From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1843D383333 for ; Mon, 31 Aug 2026 21:09:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788210590; cv=none; b=UmXMWqM4DrmgR+soWEvQj9HNnTX4ocNI1p4uLWKa1Czw1GCBviTuothtQmYrbUE3Kww6uIg0cIa++MDGNcWctbO+pe1U5rHbZ6guSs0uETPTmvniejBVfoTaIDJOCnar0eDNYWDP6VdGBsjTimBc5lewcM1N6rIqTwvpGPCXUHA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788210590; c=relaxed/simple; bh=vkCqt8mSgoDljan4xP5OLRXdPZMWnCccCLHMmlYxflc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mOxccCqIgOeQGXy8gPnCv6V9xer8wf7DrCegB12BQBvgmdzlxx4PqGVlDwWFi2OMPeD8lezHICvJAnZK4oGQA5QVtmNLBhEQ+TnY4BNXoXWq0FTepwg6/StiWXHIqRcsn9xmn4QZD4mXV9GZYpII4gLsvqvAFQvta1PxcfqF3Wk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hvUCIdJp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hvUCIdJp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75F361F000E9; Mon, 31 Aug 2026 21:09:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788210589; bh=04gSYx42Z9t1RC0wNSJeZi99m4FYQ+qlOEnUVci+N64=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=hvUCIdJpamzyElIg6YLalln2yOV+4SNbNuq6ReWjBUNgrMrit5K/iWZQXWWwGV43k Xqiq6SFRgopgFTjIBGN2eBUa5oalAFQtyBRLX7MCgso8neu4JgFvZObzpFerhYjS9f oTJ5bSOjXIoeyPTU6jB1COnqn+iB/r5JQUIQC2kp4/ieVzMlHbp2OE0kkdbBVc/f4L +bI5r3Crjg7P/Lc85PchBCyHbYRcfZPyS2u5gkoD1SBqXUmQ70+/EfwZTIWID26KJ+ DXpSl7SwoiEn03m/n1BWbP5GD3yhMB9LtesKKYPPLd+AoulL853jUcv9Ru0YIYL+Yo w0h8iodQu5pZQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Baokun Li , Miklos Szeredi , Sasha Levin Subject: [PATCH 5.10.y] fuse: fix invalidate lock leak on setattr writeback failure Date: Mon, 31 Aug 2026 17:09:46 -0400 Message-ID: <20260831210946.1798411-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026083119-surname-nimble-f2a7@gregkh> References: <2026083119-surname-nimble-f2a7@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Baokun Li [ Upstream commit 9afeca0d569c9fc89d758fe7a9339d1e8afb1546 ] fuse_do_setattr() takes filemap_invalidate_lock() for a DAX truncate (fault_blocked = true) and releases it at the out:/error: labels. But when a writeback flush is also needed, a write_inode_now() failure returns directly and leaks the lock, so any later fault or truncate on the file stalls on the stale rwsem. For example, truncate(2) on a setuid file reaches fuse_do_setattr() with both ATTR_SIZE and ATTR_MODE set: truncate(2) └─ do_truncate() ├─ dentry_needs_remove_privs() # S_ISUID └─ notify_change() # KILL_SUID -> ATTR_MODE └─ fuse_setattr() # no killpriv: │ # ia_valid |= ATTR_MODE └─ fuse_do_setattr() ├─ filemap_invalidate_lock() # IS_DAX && is_truncate └─ write_inode_now() # is_wb && ATTR_MODE └─ if (err) # e.g. daemon -> -EIO return err # <- lock leaked Fix this by adding an unlock label that releases the lock before returning the error, and use it for the fuse_dax_break_layouts() failure path as well. Fixes: 6ae330cad6ef ("virtiofs: serialize truncate/punch_hole and dax fault path") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Baokun Li Signed-off-by: Miklos Szeredi [ replaced up_write(&fi->i_mmap_sem) locking and (inode, 0, 0) call site instead of the mainline filemap_invalidate_lock/(inode, 0, -1) forms ] Signed-off-by: Sasha Levin --- fs/fuse/dir.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 4488a53a192dc..d475d19193848 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1651,10 +1651,8 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, down_write(&fi->i_mmap_sem); fault_blocked = true; err = fuse_dax_break_layouts(inode, 0, 0); - if (err) { - up_write(&fi->i_mmap_sem); - return err; - } + if (err) + goto unlock; } if (attr->ia_valid & ATTR_OPEN) { @@ -1681,7 +1679,7 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, ATTR_TIMES_SET)) { err = write_inode_now(inode, true); if (err) - return err; + goto unlock; fuse_set_nowrite(inode); fuse_release_nowrite(inode); @@ -1768,6 +1766,7 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); +unlock: if (fault_blocked) up_write(&fi->i_mmap_sem); return err; -- 2.53.0