From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D5A952698AE; Tue, 8 Apr 2025 12:02:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744113731; cv=none; b=u1AHNkyVmjrtoSz07Jmh6XYWGnos+v6+9nELwcmr/JtmwsX7GTceb9Xq7+VY0zaJ9MY0bJUg/ns24ccsERieA6k2N8/09LYUNslTDISQCbDruDKKGn88x7CFo17S0bnBprrybIYHMcjWCjbxzV6nkVyVSSzZpkcT9iHfQZCF+JE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744113731; c=relaxed/simple; bh=1GW5evtOVi+VdbfzLCB/Q5jBkoxfrODoJAL0LyRsP1o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EnILuxLlyXsyCzUPgp43oKDHdxZYiLOI7UMohiecRCwfuTYrEzSkZpY7H+UWiBNglZcBS0UkcXgoM40QPsYv8qAn4+6qv4guvKUdNfBPGkat00seYVFfcFoC+1kLJaWBSchQRWUcX8ZPdXzv0wuifNY0nPdGJsXBfnOrkCm8Qos= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JbBITOSF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JbBITOSF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64ADBC4CEE5; Tue, 8 Apr 2025 12:02:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744113731; bh=1GW5evtOVi+VdbfzLCB/Q5jBkoxfrODoJAL0LyRsP1o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JbBITOSFk0E+9lid1Aaf0iQ27GsfThDmPHaY5ZISiEe9/QRvqyu13HQ6cVl0fllxP GwAfdQyBdyIqmF+X7C1iKHjZmyUzNYPDBZQWCkHaNlSjGt6OghKXr+nxtc7JAxDfEZ 3EV7XmwjoC/6apj25FZD22I/4wa0bugPQFkOrg+g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Li Lingfeng , Jeff Layton , Chuck Lever Subject: [PATCH 6.6 267/268] nfsd: put dl_stid if fail to queue dl_recall Date: Tue, 8 Apr 2025 12:51:18 +0200 Message-ID: <20250408104835.776902127@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250408104828.499967190@linuxfoundation.org> References: <20250408104828.499967190@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Lingfeng commit 230ca758453c63bd38e4d9f4a21db698f7abada8 upstream. Before calling nfsd4_run_cb to queue dl_recall to the callback_wq, we increment the reference count of dl_stid. We expect that after the corresponding work_struct is processed, the reference count of dl_stid will be decremented through the callback function nfsd4_cb_recall_release. However, if the call to nfsd4_run_cb fails, the incremented reference count of dl_stid will not be decremented correspondingly, leading to the following nfs4_stid leak: unreferenced object 0xffff88812067b578 (size 344): comm "nfsd", pid 2761, jiffies 4295044002 (age 5541.241s) hex dump (first 32 bytes): 01 00 00 00 6b 6b 6b 6b b8 02 c0 e2 81 88 ff ff ....kkkk........ 00 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 ad 4e ad de .kkkkkkk.....N.. backtrace: kmem_cache_alloc+0x4b9/0x700 nfsd4_process_open1+0x34/0x300 nfsd4_open+0x2d1/0x9d0 nfsd4_proc_compound+0x7a2/0xe30 nfsd_dispatch+0x241/0x3e0 svc_process_common+0x5d3/0xcc0 svc_process+0x2a3/0x320 nfsd+0x180/0x2e0 kthread+0x199/0x1d0 ret_from_fork+0x30/0x50 ret_from_fork_asm+0x1b/0x30 unreferenced object 0xffff8881499f4d28 (size 368): comm "nfsd", pid 2761, jiffies 4295044005 (age 5541.239s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 30 4d 9f 49 81 88 ff ff ........0M.I.... 30 4d 9f 49 81 88 ff ff 20 00 00 00 01 00 00 00 0M.I.... ....... backtrace: kmem_cache_alloc+0x4b9/0x700 nfs4_alloc_stid+0x29/0x210 alloc_init_deleg+0x92/0x2e0 nfs4_set_delegation+0x284/0xc00 nfs4_open_delegation+0x216/0x3f0 nfsd4_process_open2+0x2b3/0xee0 nfsd4_open+0x770/0x9d0 nfsd4_proc_compound+0x7a2/0xe30 nfsd_dispatch+0x241/0x3e0 svc_process_common+0x5d3/0xcc0 svc_process+0x2a3/0x320 nfsd+0x180/0x2e0 kthread+0x199/0x1d0 ret_from_fork+0x30/0x50 ret_from_fork_asm+0x1b/0x30 Fix it by checking the result of nfsd4_run_cb and call nfs4_put_stid if fail to queue dl_recall. Cc: stable@vger.kernel.org Signed-off-by: Li Lingfeng Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfs4state.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1066,6 +1066,12 @@ static struct nfs4_ol_stateid * nfs4_all return openlockstateid(stid); } +/* + * As the sc_free callback of deleg, this may be called by nfs4_put_stid + * in nfsd_break_one_deleg. + * Considering nfsd_break_one_deleg is called with the flc->flc_lock held, + * this function mustn't ever sleep. + */ static void nfs4_free_deleg(struct nfs4_stid *stid) { struct nfs4_delegation *dp = delegstateid(stid); @@ -4920,6 +4926,7 @@ static const struct nfsd4_callback_ops n static void nfsd_break_one_deleg(struct nfs4_delegation *dp) { + bool queued; /* * We're assuming the state code never drops its reference * without first removing the lease. Since we're in this lease @@ -4928,7 +4935,10 @@ static void nfsd_break_one_deleg(struct * we know it's safe to take a reference. */ refcount_inc(&dp->dl_stid.sc_count); - WARN_ON_ONCE(!nfsd4_run_cb(&dp->dl_recall)); + queued = nfsd4_run_cb(&dp->dl_recall); + WARN_ON_ONCE(!queued); + if (!queued) + nfs4_put_stid(&dp->dl_stid); } /* Called from break_lease() with flc_lock held. */