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| author | Ronnie Sahlberg <lsahlber@redhat.com> | 2019-01-29 12:46:17 +1000 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2019-01-29 16:17:25 -0600 |
| commit | c4627e66f73a28c5515b908c90c2bf7120086497 (patch) | |
| tree | 857fafd021a0dda647645574c20b8dc44fe0d945 /fs | |
| parent | 58d15ed1203f4d858c339ea4d7dafa94bd2a56d3 (diff) | |
| download | lwn-c4627e66f73a28c5515b908c90c2bf7120086497.tar.gz lwn-c4627e66f73a28c5515b908c90c2bf7120086497.zip | |
cifs: limit amount of data we request for xattrs to CIFSMaxBufSize
minus the various headers and blobs that will be part of the reply.
or else we might trigger a session reconnect.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/cifs/smb2ops.c | 4 | ||||
| -rw-r--r-- | fs/cifs/smb2pdu.h | 15 |
2 files changed, 16 insertions, 3 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 153238fc4fa9..6f96e2292856 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -866,7 +866,9 @@ smb2_query_eas(const unsigned int xid, struct cifs_tcon *tcon, FILE_READ_EA, FILE_FULL_EA_INFORMATION, SMB2_O_INFO_FILE, - SMB2_MAX_EA_BUF, + CIFSMaxBufSize - + MAX_SMB2_CREATE_RESPONSE_SIZE - + MAX_SMB2_CLOSE_RESPONSE_SIZE, &rsp_iov, &buftype, cifs_sb); if (rc) { /* diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h index e9cc6775df21..538e2299805f 100644 --- a/fs/cifs/smb2pdu.h +++ b/fs/cifs/smb2pdu.h @@ -85,6 +85,7 @@ #define NUMBER_OF_SMB2_COMMANDS 0x0013 /* 52 transform hdr + 64 hdr + 88 create rsp */ +#define SMB2_TRANSFORM_HEADER_SIZE 52 #define MAX_SMB2_HDR_SIZE 204 #define SMB2_PROTO_NUMBER cpu_to_le32(0x424d53fe) @@ -648,6 +649,13 @@ struct smb2_create_req { __u8 Buffer[0]; } __packed; +/* + * Maximum size of a SMB2_CREATE response is 64 (smb2 header) + + * 88 (fixed part of create response) + 520 (path) + 150 (contexts) + + * 2 bytes of padding. + */ +#define MAX_SMB2_CREATE_RESPONSE_SIZE 824 + struct smb2_create_rsp { struct smb2_sync_hdr sync_hdr; __le16 StructureSize; /* Must be 89 */ @@ -996,6 +1004,11 @@ struct smb2_close_req { __u64 VolatileFileId; /* opaque endianness */ } __packed; +/* + * Maximum size of a SMB2_CLOSE response is 64 (smb2 header) + 60 (data) + */ +#define MAX_SMB2_CLOSE_RESPONSE_SIZE 124 + struct smb2_close_rsp { struct smb2_sync_hdr sync_hdr; __le16 StructureSize; /* 60 */ @@ -1398,8 +1411,6 @@ struct smb2_file_link_info { /* encoding of request for level 11 */ char FileName[0]; /* Name to be assigned to new link */ } __packed; /* level 11 Set */ -#define SMB2_MAX_EA_BUF 65536 - struct smb2_file_full_ea_info { /* encoding of response for level 15 */ __le32 next_entry_offset; __u8 flags; |