From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f78.google.com (mail-oa1-f78.google.com [209.85.160.78]) (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 764B2368D69 for ; Fri, 19 Jun 2026 23:56:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.78 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781913385; cv=none; b=c29RKmjkv4XgBJxI8kq/ZxuFZz4UwxJmNcSAiMAsG9w5PKsufO3ZIfVbYqBKTk/4KAK/InrIwikdcQ1rAYammlG4psz0Dj6fHaRtmn5k93V+kzyoEuDrUwL5JB+y5XaFmWVe8Ikm26x79JJSUshPdgM72OvXUGdTDaknBJOAMEM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781913385; c=relaxed/simple; bh=aAfdJLlVJcDmjdHmVH9q3g1T0k8dCsl5dmxqh6Lu7ys=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Ki7YRMIbr0bKdu9Tv/97shOq0OhmjrgIIGXHqLJBbw4mbJ5ylNwoIC+w9dXurlpmpFJ6rn0n3uv2kziLU/4dICY9J5i9nV8XZRn6bko7UlqhCirLDDkA7Pr43/CzxLEqyU3wefXVQixpsncsyOOEcBzBGzh2yKohbvtXqENCQN8= 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=209.85.160.78 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-oa1-f78.google.com with SMTP id 586e51a60fabf-441d7a137d1so3973159fac.0 for ; Fri, 19 Jun 2026 16:56:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781913381; x=1782518181; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=0ZB/J2YWf86q4RH+5UAdqXIwJKtQ8pjnjE8k/mYjT9k=; b=nfgViiiY0RcMh1/nPNbWVdAx+U86ITeZVsroPICg3tJivSMb9XqYbjQeXIN0y/UPLs yv81cX4vDsdHz6TNoAFHfVRgnYq1+YTNmE2MNEW5a6nKc5FDwh0FwOzT6R85IOcw5Rxh lToESMlfWUSuHwCkLoLjfzmeIylRnTy3SyW4frDiNV2RRtIwgK+S5ppk4RXO/szcTRNM vbzDM9xV8j/ktKh4hgV6LpPwUst5lCM2s+eYAf17yUHOVg3wnjA/Xe6PYcdRE56+jtqQ ysmzScgZiziU0way8pr76FWiC0PPNOWv3bbDhkmgy8CMwLm/0stCqExMz1Jiww/6dyWS egYA== X-Forwarded-Encrypted: i=1; AFNElJ9SpO+wk5ytAEhZuHrxsLfsC+zWgCj7JDFWbKtTkRt9uVxeb1XadY2B49pZQYiCrrLYl4Yk8PkcfwSSiraj@vger.kernel.org X-Gm-Message-State: AOJu0Yx5bbFP4rdW/W2oAVPdX1Vp3WnhU6NcOQUYIv1Y7AOoepDfZ9lz QuJlQBRTZc/wTCYcjMvKWfpYWfmnIMIJh0qM3qQGUCMfoGinGzgfwwiHJ4bh4YFn1HLTxAHO+rt LxTCsLPpePdzztHh/xuBYkcWTUyoL7Fl/Fg2YKR6NTDGTVt59th64OWYcOk4= Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1529:b0:489:7060:4b05 with SMTP id 5614622812f47-489b078592cmr4628236b6e.21.1781913381599; Fri, 19 Jun 2026 16:56:21 -0700 (PDT) Date: Fri, 19 Jun 2026 16:56:21 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a35d725.280d05a0.1060c1.0001.GAE@google.com> Subject: [syzbot] [fs?] KASAN: slab-use-after-free Read in d_alloc_parallel 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: ec039126b7fa Add linux-next specific files for 20260611 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=11f307f2580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d0d1fa2afcbce17c dashboard link: https://syzkaller.appspot.com/bug?extid=bcc49cd0a89969bb101a 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/be809c32a471/disk-ec039126.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/13ea1053e3b5/vmlinux-ec039126.xz kernel image: https://storage.googleapis.com/syzbot-assets/1bcdab47ddc8/bzImage-ec039126.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+bcc49cd0a89969bb101a@syzkaller.appspotmail.com ================================================================== 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 ffff8880273bb728 by task kworker/u8:2/1377 CPU: 1 UID: 0 PID: 1377 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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:5844 __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:1430 spin_unlock include/linux/spinlock_rt.h:109 [inline] d_alloc_parallel+0x103d/0x1630 fs/dcache.c:2826 __lookup_slow+0x82/0x2f0 fs/namei.c:1904 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] link_path_walk+0xd1e/0x18d0 fs/namei.c:2656 path_openat+0x22c/0x37e0 fs/namei.c:4855 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_open_execat+0x12b/0x590 fs/exec.c:785 alloc_bprm+0x28/0x660 fs/exec.c:1431 class_bprm_constructor fs/exec.c:1496 [inline] kernel_execve+0x87/0x930 fs/exec.c:1889 call_usermodehelper_exec_async+0x212/0x360 kernel/umh.c:109 