diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c
index b204e84b87fb52d938dc138379f7877ffb2ba74a..ac97e0c01d4efaa17c9927525bb2f6f83e812bf2 100644
--- a/fs/cifs/smb2file.c
+++ b/fs/cifs/smb2file.c
@@ -74,7 +74,7 @@ smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
true /* is_fsctl */,
(char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
- NULL, NULL /* no return info */);
+ CIFSMaxBufSize, NULL, NULL /* no return info */);
if (rc == -EOPNOTSUPP) {
cifs_dbg(VFS,
"resiliency not supported by server, disabling\n");
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 7cfafac255aadc157c74b6982e639701e6ba300a..b22be10ee980be7403c2332b426071fc9f4caade 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -581,7 +581,7 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon)
rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
FSCTL_QUERY_NETWORK_INTERFACE_INFO, true /* is_fsctl */,
NULL /* no data input */, 0 /* no data input */,
- (char **)&out_buf, &ret_data_len);
+ CIFSMaxBufSize, (char **)&out_buf, &ret_data_len);
if (rc == -EOPNOTSUPP) {
cifs_dbg(FYI,
"server does not support query network interfaces\n");
@@ -1297,7 +1297,7 @@ SMB2_request_res_key(const unsigned int xid, struct cifs_tcon *tcon,
rc = SMB2_ioctl(xid, tcon, persistent_fid, volatile_fid,
FSCTL_SRV_REQUEST_RESUME_KEY, true /* is_fsctl */,
- NULL, 0 /* no input */,
+ NULL, 0 /* no input */, CIFSMaxBufSize,
(char **)&res_key, &ret_data_len);
if (rc) {
@@ -1402,7 +1402,7 @@ smb2_ioctl_query_info(const unsigned int xid,
rc = SMB2_ioctl_init(tcon, &rqst[1],
COMPOUND_FID, COMPOUND_FID,
qi.info_type, true, NULL,
- 0);
+ 0, CIFSMaxBufSize);
}
} else if (qi.flags == PASSTHRU_QUERY_INFO) {
memset(&qi_iov, 0, sizeof(qi_iov));
@@ -1530,8 +1530,8 @@ smb2_copychunk_range(const unsigned int xid,
rc = SMB2_ioctl(xid, tcon, trgtfile->fid.persistent_fid,
trgtfile->fid.volatile_fid, FSCTL_SRV_COPYCHUNK_WRITE,
true /* is_fsctl */, (char *)pcchunk,
- sizeof(struct copychunk_ioctl), (char **)&retbuf,
- &ret_data_len);
+ sizeof(struct copychunk_ioctl), CIFSMaxBufSize,
+ (char **)&retbuf, &ret_data_len);
if (rc == 0) {
if (ret_data_len !=
sizeof(struct copychunk_ioctl_rsp)) {
@@ -1691,7 +1691,7 @@ static bool smb2_set_sparse(const unsigned int xid, struct cifs_tcon *tcon,
rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
cfile->fid.volatile_fid, FSCTL_SET_SPARSE,
true /* is_fctl */,
- &setsparse, 1, NULL, NULL);
+ &setsparse, 1, CIFSMaxBufSize, NULL, NULL);
if (rc) {
tcon->broken_sparse_sup = true;
cifs_dbg(FYI, "set sparse rc = %d\n", rc);
@@ -1764,7 +1764,7 @@ smb2_duplicate_extents(const unsigned int xid,
true /* is_fsctl */,
(char *)&dup_ext_buf,
sizeof(struct duplicate_extents_to_file),
- NULL,
+ CIFSMaxBufSize, NULL,
&ret_data_len);
if (ret_data_len > 0)
@@ -1799,7 +1799,7 @@ smb3_set_integrity(const unsigned int xid, struct cifs_tcon *tcon,
true /* is_fsctl */,
(char *)&integr_info,
sizeof(struct fsctl_set_integrity_information_req),
- NULL,
+ CIFSMaxBufSize, NULL,
&ret_data_len);
}
@@ -1807,6 +1807,8 @@ smb3_set_integrity(const unsigned int xid, struct cifs_tcon *tcon,
/* GMT Token is @GMT-YYYY.MM.DD-HH.MM.SS Unicode which is 48 bytes + null */
#define GMT_TOKEN_SIZE 50
+#define MIN_SNAPSHOT_ARRAY_SIZE 16 /* See MS-SMB2 section 3.3.5.15.1 */
+
/*
* Input buffer contains (empty) struct smb_snapshot array with size filled in
* For output see struct SRV_SNAPSHOT_ARRAY in MS-SMB2 section 2.2.32.2
@@ -1818,13 +1820,29 @@ smb3_enum_snapshots(const unsigned int xid, struct cifs_tcon *tcon,
char *retbuf = NULL;
unsigned int ret_data_len = 0;
int rc;
+ u32 max_response_size;
struct smb_snapshot_array snapshot_in;
+ if (get_user(ret_data_len, (unsigned int __user *)ioc_buf))
+ return -EFAULT;
+
+ /*
+ * Note that for snapshot queries that servers like Azure expect that
+ * the first query be minimal size (and just used to get the number/size
+ * of previous versions) so response size must be specified as EXACTLY
+ * sizeof(struct snapshot_array) which is 16 when rounded up to multiple
+ * of eight bytes.
