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 6D6B12D3727 for ; Tue, 14 Jul 2026 14:39:37 +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=1784039979; cv=none; b=B3sRkDbpUxibEY0JojO8XWFjYtgqhbT+ukJuaFDHvoKa1Umey+sxJ1LDXzZTqtD04SHQ4Xf5W47fHiUF2+UQbQ9z8x+GzrxvMxdpnxG1TbSXWcnGxn6OIffEj3II28JRPMf5LdADN+RK5LS0ROiw/SxvqUqWO7vG/hF8D9/dLgA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784039979; c=relaxed/simple; bh=J0uI9xOY+3u0FGb9gi7wMD7IXIxR7sqw3Ow2kyTaZgE=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=saPl2raicalBOOeAjsvvBI0u7+RycTD+2RXGLvL7ohzB64V7pf17TgMBDDSku8lSUiQweynh4cx9Sd897snMeOtOPOextEN2fVmiIym0uKwcVygGm8UZi038NDrGAfp0d8KaD+p5uPbn2iaxNj5T4Lq4Fpy7FK8uDbIhyrmlmoA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Te40QiQ6; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Te40QiQ6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88AE41F000E9; Tue, 14 Jul 2026 14:39:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784039977; bh=vaAYt63KWu452JjBcNvHwUrFaLqz5FvB95oGOmvwgJc=; h=Subject:To:Cc:From:Date; b=Te40QiQ61IqISv4RsuuUeM3SA+d0HRIdt6MfyL04ohQKAIbmJzyRnMM03lnLYnWLF 4UcfZUmZ/ebee8zlrpDQG3g3VzkqPnIWLk2jeXj+4y98xrg4dMmNzZMvjmwC9fa2ZF YEgHhGA7hV2utrgw0M+IK/cGsVXtnARd0NQqs2f0= Subject: FAILED: patch "[PATCH] ksmbd: track the connection owning a byte-range lock" failed to apply to 5.15-stable tree To: linkinjeon@kernel.org,musaab.khan@protonmail.com,stfrench@microsoft.com Cc: From: Date: Tue, 14 Jul 2026 16:39:15 +0200 Message-ID: <2026071415-rambling-chooser-b760@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=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x c1016dd1d8b2bcd1158bbaabe94a31bb7e7431fb # git commit -s git send-email --to '' --in-reply-to '2026071415-rambling-chooser-b760@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From c1016dd1d8b2bcd1158bbaabe94a31bb7e7431fb Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Mon, 15 Jun 2026 10:00:00 +0900 Subject: [PATCH] ksmbd: track the connection owning a byte-range lock 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 diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index c1c6c1a64f60..ba24040d05eb 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -7774,9 +7774,11 @@ 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; @@ -7911,6 +7913,7 @@ int smb2_lock(struct ksmbd_work *work) goto out2; } 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); @@ -7965,11 +7968,14 @@ int smb2_lock(struct ksmbd_work *work) } 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); if (rlock) diff --git a/fs/smb/server/vfs_cache.c b/fs/smb/server/vfs_cache.c index 8c556e46cc10..39c56942ae44 100644 --- a/fs/smb/server/vfs_cache.c +++ b/fs/smb/server/vfs_cache.c @@ -484,10 +484,14 @@ 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); @@ -1303,9 +1307,15 @@ static bool session_fd_check(struct ksmbd_tree_connect *tcon, up_write(&ci->m_lock); list_for_each_entry_safe(smb_lock, tmp_lock, &fp->lock_list, flist) { - spin_lock(&conn->llist_lock); + struct ksmbd_conn *lock_conn = smb_lock->conn; + + if (!lock_conn) + continue; + spin_lock(&lock_conn->llist_lock); list_del_init(&smb_lock->clist); - spin_unlock(&conn->llist_lock); + smb_lock->conn = NULL; + spin_unlock(&lock_conn->llist_lock); + ksmbd_conn_put(lock_conn); } fp->conn = NULL; @@ -1435,6 +1445,7 @@ int ksmbd_reopen_durable_fd(struct ksmbd_work *work, struct ksmbd_file *fp) } list_for_each_entry(smb_lock, &fp->lock_list, flist) { + smb_lock->conn = ksmbd_conn_get(conn); spin_lock(&conn->llist_lock); list_add_tail(&smb_lock->clist, &conn->lock_list); spin_unlock(&conn->llist_lock); diff --git a/fs/smb/server/vfs_cache.h b/fs/smb/server/vfs_cache.h index 7d547e1a74f7..a3a9fda6de91 100644 --- a/fs/smb/server/vfs_cache.h +++ b/fs/smb/server/vfs_cache.h @@ -32,6 +32,7 @@ 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;