This is a note to let you know that I've just added the patch titled
ksmbd: don't allow O_TRUNC open on read-only share
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ksmbd-don-t-allow-o_trunc-open-on-read-only-share.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d592a9158a112d419f341f035d18d02f8d232def Mon Sep 17 00:00:00 2001
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Date: Sun, 7 Jan 2024 21:24:07 +0900
Subject: ksmbd: don't allow O_TRUNC open on read-only share
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
commit d592a9158a112d419f341f035d18d02f8d232def upstream.
When file is changed using notepad on read-only share(read_only = yes in
ksmbd.conf), There is a problem where existing data is truncated.
notepad in windows try to O_TRUNC open(FILE_OVERWRITE_IF) and all data
in file is truncated. This patch don't allow O_TRUNC open on read-only
share and add KSMBD_TREE_CONN_FLAG_WRITABLE check in smb2_set_info().
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/smb/server/smb2pdu.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -2971,7 +2971,7 @@ int smb2_open(struct ksmbd_work *work)
&may_flags);
if (!test_tree_conn_flag(tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) {
- if (open_flags & O_CREAT) {
+ if (open_flags & (O_CREAT | O_TRUNC)) {
ksmbd_debug(SMB,
"User does not have write permission\n");
rc = -EACCES;
@@ -5943,12 +5943,6 @@ static int smb2_set_info_file(struct ksm
}
case FILE_RENAME_INFORMATION:
{
- if (!test_tree_conn_flag(work->tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) {
- ksmbd_debug(SMB,
- "User does not have write permission\n");
- return -EACCES;
- }
-
if (buf_len < sizeof(struct smb2_file_rename_info))
return -EINVAL;
@@ -5968,12 +5962,6 @@ static int smb2_set_info_file(struct ksm
}
case FILE_DISPOSITION_INFORMATION:
{
- if (!test_tree_conn_flag(work->tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) {
- ksmbd_debug(SMB,
- "User does not have write permission\n");
- return -EACCES;
- }
-
if (buf_len < sizeof(struct smb2_file_disposition_info))
return -EINVAL;
@@ -6035,7 +6023,7 @@ int smb2_set_info(struct ksmbd_work *wor
{
struct smb2_set_info_req *req;
struct smb2_set_info_rsp *rsp;
- struct ksmbd_file *fp;
+ struct ksmbd_file *fp = NULL;
int rc = 0;
unsigned int id = KSMBD_NO_FID, pid = KSMBD_NO_FID;
@@ -6055,6 +6043,13 @@ int smb2_set_info(struct ksmbd_work *wor
rsp = smb2_get_msg(work->response_buf);
}
+ if (!test_tree_conn_flag(work->tcon, KSMBD_TREE_CONN_FLAG_WRITABLE)) {
+ ksmbd_debug(SMB, "User does not have write permission\n");
+ pr_err("User does not have write permission\n");
+ rc = -EACCES;
+ goto err_out;
+ }
+
if (!has_file_id(id)) {
id = req->VolatileFileId;
pid = req->PersistentFileId;
Patches currently in stable-queue which might be from linkinjeon@xxxxxxxxxx are
queue-6.6/ksmbd-free-ppace-array-on-error-in-parse_dacl.patch
queue-6.6/smb-client-common-fix-fortify-warnings.patch
queue-6.6/ksmbd-don-t-allow-o_trunc-open-on-read-only-share.patch
