| Message ID | 20230214215446.never.567-kees@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | smb3: Replace smb2pdu 1-element arrays with flex-arrays | expand |
This seems to have a lot of conflicts with for-next (doesn't apply). Any chance you could rebase it on linux-next On Tue, Feb 14, 2023 at 3:57 PM Kees Cook <keescook@chromium.org> wrote: > > The kernel is globally removing the ambiguous 0-length and 1-element > arrays in favor of flexible arrays, so that we can gain both compile-time > and run-time array bounds checking[1]. > > Replace the trailing 1-element array with a flexible array in the > following structures: > > struct smb2_err_rsp > struct smb2_tree_connect_req > struct smb2_negotiate_rsp > struct smb2_sess_setup_req > struct smb2_sess_setup_rsp > struct smb2_read_req > struct smb2_read_rsp > struct smb2_write_req > struct smb2_write_rsp > struct smb2_query_directory_req > struct smb2_query_directory_rsp > struct smb2_set_info_req > struct smb2_change_notify_rsp > struct smb2_create_rsp > struct smb2_query_info_req > struct smb2_query_info_rsp > > Replace the trailing 1-element array with a flexible array, but leave > the existing structure padding: > > struct smb2_file_all_info > struct smb2_lock_req > > Adjust all related size calculations to match the changes to sizeof(). > > No machine code output differences are produced after these changes. > > [1] For lots of details, see both: > https://docs.kernel.org/process/deprecated.html#zero-length-and-one-element-arrays > https://people.kernel.org/kees/bounded-flexible-arrays-in-c > > Cc: Steve French <sfrench@samba.org> > Cc: Paulo Alcantara <pc@cjr.nz> > Cc: Ronnie Sahlberg <lsahlber@redhat.com> > Cc: Shyam Prasad N <sprasad@microsoft.com> > Cc: Tom Talpey <tom@talpey.com> > Cc: Namjae Jeon <linkinjeon@kernel.org> > Cc: Sergey Senozhatsky <senozhatsky@chromium.org> > Cc: Gustavo A. R. Silva <gustavoars@kernel.org> > Cc: linux-cifs@vger.kernel.org > Cc: samba-technical@lists.samba.org > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > fs/cifs/smb2file.c | 2 +- > fs/cifs/smb2misc.c | 2 +- > fs/cifs/smb2pdu.c | 16 +++++++-------- > fs/cifs/smb2pdu.h | 2 +- > fs/ksmbd/smb2pdu.c | 6 ++---- > fs/smbfs_common/smb2pdu.h | 42 ++++++++++++++++++++++----------------- > 6 files changed, 36 insertions(+), 34 deletions(-) > > diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c > index 9f1dd04b555a..e0ee96d69d49 100644 > --- a/fs/cifs/smb2file.c > +++ b/fs/cifs/smb2file.c > @@ -35,7 +35,7 @@ static struct smb2_symlink_err_rsp *symlink_data(const struct kvec *iov) > len = (u32)err->ErrorContextCount * (offsetof(struct smb2_error_context_rsp, > ErrorContextData) + > sizeof(struct smb2_symlink_err_rsp)); > - if (le32_to_cpu(err->ByteCount) < len || iov->iov_len < len + sizeof(*err)) > + if (le32_to_cpu(err->ByteCount) < len || iov->iov_len < len + sizeof(*err) + 1) > return ERR_PTR(-EINVAL); > > p = (struct smb2_error_context_rsp *)err->ErrorData; > diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c > index 572293c18e16..3935a60db5c3 100644 > --- a/fs/cifs/smb2misc.c > +++ b/fs/cifs/smb2misc.c > @@ -113,7 +113,7 @@ static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len, > } else if (nc_offset + 1 == non_ctxlen) { > cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n"); > size_of_pad_before_neg_ctxts = 0; > - } else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE) > + } else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1) > /* has padding, but no SPNEGO blob */ > size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1; > else > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c > index c5cb2639b3f1..22145e7e08f6 100644 > --- a/fs/cifs/smb2pdu.c > +++ b/fs/cifs/smb2pdu.c > @@ -1373,7 +1373,7 @@ SMB2_sess_sendreceive(struct SMB2_sess_data *sess_data) > > /* Testing shows that buffer offset must be at location of Buffer[0] */ > req->SecurityBufferOffset = > - cpu_to_le16(sizeof(struct smb2_sess_setup_req) - 1 /* pad */); > + cpu_to_le16(sizeof(struct smb2_sess_setup_req)); > req->SecurityBufferLength = cpu_to_le16(sess_data->iov[1].iov_len); > > memset(&rqst, 0, sizeof(struct smb_rqst)); > @@ -1892,8 +1892,7 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree, > iov[0].iov_len = total_len - 1; > > /* Testing shows that buffer offset must be at location of Buffer[0] */ > - req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req) > - - 1 /* pad */); > + req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req)); > req->PathLength = cpu_to_le16(unc_path_len - 2); > iov[1].iov_base = unc_path; > iov[1].iov_len = unc_path_len; > @@ -3773,7 +3772,7 @@ SMB2_change_notify(const unsigned int xid, struct cifs_tcon *tcon, > ses->Suid, (u8)watch_tree, completion_filter); > /* validate that notify information is plausible */ > if ((rsp_iov.iov_base == NULL) || > - (rsp_iov.iov_len < sizeof(struct smb2_change_notify_rsp))) > + (rsp_iov.iov_len < sizeof(struct smb2_change_notify_rsp) + 1)) > goto cnotify_exit; > > smb_rsp = (struct smb2_change_notify_rsp *)rsp_iov.iov_base; > @@ -4966,7 +4965,7 @@ int SMB2_query_directory_init(const unsigned int xid, > memcpy(bufptr, &asteriks, len); > > req->FileNameOffset = > - cpu_to_le16(sizeof(struct smb2_query_directory_req) - 1); > + cpu_to_le16(sizeof(struct smb2_query_directory_req)); > req->FileNameLength = cpu_to_le16(len); > /* > * BB could be 30 bytes or so longer if we used SMB2 specific > @@ -5162,8 +5161,7 @@ SMB2_set_info_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server, > req->VolatileFileId = volatile_fid; > req->AdditionalInformation = cpu_to_le32(additional_info); > > - req->BufferOffset = > - cpu_to_le16(sizeof(struct smb2_set_info_req) - 1); > + req->BufferOffset = cpu_to_le16(sizeof(struct smb2_set_info_req)); > req->BufferLength = cpu_to_le32(*size); > > memcpy(req->Buffer, *data, *size); > @@ -5397,9 +5395,9 @@ build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, > req->VolatileFileId = volatile_fid; > /* 1 for pad */ > req->InputBufferOffset = > - cpu_to_le16(sizeof(struct smb2_query_info_req) - 1); > + cpu_to_le16(sizeof(struct smb2_query_info_req)); > req->OutputBufferLength = cpu_to_le32( > - outbuf_len + sizeof(struct smb2_query_info_rsp) - 1); > + outbuf_len + sizeof(struct smb2_query_info_rsp)); > > iov->iov_base = (char *)req; > iov->iov_len = total_len; > diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h > index 1237bb86e93a..a5773a06aba8 100644 > --- a/fs/cifs/smb2pdu.h > +++ b/fs/cifs/smb2pdu.h > @@ -57,7 +57,7 @@ struct smb2_rdma_crypto_transform { > #define COMPOUND_FID 0xFFFFFFFFFFFFFFFFULL > > #define SMB2_SYMLINK_STRUCT_SIZE \ > - (sizeof(struct smb2_err_rsp) - 1 + sizeof(struct smb2_symlink_err_rsp)) > + (sizeof(struct smb2_err_rsp) + sizeof(struct smb2_symlink_err_rsp)) > > #define SYMLINK_ERROR_TAG 0x4c4d5953 > > diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c > index 619857af0cc2..aef72077fc75 100644 > --- a/fs/ksmbd/smb2pdu.c > +++ b/fs/ksmbd/smb2pdu.c > @@ -274,8 +274,7 @@ int init_smb2_neg_rsp(struct ksmbd_work *work) > le16_to_cpu(rsp->SecurityBufferOffset)); > inc_rfc1001_len(work->response_buf, > sizeof(struct