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| author | Namjae Jeon <linkinjeon@kernel.org> | 2024-01-07 21:24:07 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-20 11:50:10 +0100 |
| commit | 09d84f37f8412fbb2bd73447bbecb68310e4b378 (patch) | |
| tree | e790772b4f89115084112a8328aecd1218aaa16a | |
| parent | c24fc060ab7fd2536830234428ffea649d318ffb (diff) | |
| download | linux-stable-09d84f37f8412fbb2bd73447bbecb68310e4b378.tar.gz linux-stable-09d84f37f8412fbb2bd73447bbecb68310e4b378.tar.bz2 linux-stable-09d84f37f8412fbb2bd73447bbecb68310e4b378.zip | |
ksmbd: don't allow O_TRUNC open on read-only share
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@vger.kernel.org
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/smb/server/smb2pdu.c | 23 |
1 files changed, 9 insertions, 14 deletions
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 6e5ed0ac578a..46070951d163 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2969,7 +2969,7 @@ 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; @@ -5941,12 +5941,6 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp, } 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; @@ -5966,12 +5960,6 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp, } 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; @@ -6033,7 +6021,7 @@ int smb2_set_info(struct ksmbd_work *work) { 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; @@ -6053,6 +6041,13 @@ int smb2_set_info(struct ksmbd_work *work) 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; |