Commit 7b9c44ca authored by Hobin Woo's avatar Hobin Woo Committed by Long Li
Browse files

ksmbd: discard write access to the directory open 

stable inclusion
from stable-v6.6.40
commit 9e84b1ba5c98fb5c9f869c85db1d870354613baa
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGELQ
CVE: CVE-2024-41030

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=tags/v6.6.41&id=9e84b1ba5c98fb5c9f869c85db1d870354613baa



--------------------------------

may_open() does not allow a directory to be opened with the write access.
However, some writing flags set by client result in adding write access
on server, making ksmbd incompatible with FUSE file system. Simply, let's
discard the write access when opening a directory.

list_add corruption. next is NULL.
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:26!
pc : __list_add_valid+0x88/0xbc
lr : __list_add_valid+0x88/0xbc
Call trace:
__list_add_valid+0x88/0xbc
fuse_finish_open+0x11c/0x170
fuse_open_common+0x284/0x5e8
fuse_dir_open+0x14/0x24
do_dentry_open+0x2a4/0x4e0
dentry_open+0x50/0x80
smb2_open+0xbe4/0x15a4
handle_ksmbd_work+0x478/0x5ec
process_one_work+0x1b4/0x448
worker_thread+0x25c/0x430
kthread+0x104/0x1d4
ret_from_fork+0x10/0x20

Cc: stable@vger.kernel.org
Signed-off-by: default avatarYoonho Shin <yoonho.shin@samsung.com>
Signed-off-by: default avatarHobin Woo <hobin.woo@samsung.com>
Acked-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
Conflicts:
	fs/smb/server/smb2pdu.c
	fs/ksmbd/smb2pdu.c
[lc:file path is not same]
Signed-off-by: default avatarLong Li <leo.lilong@huawei.com>
parent e1994ce0

fs/ksmbd/smb2pdu.c

+11 −2
Original line number Diff line number Diff line
@@ -2047,15 +2047,22 @@ int smb2_tree_connect(struct ksmbd_work *work) 
 * @access:		file access flags

 * @disposition:	file disposition flags

 * @may_flags:		set with MAY_ flags

 * @is_dir:		is creating open flags for directory

 *

 * Return:      file open flags

 */

static int smb2_create_open_flags(bool file_present, __le32 access,

				  __le32 disposition,

				  int *may_flags)

				  int *may_flags,

				  bool is_dir)

{

	int oflags = O_NONBLOCK | O_LARGEFILE;



	if (is_dir) {

		access &= ~FILE_WRITE_DESIRE_ACCESS_LE;

		ksmbd_debug(SMB, "Discard write access to a directory\n");

	}



	if (access & FILE_READ_DESIRED_ACCESS_LE &&

	    access & FILE_WRITE_DESIRE_ACCESS_LE) {

		oflags |= O_RDWR;
@@ -2895,7 +2902,9 @@ int smb2_open(struct ksmbd_work *work) 


	open_flags = smb2_create_open_flags(file_present, daccess,

					    req->CreateDisposition,

					    &may_flags);

					    &may_flags,

		req->CreateOptions & FILE_DIRECTORY_FILE_LE ||

		(file_present && S_ISDIR(d_inode(path.dentry)->i_mode)));



	if (!test_tree_conn_flag(tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) {

		if (open_flags & O_CREAT) {