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 1378: 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:4614 [inline] slab_alloc_node mm/slub.c:4941 [inline] kmem_cache_alloc_lru_noprof+0x354/0x6b0 mm/slub.c:4974 __d_alloc+0x37/0x6f0 fs/dcache.c:1902 d_alloc_parallel+0xe3/0x1630 fs/dcache.c:2761 __lookup_slow+0x82/0x2f0 fs/namei.c:1904 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] link_path_walk+0xd1e/0x18d0 fs/namei.c:2656 path_openat+0x22c/0x37e0 fs/namei.c:4855 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_open_execat+0x12b/0x590 fs/exec.c:785 alloc_bprm+0x28/0x660 fs/exec.c:1431 class_bprm_constructor fs/exec.c:1496 [inline] kernel_execve+0x87/0x930 fs/exec.c:1889 call_usermodehelper_exec_async+0x212/0x360 kernel/umh.c:109 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 29: 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:2699 [inline] slab_free mm/slub.c:6400 [inline] kmem_cache_free+0x187/0x6c0 mm/slub.c:6527 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core kernel/rcu/tree.c:2897 [inline] rcu_cpu_kthread+0x99e/0x1470 kernel/rcu/tree.c:2985 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:3159 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3279 dentry_kill+0x4ed/0x890 fs/dcache.c:845 finish_dput+0x1a/0x260 fs/dcache.c:1001 handle_mounts fs/namei.c:1753 [inline] step_into_slowpath+0x487/0x7e0 fs/namei.c:2104 step_into fs/namei.c:2152 [inline] walk_component fs/namei.c:2288 [inline] link_path_walk+0xd50/0x18d0 fs/namei.c:2656 path_openat+0x22c/0x37e0 fs/namei.c:4855 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_open_execat+0x12b/0x590 fs/exec.c:785 alloc_bprm+0x28/0x660 fs/exec.c:1431 class_bprm_constructor fs/exec.c:1496 [inline] kernel_execve+0x87/0x930 fs/exec.c:1889 call_usermodehelper_exec_async+0x212/0x360 kernel/umh.c:109 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff8880273bb658 which belongs to the cache dentry of size 376 The buggy address is located 208 bytes inside of freed 376-byte region [ffff8880273bb658, ffff8880273bb7d0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880273bb810 pfn:0x273ba head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000240(workingset|head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000240 ffff88801c68c500 ffff88801c68bb88 ffff88801c68bb88 raw: ffff8880273bb810 000000080012000e 00000000f5000000 0000000000000000 head: 0080000000000240 ffff88801c68c500 ffff88801c68bb88 ffff88801c68bb88 head: ffff8880273bb810 000000080012000e 00000000f5000000 0000000000000000 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 1378, tgid 1378 (kworker/u8:6), ts 9289059430, free_ts 0 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+0x265c/0x26e0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3288 [inline] allocate_slab+0x76/0x5d0 mm/slub.c:3406 new_slab mm/slub.c:3452 [inline] refill_objects+0x2d9/0x350 mm/slub.c:7333 refill_sheaf mm/slub.c:2826 [inline] __pcs_replace_empty_main+0x331/0x690 mm/slub.c:4698 alloc_from_pcs mm/slub.c:4796 [inline] slab_alloc_node mm/slub.c:4929 [inline] kmem_cache_alloc_lru_noprof+0x46b/0x6b0 mm/slub.c:4974 __d_alloc+0x37/0x6f0 fs/dcache.c:1902 d_alloc_parallel+0xe3/0x1630 fs/dcache.c:2761 __lookup_slow+0x82/0x2f0 fs/namei.c:1904 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] link_path_walk+0xd1e/0x18d0 fs/namei.c:2656 path_openat+0x22c/0x37e0 fs/namei.c:4855 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_open_execat+0x12b/0x590 fs/exec.c:785 alloc_bprm+0x28/0x660 fs/exec.c:1431 page_owner free stack trace missing Memory state around the buggy address: ffff8880273bb600: fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb ffff8880273bb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880273bb700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880273bb780: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ffff8880273bb800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== --- 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