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 23AAC433036 for ; Thu, 16 Jul 2026 18:22:15 +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=1784226143; cv=none; b=Z91RlbBMdYPg5n6+k5dZf4souBWEkOLh0BjWorT1qXYsy+Hc+Ez3lMmTzBIRFaKM/HyIpLsMGUYONOBb7ASG6dYFsLdvyhP2QSWQDdFbOJvcKhhxeFwlBw0cfWibnWXWHrv/eHhbh/0c7XlpkV5chfESmAB7U7E1Ja+j/ppKjBQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784226143; c=relaxed/simple; bh=5IY/DaWI5VgIvr/ei08fE0149pbbp+TykOoNoOa9TCg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N/9DTEL0wsSHrCbeMHuAJrm2fLDQhmhBIrwZak2hMjRuza47/inY4dJKTTR5Rgf4gMLRUwna+CxceC2zHBTC6fl4I5rt2LPyYQxVZ9kUVBRR9VcbcnYehKi1674Cf4hS3hwjSqqdewUTzl+V/Xs2cUnA/6ZG8qatW5D6a4ZA+9o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EtB7sChF; 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="EtB7sChF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3A241F00A3A; Thu, 16 Jul 2026 18:22:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784226133; bh=8VbbAuHGlMo4iBP9lwqsoupyjvBrSjhycJjRryEnSi8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=EtB7sChFmjVZYud29BZ31j+dlUXC8uo+p9uZl/bjITKjMsezzwy2G8lWvIMJOOgiN Qkwo1V2OdYtoJ1pAhhGYe+nBkD4ZHea7mktMb4k75LGLOTksXv6wpKnMnqJqE91ZDs Xmms0ncDaSBuJbKy87dlkeyScl+jIukKpD/HJS34tEbxZlOHrhsdtQE4Z4pngY6/UR 9mxPR0wWiwpP8GyqG8s2QnXL4Q5MG2eITLsUp4dDJ/7Q6oaxyireIjHT7jN/EE8t9a 8amSZ1GI7poERstCz5CxOWSrxJnuBbLq807vzbjRcT9OAeCV6c32pKoVdsl/BcVVm3 CBjgSkJC165AA== From: Sasha Levin To: stable@vger.kernel.org Cc: Namjae Jeon , Musaab Khan , Steve French , Sasha Levin Subject: [PATCH 5.15.y 7/7] ksmbd: track the connection owning a byte-range lock Date: Thu, 16 Jul 2026 14:22:05 -0400 Message-ID: <20260716182205.921233-7-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260716182205.921233-1-sashal@kernel.org> References: <2026071415-rambling-chooser-b760@gregkh> <20260716182205.921233-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Namjae Jeon [ Upstream commit c1016dd1d8b2bcd1158bbaabe94a31bb7e7431fb ] SMB2_LOCK adds each granted byte-range lock to both the file lock list and the lock list of the connection which handled the request. The final close and durable handle paths, however, remove the connection list entry while holding fp->conn->llist_lock. With SMB3 multichannel, the connection handling the LOCK request can be different from the connection which opened the file. The entry can therefore be removed under a different spinlock from the one protecting the list it belongs to. A concurrent traversal can then access freed struct ksmbd_lock and struct file_lock objects. Record the connection owning each lock's clist entry and hold a reference to it while the entry is linked. Use that connection and its llist_lock for unlock, rollback, close, and durable preserve. Durable reconnect assigns the new connection as the owner when publishing the locks again. Fixes: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel") Cc: stable@vger.kernel.org Reported-by: Musaab Khan Signed-off-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/ksmbd/smb2pdu.c | 10 ++++++++-- fs/ksmbd/vfs_cache.c | 12 ++++++++---- fs/ksmbd/vfs_cache.h | 1 + 3 files changed, 17 insertions(+), 6 deletions(-) diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index af1e386cedb43b..aaab177c7ac1e5 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -7074,9 +7074,11 @@ int smb2_lock(struct ksmbd_work *work) nolock = 0; list_del(&cmp_lock->flist); list_del(&cmp_lock->clist); + cmp_lock->conn = NULL; spin_unlock(&conn->llist_lock); up_read(&conn_list_lock); + ksmbd_conn_put(conn); locks_free_lock(cmp_lock->fl); kfree(cmp_lock); goto out_check_cl; @@ -7212,6 +7214,7 @@ int smb2_lock(struct ksmbd_work *work) goto retry; } else if (!rc) { list_add(&smb_lock->llist, &rollback_list); + smb_lock->conn = ksmbd_conn_get(work->conn); spin_lock(&work->conn->llist_lock); list_add_tail(&smb_lock->clist, &work->conn->lock_list); @@ -7259,11 +7262,14 @@ int smb2_lock(struct ksmbd_work *work) pr_err("rollback unlock fail : %d\n", rc); list_del(&smb_lock->llist); - spin_lock(&work->conn->llist_lock); + conn = smb_lock->conn; + spin_lock(&conn->llist_lock); if (!list_empty(&smb_lock->flist)) list_del(&smb_lock->flist); list_del(&smb_lock->clist); - spin_unlock(&work->conn->llist_lock); + smb_lock->conn = NULL; + spin_unlock(&conn->llist_lock); + ksmbd_conn_put(conn); locks_free_lock(smb_lock->fl); locks_free_lock(rlock); diff --git a/fs/ksmbd/vfs_cache.c b/fs/ksmbd/vfs_cache.c index 4e7a259964a15f..201ed5055aa084 100644 --- a/fs/ksmbd/vfs_cache.c +++ b/fs/ksmbd/vfs_cache.c @@ -317,10 +317,14 @@ static void __ksmbd_close_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp) * there are not accesses to fp->lock_list. */ list_for_each_entry_safe(smb_lock, tmp_lock, &fp->lock_list, flist) { - if (!list_empty(&smb_lock->clist) && fp->conn) { - spin_lock(&fp->conn->llist_lock); - list_del(&smb_lock->clist); - spin_unlock(&fp->conn->llist_lock); + struct ksmbd_conn *conn = smb_lock->conn; + + if (conn) { + spin_lock(&conn->llist_lock); + list_del_init(&smb_lock->clist); + smb_lock->conn = NULL; + spin_unlock(&conn->llist_lock); + ksmbd_conn_put(conn); } list_del(&smb_lock->flist); diff --git a/fs/ksmbd/vfs_cache.h b/fs/ksmbd/vfs_cache.h index a528f0cc775ae0..cd61c0b85e4d63 100644 --- a/fs/ksmbd/vfs_cache.h +++ b/fs/ksmbd/vfs_cache.h @@ -30,6 +30,7 @@ struct ksmbd_session; struct ksmbd_lock { struct file_lock *fl; + struct ksmbd_conn *conn; struct list_head clist; struct list_head flist; struct list_head llist; -- 2.53.0