From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo2-f11.google.com (mail-oo2-f11.google.com [74.125.231.139]) (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 6B5292ED16D for ; Mon, 7 Sep 2026 01:55:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.139 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788746136; cv=none; b=Ljb8SSRLUZl5l40vfxDtpb/4ZYlvcFJjbUdodvx3s8pUtIAy/EKKGDJ1kAz1J+k/nHPSN5bjlLIQ705m/KDI4U9Y8zRaRJkZH8J4YlL96PTsi8qzmPmnsdeC8Lr/PeiZxWGPAew2H+D2D7k3UgwoX7LzCmYqwaChS9GTt+Bv84o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788746136; c=relaxed/simple; bh=5ghn7nxvgfAiAWaBixedr2h12wQs1M4XKcGJABNW0/o=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=AKdxzEC460MciLYcBKV32fCqcLSCmeQeohAZtEUTfGKv3cnZzxluqC8G+Ej+82fqsYl09bjyctWhFLjdD5hPDM4zEsqs0bcptWXhuwKW2b200xO5AnKexahr3Mt7rz6f6pJMNCGGbMP+jLuGO2k526fYKoDLFfilgJSWGyVMUn8= 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=74.125.231.139 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-oo2-f11.google.com with SMTP id 006d021491bc7-6b1b7b6ac7fso901597eaf.0 for ; Sun, 06 Sep 2026 18:55:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788746133; x=1789350933; 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=kbZ2OnDIqN2FzfMGx2pAG1gARfawZnOqcaUIj2YUYrA=; b=ApUoABTsU/KxALdU8NpXVLHqNI5aSvgrBwcn9BuE7QUDLmm1RgzwTzocKRa+erogJe HePVWWOr0AvBU48w+9lHaMskdm1sz6jynZSkLj/9Qwcw6b5t4nBlg0g1eMDtpnBjffPa +FnDwBEqYRha9QWuef2Oe5ml893bqR9uyj9xa2E90r567IM/1HPo+B9Tnw4KZUplmOW8 iNzcppU1cr2epDgPI12FbjjpgRA052XzphnuZ3zVxqhlhGyaDLvvB4Vm9CoTg+dV1DZh nAvIgqC1QNAe9/Ckf9yDElqLUeVap0IpAk6PnJ3SYoaY1aoKoTmP38ePU4OWoQVMak2E Ba1g== X-Forwarded-Encrypted: i=1; AKwUvByVNpQotmS99zqqLjtu8O6/VolbKnYxpyfQIbcf4P99nGjTacY7am0FRa84TrkDNVBHAv46LT51MNrnJ+0=@vger.kernel.org X-Gm-Message-State: AFuF++laQz4f3CQojQL54DSwJlaDmb3dYAxT2X75ZDKDqU963ysM2JSY nAqHFxL8IVReGlxwVHHuM2bAXsoPjEZK6rqcureQtxeQ4Ypf67eWLyagH0mwqd1Q9RW0PwxjZVF uOt7KhoyXfyxCGXgS/fkLqCRBOIiPaGcZHGdhCRXEpeh0+lOMTaC46GpoEeU= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1501:b0:6b7:83c5:fdea with SMTP id 006d021491bc7-6b783c60367mr11036533eaf.43.1788746133211; Sun, 06 Sep 2026 18:55:33 -0700 (PDT) Date: Sun, 06 Sep 2026 18:55:33 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a9e1995.a5e650b3.26d8a.0024.GAE@google.com> Subject: [syzbot] [jffs2?] possible deadlock in jffs2_xattr_delete_inode From: syzbot To: dwmw2@infradead.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, richard@nod.at, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 940de590b839 Merge tag 'hardening-v7.3-rc2' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11d190f9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=85bc5cc2fc7394d9 dashboard link: https://syzkaller.appspot.com/bug?extid=fdfd8fdf716c90baef0f compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-940de590.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/f3f674f98efb/vmlinux-940de590.xz kernel image: https://storage.googleapis.com/syzbot-assets/132222426e71/bzImage-940de590.