From: Pali Rohár Date: Mon, 9 Dec 2024 19:44:23 +0000 (+0100) Subject: cifs: Add fallback for SMB2 CREATE without FILE_READ_ATTRIBUTES X-Git-Tag: v6.15-rc1~16^2~5 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=e255612b5ed9f179abe8196df7c2ba09dd227900;p=linux-block.git cifs: Add fallback for SMB2 CREATE without FILE_READ_ATTRIBUTES Some operations, like WRITE, does not require FILE_READ_ATTRIBUTES access. So when FILE_READ_ATTRIBUTES is not explicitly requested for smb2_open_file() then first try to do SMB2 CREATE with FILE_READ_ATTRIBUTES access (like it was before) and then fallback to SMB2 CREATE without FILE_READ_ATTRIBUTES access (less common case). This change allows to complete WRITE operation to a file when it does not grant FILE_READ_ATTRIBUTES permission and its parent directory does not grant READ_DATA permission (parent directory READ_DATA is implicit grant of child FILE_READ_ATTRIBUTES permission). Signed-off-by: Pali Rohár Signed-off-by: Steve French --- diff --git a/fs/smb/client/smb2file.c b/fs/smb/client/smb2file.c index d609a20fb98a..2d726e9b950c 100644 --- a/fs/smb/client/smb2file.c +++ b/fs/smb/client/smb2file.c @@ -152,16 +152,25 @@ int smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, __u32 int err_buftype = CIFS_NO_BUFFER; struct cifs_fid *fid = oparms->fid; struct network_resiliency_req nr_ioctl_req; + bool retry_without_read_attributes = false; smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb); if (smb2_path == NULL) return -ENOMEM; - oparms->desired_access |= FILE_READ_ATTRIBUTES; + if (!(oparms->desired_access & FILE_READ_ATTRIBUTES)) { + oparms->desired_access |= FILE_READ_ATTRIBUTES; + retry_without_read_attributes = true; + } smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH; rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov, &err_buftype); + if (rc == -EACCES && retry_without_read_attributes) { + oparms->desired_access &= ~FILE_READ_ATTRIBUTES; + rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov, + &err_buftype); + } if (rc && data) { struct smb2_hdr *hdr = err_iov.iov_base;