+ */
+ if (ret_data_len == 0)
+ max_response_size = MIN_SNAPSHOT_ARRAY_SIZE;
+ else
+ max_response_size = CIFSMaxBufSize;
+
rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
cfile->fid.volatile_fid,
FSCTL_SRV_ENUMERATE_SNAPSHOTS,
true /* is_fsctl */,
- NULL, 0 /* no input data */,
+ NULL, 0 /* no input data */, max_response_size,
(char **)&retbuf,
&ret_data_len);
cifs_dbg(FYI, "enum snaphots ioctl returned %d and ret buflen is %d\n",
@@ -2302,7 +2320,7 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
FSCTL_DFS_GET_REFERRALS,
true /* is_fsctl */,
- (char *)dfs_req, dfs_req_size,
+ (char *)dfs_req, dfs_req_size, CIFSMaxBufSize,
(char **)&dfs_rsp, &dfs_rsp_size);
} while (rc == -EAGAIN);
@@ -2656,7 +2674,8 @@ static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon,
rc = SMB2_ioctl_init(tcon, &rqst[num++], cfile->fid.persistent_fid,
cfile->fid.volatile_fid, FSCTL_SET_ZERO_DATA,
true /* is_fctl */, (char *)&fsctl_buf,
- sizeof(struct file_zero_data_information));
+ sizeof(struct file_zero_data_information),
+ CIFSMaxBufSize);
if (rc)
goto zero_range_exit;
@@ -2733,7 +2752,8 @@ static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon,
rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
cfile->fid.volatile_fid, FSCTL_SET_ZERO_DATA,
true /* is_fctl */, (char *)&fsctl_buf,
- sizeof(struct file_zero_data_information), NULL, NULL);
+ sizeof(struct file_zero_data_information),
+ CIFSMaxBufSize, NULL, NULL);
free_xid(xid);
return rc;
}
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 21ac19ff19cb2c3257f524f4aef90f0de2e8d342..0dc66f36ff5b44dc619e74feba2df351a689e31d 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1002,7 +1002,8 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
- (char *)pneg_inbuf, inbuflen, (char **)&pneg_rsp, &rsplen);
+ (char *)pneg_inbuf, inbuflen, CIFSMaxBufSize,
+ (char **)&pneg_rsp, &rsplen);
if (rc == -EOPNOTSUPP) {
/*
* Old Windows versions or Netapp SMB server can return
@@ -2478,7 +2479,8 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
int
SMB2_ioctl_init(struct cifs_tcon *tcon, struct smb_rqst *rqst,
u64 persistent_fid, u64 volatile_fid, u32 opcode,
- bool is_fsctl, char *in_data, u32 indatalen)
+ bool is_fsctl, char *in_data, u32 indatalen,
+ __u32 max_response_size)
{
struct smb2_ioctl_req *req;
struct kvec *iov = rqst->rq_iov;
@@ -2520,16 +2522,21 @@ SMB2_ioctl_init(struct cifs_tcon *tcon, struct smb_rqst *rqst,
req->OutputCount = 0; /* MBZ */
/*
- * Could increase MaxOutputResponse, but that would require more
- * than one credit. Windows typically sets this smaller, but for some
+ * In most cases max_response_size is set to 16K (CIFSMaxBufSize)
+ * We Could increase default MaxOutputResponse, but that could require
+ * more credits. Windows typically sets this smaller, but for some
* ioctls it may be useful to allow server to send more. No point
* limiting what the server can send as long as fits in one credit
- * Unfortunately - we can not handle more than CIFS_MAX_MSG_SIZE
- * (by default, note that it can be overridden to make max larger)
- * in responses (except for read responses which can be bigger.
