From nobody Thu Apr 9 18:53:53 2026 Received: from mail-ot1-f71.google.com (mail-ot1-f71.google.com [209.85.210.71]) (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 1C7C62D8768 for ; Fri, 6 Mar 2026 05:22:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.71 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772774544; cv=none; b=lrBHxYP4+2UXAjkoWxyvMuRDbvdWOzxonzKXs6h/+qLVi26PACQdP7vgVRxLJOrOfWpPIIF11K8JqTLv5RBsZOFzDxp8abIaPvZJHrOGHXigXXzbnAKx8ClYlmj7GZi0BzsrcZhLLBWyz02W5k1usvS0LHPf2lr187z5dKMO+9E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772774544; c=relaxed/simple; bh=21feZ/VCJvPXENETExtfNdohDWbMQz3F9aGndQMDQgY=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=ImcwLGrVIrks3WHxo9afJK2T646G6tSWhsadEAwHjGfh2LxKjwI49XM4BLovNbfQQcQdTe8p03BaVATY055qSllfp+9FfmoDUpZUaBNWKY30eBmYbj2E6kbwNjpGk4dEL+/bvEvlIV1fVFNtKc8RcxsBcGUASwHAEj0oIe9uTjg= 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=209.85.210.71 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-f71.google.com with SMTP id 46e09a7af769-7d4c2b7f4caso61672923a34.2 for ; Thu, 05 Mar 2026 21:22:22 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772774542; x=1773379342; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=lmcK9hWyHd9ojbpsXmGm0PY9KEAvpgX5OAT7b4EsOZw=; b=HuYWZQ0eMzGqUSAv+qLaL/KMv11OPpEnDcTifL1tUkkE5TNs7SZ3E/TWjIlHSn6xQI 8z7b0piFZPiq+tsU0pWeyhTa8KGXkPeljF0pzQ79p7CdrwWxa4VXjiNYVeAHyKX5p4QC QJvYYgrmmQKkFIKJpoOh+dlzZfiZxocqlovwau5v1J2OM9+5uqR3LhmAn0H/7wmkSlfk iid6n1syR9aBXLcHxrMB1GGSsYqod9bMxV65OXP47CTKs5vMC6qohUT6Ol2n/WoPmVUW gbzurbf0lLfeRFu5i4loUpIBNA++BOJuANcd2/zSxUKu52R4uxCh2lNvXD/nOPpzXUIx CeIQ== X-Gm-Message-State: AOJu0YzUB9aZLGd1NSvuyhP+xRzSwGi6TmBLlczGKPh3io4ghJyk39oN xX/OwJyHar7s+V29is6Bfr7zqVS85iZ++o404E7SLMQLjaYxIyCmBVh/JvjG07vy6INrYD3JCG+ F7WcoFTphlNa1NFqQbcSmDrpKCUHyT0JuZ1LbjdweS/vLqqsOSJtw9LgBrnM= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:200a:b0:664:685e:76be with SMTP id 006d021491bc7-67b9bd1b19dmr743474eaf.38.1772774542060; Thu, 05 Mar 2026 21:22:22 -0800 (PST) Date: Thu, 05 Mar 2026 21:22:22 -0800 In-Reply-To: <69a9251d.a70a0220.2f119.0003.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69aa648e.050a0220.13f275.000b.GAE@google.com> Subject: Forwarded: [PATCH] namei: add debug printk to trace parent inode lock state From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com. *** Subject: [PATCH] namei: add debug printk to trace parent inode lock state Author: kartikey406@gmail.com #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git= master Add debug printk statements to trace the parent directory inode rwsem state through the symlink creation path. This helps identify which component is dropping the parent inode's i_rwsem between start_dirop() and end_dirop(), causing the unbalanced unlock WARNING in filename_symlinkat(). The printk traces: - rwsem owner/count after start_dirop() acquires the lock - rwsem owner/count after vfs_symlink() returns - rwsem owner/count at end_dirop() just before the unlock - dentry->d_parent and path->dentry at each point This is a temporary diagnostic patch and should be reverted once the root cause is identified. Reported-by: syzbot+2ed46b6b748df855347f@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3D2ed46b6b748df855347f Signed-off-by: Deepanshu Kartikey --- fs/namei.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 58f715f7657e..9584ff6dff47 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2944,6 +2944,11 @@ struct dentry *start_dirop(struct dentry *parent, st= ruct qstr *name, void end_dirop(struct dentry *de) { if (!IS_ERR(de)) { + struct inode *dir =3D d_inode(de->d_parent); + pr_warn("DEBUG: end_dirop: de=3D%px parent=3D%px inode=3D%px rwsem count= =3D%ld owner=3D%px current=3D%px\n", + de, de->d_parent, dir, + atomic_long_read(&dir->i_rwsem.count), + READ_ONCE(dir->i_rwsem.owner), current); inode_unlock(de->d_parent->d_inode); dput(de); } @@ -4922,7 +4927,9 @@ static struct dentry *filename_create(int dfd, struct= filename *name, dentry =3D start_dirop(path->dentry, &last, reval_flag | create_flags); if (IS_ERR(dentry)) goto out_drop_write; - + pr_warn("DEBUG: after start_dirop: dentry=3D%px parent=3D%px parent_inode= =3D%px rwsem owner=3D%px current=3D%px\n", + dentry, dentry->d_parent, d_inode(dentry->d_parent), + (void *)atomic_long_read(&d_inode(dentry->d_parent)->i_rwsem.count), cur= rent); if (unlikely(error)) goto fail; =20 @@ -4959,7 +4966,10 @@ EXPORT_SYMBOL(start_creating_path); */ void end_creating_path(const struct path *path, struct dentry *dentry) { - end_creating(dentry); + if (!IS_ERR(dentry)) { + inode_unlock(d_inode(path->dentry)); + dput(dentry); + } mnt_drop_write(path->mnt); path_put(path); } @@ -5639,6 +5649,10 @@ int filename_symlinkat(struct filename *from, int ne= wdfd, struct filename *to) if (!error) error =3D vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode, dentry, from->name, &delegated_inode); + pr_warn("DEBUG: after vfs_symlink: error=3D%d dentry=3D%px parent=3D%px p= arent_inode=3D%px rwsem owner=3D%px path_dentry=3D%px path_inode=3D%px\n", + error, dentry, dentry->d_parent, d_inode(dentry->d_parent), + (void *)atomic_long_read(&d_inode(path.dentry)->i_rwsem.count), + path.dentry, d_inode(path.dentry)); end_creating_path(&path, dentry); if (is_delegated(&delegated_inode)) { error =3D break_deleg_wait(&delegated_inode); --=20 2.43.0