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fdfd8fdf716c90baef0f@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kswapd0/111 is trying to acquire lock: ffff8880266529d8 (&c->xattr_sem){++++}-{4:4}, at: jffs2_xattr_delete_inode+0x83/0x130 fs/jffs2/xattr.c:605 but task is already holding lock: ffffffff8efc8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xbce/0x1f00 mm/vmscan.c:7292 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: lock_acquire kernel/locking/lockdep.c:5908 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865 __fs_reclaim_acquire mm/page_alloc.c:4375 [inline] fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4389 might_alloc include/linux/sched/mm.h:316 [inline] slab_pre_alloc_hook mm/slub.c:4636 [inline] slab_alloc_node mm/slub.c:4974 [inline] kmem_cache_alloc_noprof+0x63/0x6a0 mm/slub.c:5010 jffs2_alloc_xattr_datum+0x1c/0xe0 fs/jffs2/malloc.c:264 create_xattr_datum fs/jffs2/xattr.c:363 [inline] do_jffs2_setxattr+0x6f0/0x1610 fs/jffs2/xattr.c:1175 __vfs_setxattr+0x175/0x1e0 fs/xattr.c:223 __vfs_setxattr_noperm+0x127/0x660 fs/xattr.c:257 __vfs_setxattr_locked+0x127/0x2b0 fs/xattr.c:318 vfs_setxattr+0x14a/0x390 fs/xattr.c:344 ovl_do_setxattr fs/overlayfs/overlayfs.h:324 [inline] ovl_setxattr fs/overlayfs/overlayfs.h:336 [inline] ovl_make_workdir fs/overlayfs/super.c:724 [inline] ovl_get_workdir fs/overlayfs/super.c:836 [inline] ovl_fill_super_creds fs/overlayfs/super.c:1449 [inline] ovl_fill_super+0x1320/0x5ea0 fs/overlayfs/super.c:1561 vfs_get_super fs/super.c:1405 [inline] get_tree_nodev+0xdd/0x190 fs/super.c:1424 vfs_get_tree+0x92/0x320 fs/super.c:1947 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3772 [inline] do_new_mount fs/namespace.c:3848 [inline] path_mount+0x7d0/0x24c0 fs/namespace.c:4168 do_mount fs/namespace.c:4181 [inline] __do_sys_mount fs/namespace.c:4397 [inline] __se_sys_mount fs/namespace.c:4374 [inline] __ia32_sys_mount+0x292/0x310 fs/namespace.c:4374 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #0 (&c->xattr_sem){++++}-{4:4}: check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181 check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5254 lock_acquire kernel/locking/lockdep.c:5908 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865 down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1631 jffs2_xattr_delete_inode+0x83/0x130 fs/jffs2/xattr.c:605 jffs2_do_clear_inode+0x50/0x470 fs/jffs2/readinode.c:1418 evict+0x3c2/0xad0 fs/inode.c:822 iput_final fs/inode.c:2015 [inline] iput.part.0+0x989/0x1050 fs/inode.c:2064 iput+0x35/0x40 fs/inode.c:2030 dentry_unlink_inode+0x284/0x470 fs/dcache.c:479 dentry_kill+0x25d/0xc20 fs/dcache.c:826 finish_dput fs/dcache.c:1001 [inline] dput.part.0+0xd7/0x240 fs/dcache.c:1042 dput+0x1f/0x30 fs/dcache.c:1037 ovl_destroy_inode+0x3e/0x190 fs/overlayfs/super.c:217 destroy_inode+0xcb/0x1c0 fs/inode.c:387 evict+0x599/0xad0 fs/inode.c:846 iput_final fs/inode.c:2015 [inline] iput.part.0+0x989/0x1050 fs/inode.c:2064 iput+0x35/0x40 fs/inode.c:2030 dentry_unlink_inode+0x284/0x470 fs/dcache.c:479 dentry_kill+0x25d/0xc20 fs/dcache.c:826 