- * We may want to bump this limit up
+ * We can not handle more than CIFS_MAX_BUF_SIZE yet but may want
+ * to increase this limit up in the future.
+ * Note that for snapshot queries that servers like Azure expect that
+ * the first query be minimal size (and just used to get the number/size
+ * of previous versions) so response size must be specified as EXACTLY
+ * sizeof(struct snapshot_array) which is 16 when rounded up to multiple
+ * of eight bytes. Currently that is the only case where we set max
+ * response size smaller.
*/
- req->MaxOutputResponse = cpu_to_le32(CIFSMaxBufSize);
+ req->MaxOutputResponse = cpu_to_le32(max_response_size);
if (is_fsctl)
req->Flags = cpu_to_le32(SMB2_0_IOCTL_IS_FSCTL);
@@ -2550,13 +2557,14 @@ SMB2_ioctl_free(struct smb_rqst *rqst)
cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
}
+
/*
* SMB2 IOCTL is used for both IOCTLs and FSCTLs
*/
int
SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
u64 volatile_fid, u32 opcode, bool is_fsctl,
- char *in_data, u32 indatalen,
+ char *in_data, u32 indatalen, u32 max_out_data_len,
char **out_data, u32 *plen /* returned data len */)
{
struct smb_rqst rqst;
@@ -2593,8 +2601,8 @@ SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid,
rqst.rq_iov = iov;
rqst.rq_nvec = SMB2_IOCTL_IOV_SIZE;
- rc = SMB2_ioctl_init(tcon, &rqst, persistent_fid, volatile_fid,
- opcode, is_fsctl, in_data, indatalen);
+ rc = SMB2_ioctl_init(tcon, &rqst, persistent_fid, volatile_fid, opcode,
+ is_fsctl, in_data, indatalen, max_out_data_len);
if (rc)
goto ioctl_exit;
@@ -2672,7 +2680,8 @@ SMB2_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
rc = SMB2_ioctl(xid, tcon, persistent_fid, volatile_fid,
FSCTL_SET_COMPRESSION, true /* is_fsctl */,
(char *)&fsctl_input /* data input */,
- 2 /* in data len */, &ret_data /* out data */, NULL);
+ 2 /* in data len */, CIFSMaxBufSize /* max out data */,
+ &ret_data /* out data */, NULL);
cifs_dbg(FYI, "set compression rc %d\n", rc);
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index 3c32d0cfea69b0c7191336e5b38247de578ed63b..52df125e918984139b176a5f4101ae6da11c7e0f 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -142,11 +142,12 @@ extern int SMB2_open_init(struct cifs_tcon *tcon, struct smb_rqst *rqst,
extern void SMB2_open_free(struct smb_rqst *rqst);
extern int SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon,
u64 persistent_fid, u64 volatile_fid, u32 opcode,
- bool is_fsctl, char *in_data, u32 indatalen,
+ bool is_fsctl, char *in_data, u32 indatalen, u32 maxoutlen,
char **out_data, u32 *plen /* returned data len */);
extern int SMB2_ioctl_init(struct cifs_tcon *tcon, struct smb_rqst *rqst,
u64 persistent_fid, u64 volatile_fid, u32 opcode,
- bool is_fsctl, char *in_data, u32 indatalen);
+ bool is_fsctl, char *in_data, u32 indatalen,
+ __u32 max_response_size);
extern void SMB2_ioctl_free(struct smb_rqst *rqst);
extern int SMB2_close(const unsigned int xid, struct cifs_tcon *tcon,
u64 persistent_file_id, u64 volatile_file_id);