 [inline] end_creating include/linux/namei.h:123 [inline] end_creating_path fs/namei.c:4990 [inline] filename_mkdirat+0x311/0x520 fs/namei.c:5299 __do_sys_mkdirat fs/namei.c:5315 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5312 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0ad209ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0ad02f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f0ad2315fa0 RCX: 00007f0ad209ce59 RDX: 0000000000000002 RSI: 00002000000004c0 RDI: 0000000000000005 RBP: 00007f0ad2132d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0ad2316038 R14: 00007f0ad2315fa0 R15: 00007ffc131430c8 Allocated by task 7482: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_lru_noprof+0x33c/0x680 mm/slub.c:4918 __d_alloc+0x37/0x6f0 fs/dcache.c:1807 d_alloc+0x4b/0x190 fs/dcache.c:1886 lookup_one_qstr_excl+0xd8/0x360 fs/namei.c:1801 __start_dirop fs/namei.c:2916 [inline] start_dirop fs/namei.c:2938 [inline] filename_create+0x20e/0x370 fs/namei.c:4950 filename_mkdirat+0xd2/0x520 fs/namei.c:5287 __do_sys_mkdirat fs/namei.c:5315 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5312 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 28: 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:6251 [inline] kmem_cache_free+0x187/0x6c0 mm/slub.c:6378 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core kernel/rcu/tree.c:2869 [inline] rcu_cpu_kthread+0x99e/0x1470 kernel/rcu/tree.c:2957 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3131 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3251 __dentry_kill+0x4a9/0x690 fs/dcache.c:737 finish_dput+0xc9/0x480 fs/dcache.c:927 path_put+0x39/0x60 fs/namei.c:717 vfs_statx+0x138/0x200 fs/stat.c:357 vfs_fstatat fs/stat.c:373 [inline] vfs_lstat include/linux/fs.h:3212 [inline] __do_sys_newlstat fs/stat.c:524 [inline] __se_sys_newlstat fs/stat.c:518 [inline] __x64_sys_newlstat+0x125/0x1e0 fs/stat.c:518 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88806293adc0 which belongs to the cache dentry of size 376 The buggy address is located 208 bytes inside of freed 376-byte region [ffff88806293adc0, ffff88806293af38) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6293a head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88806293bef1 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88801b6e83c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800120012 00000000f5000000 ffff88806293bef1 head: 0080000000000040 ffff88801b6e83c0 dead000000000100 dead000000000122 head: 0000000000000000 0000000800120012 00000000f5000000 ffff88806293bef1 head: 0080000000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Reclaimable, gfp_mask 0xd20d0(__GFP_RECLAIMABLE|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4965, tgid 4965 (udevd), ts 96191026007, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x27c8/0x2840 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+0x33c/0x3d0 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] kmem_cache_alloc_lru_noprof+0x433/0x680 mm/slub.c:4918 __d_alloc+0x37/0x6f0 fs/dcache.c:1807 d_alloc_parallel+0xe6/0x1610 fs/dcache.c:2671 __lookup_slow+0x152/0x440 fs/namei.c:1900 lookup_slow+0x53/0x70 fs/namei.c:1932 walk_component fs/namei.c:2278 [inline] lookup_last fs/namei.c:2785 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2809 filename_lookup+0x256/0x5d0 fs/namei.c:2838 vfs_statx+0xfc/0x200 fs/stat.c:353 vfs_fstatat+0x11b/0x170 fs/stat.c:373 __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 page_owner free stack trace missing Memory state around the buggy address: ffff88806293ad80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88806293ae00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806293ae80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806293af00: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa ffff88806293af80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. 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