shrink_kill fs/dcache.c:1275 [inline] shrink_dentry_list+0x1e8/0x310 fs/dcache.c:1292 prune_dcache_sb+0xea/0x150 fs/dcache.c:1374 super_cache_scan+0x361/0x5c0 fs/super.c:238 do_shrink_slab+0x416/0x1200 mm/shrinker.c:443 shrink_slab_memcg mm/shrinker.c:560 [inline] shrink_slab+0xa82/0x12e0 mm/shrinker.c:638 shrink_one+0x398/0x850 mm/vmscan.c:5119 shrink_many mm/vmscan.c:5180 [inline] lru_gen_shrink_node mm/vmscan.c:5258 [inline] shrink_node+0x2b20/0x4320 mm/vmscan.c:6247 kswapd_shrink_node mm/vmscan.c:7101 [inline] balance_pgdat+0xb20/0x1f00 mm/vmscan.c:7279 kswapd+0x556/0xb50 mm/vmscan.c:7555 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&c->xattr_sem); lock(fs_reclaim); lock(&c->xattr_sem); *** DEADLOCK *** locks held by kswapd0/111: 2, last CPU#2: #0: ffffffff8efc8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xbce/0x1f00 mm/vmscan.c:7292 #1: ffff888025eec0e8 (&type->s_umount_key#56){++++}-{4:4}, at: super_trylock_shared fs/super.c:688 [inline] #1: ffff888025eec0e8 (&type->s_umount_key#56){++++}-{4:4}, at: super_cache_scan+0x9b/0x5c0 fs/super.c:213 stack backtrace: CPU: 2 UID: 0 PID: 111 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2059 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2191 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3181 check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x1492/0x1ec0 kernel/locking/lockdep.c:5254 lock_acquire kernel/locking/lockdep.c:5908 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5865 down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1631 jffs2_xattr_delete_inode+0x83/0x130 fs/jffs2/xattr.c:605 jffs2_do_clear_inode+0x50/0x470 fs/jffs2/readinode.c:1418 evict+0x3c2/0xad0 fs/inode.c:822 iput_final fs/inode.c:2015 [inline] iput.part.0+0x989/0x1050 fs/inode.c:2064 iput+0x35/0x40 fs/inode.c:2030 dentry_unlink_inode+0x284/0x470 fs/dcache.c:479 dentry_kill+0x25d/0xc20 fs/dcache.c:826 finish_dput fs/dcache.c:1001 [inline] dput.part.0+0xd7/0x240 fs/dcache.c:1042 dput+0x1f/0x30 fs/dcache.c:1037 ovl_destroy_inode+0x3e/0x190 fs/overlayfs/super.c:217 destroy_inode+0xcb/0x1c0 fs/inode.c:387 evict+0x599/0xad0 fs/inode.c:846 iput_final fs/inode.c:2015 [inline] iput.part.0+0x989/0x1050 fs/inode.c:2064 iput+0x35/0x40 fs/inode.c:2030 dentry_unlink_inode+0x284/0x470 fs/dcache.c:479 dentry_kill+0x25d/0xc20 fs/dcache.c:826 shrink_kill fs/dcache.c:1275 [inline] shrink_dentry_list+0x1e8/0x310 fs/dcache.c:1292 prune_dcache_sb+0xea/0x150 fs/dcache.c:1374 super_cache_scan+0x361/0x5c0 fs/super.c:238 do_shrink_slab+0x416/0x1200 mm/shrinker.c:443 shrink_slab_memcg mm/shrinker.c:560 [inline] shrink_slab+0xa82/0x12e0 mm/shrinker.c:638 shrink_one+0x398/0x850 mm/vmscan.c:5119 shrink_many mm/vmscan.c:5180 [inline] lru_gen_shrink_node mm/vmscan.c:5258 [inline] shrink_node+0x2b20/0x4320 mm/vmscan.c:6247 kswapd_shrink_node mm/vmscan.c:7101 [inline] balance_pgdat+0xb20/0x1f00 mm/vmscan.c:7279 kswapd+0x556/0xb50 mm/vmscan.c:7555 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 --- 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