smb2_negotiate_rsp) - > - sizeof(struct smb2_hdr) - sizeof(rsp->Buffer) + > - AUTH_GSS_LENGTH); > + sizeof(struct smb2_hdr) + AUTH_GSS_LENGTH); > rsp->SecurityMode = SMB2_NEGOTIATE_SIGNING_ENABLED_LE; > if (server_conf.signing == KSMBD_CONFIG_OPT_MANDATORY) > rsp->SecurityMode |= SMB2_NEGOTIATE_SIGNING_REQUIRED_LE; > @@ -1205,8 +1204,7 @@ int smb2_handle_negotiate(struct ksmbd_work *work) > ksmbd_copy_gss_neg_header((char *)(&rsp->hdr) + > le16_to_cpu(rsp->SecurityBufferOffset)); > inc_rfc1001_len(work->response_buf, sizeof(struct smb2_negotiate_rsp) - > - sizeof(struct smb2_hdr) - sizeof(rsp->Buffer) + > - AUTH_GSS_LENGTH); > + sizeof(struct smb2_hdr) + AUTH_GSS_LENGTH); > rsp->SecurityMode = SMB2_NEGOTIATE_SIGNING_ENABLED_LE; > conn->use_spnego = true; > > diff --git a/fs/smbfs_common/smb2pdu.h b/fs/smbfs_common/smb2pdu.h > index 7d605db3bb3b..ace133cf6072 100644 > --- a/fs/smbfs_common/smb2pdu.h > +++ b/fs/smbfs_common/smb2pdu.h > @@ -167,7 +167,7 @@ struct smb2_err_rsp { > __u8 ErrorContextCount; > __u8 Reserved; > __le32 ByteCount; /* even if zero, at least one byte follows */ > - __u8 ErrorData[1]; /* variable length */ > + __u8 ErrorData[]; /* variable length */ > } __packed; > > #define SMB3_AES_CCM_NONCE 11 > @@ -308,7 +308,7 @@ struct smb2_tree_connect_req { > __le16 Flags; /* Flags in SMB3.1.1 */ > __le16 PathOffset; > __le16 PathLength; > - __u8 Buffer[1]; /* variable length */ > + __u8 Buffer[]; /* variable length */ > } __packed; > > /* Possible ShareType values */ > @@ -595,7 +595,7 @@ struct smb2_negotiate_rsp { > __le16 SecurityBufferOffset; > __le16 SecurityBufferLength; > __le32 NegotiateContextOffset; /* Pre:SMB3.1.1 was reserved/ignored */ > - __u8 Buffer[1]; /* variable length GSS security buffer */ > + __u8 Buffer[]; /* variable length GSS security buffer */ > } __packed; > > > @@ -616,7 +616,7 @@ struct smb2_sess_setup_req { > __le16 SecurityBufferOffset; > __le16 SecurityBufferLength; > __le64 PreviousSessionId; > - __u8 Buffer[1]; /* variable length GSS security buffer */ > + __u8 Buffer[]; /* variable length GSS security buffer */ > } __packed; > > /* Currently defined SessionFlags */ > @@ -633,7 +633,7 @@ struct smb2_sess_setup_rsp { > __le16 SessionFlags; > __le16 SecurityBufferOffset; > __le16 SecurityBufferLength; > - __u8 Buffer[1]; /* variable length GSS security buffer */ > + __u8 Buffer[]; /* variable length GSS security buffer */ > } __packed; > > > @@ -715,7 +715,7 @@ struct smb2_read_req { > __le32 RemainingBytes; > __le16 ReadChannelInfoOffset; > __le16 ReadChannelInfoLength; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > /* Read flags */ > @@ -730,7 +730,7 @@ struct smb2_read_rsp { > __le32 DataLength; > __le32 DataRemaining; > __le32 Flags; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > > @@ -754,7 +754,7 @@ struct smb2_write_req { > __le16 WriteChannelInfoOffset; > __le16 WriteChannelInfoLength; > __le32 Flags; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > struct smb2_write_rsp { > @@ -765,7 +765,7 @@ struct smb2_write_rsp { > __le32 DataLength; > __le32 DataRemaining; > __u32 Reserved2; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > > @@ -812,7 +812,10 @@ struct smb2_lock_req { > __u64 PersistentFileId; > __u64 VolatileFileId; > /* Followed by at least one */ > - struct smb2_lock_element locks[1]; > + union { > + struct smb2_lock_element lock; > + DECLARE_FLEX_ARRAY(struct smb2_lock_element, locks); > + }; > } __packed; > > struct smb2_lock_rsp { > @@ -866,7 +869,7 @@ struct smb2_query_directory_req { > __le16 FileNameOffset; > __le16 FileNameLength; > __le32 OutputBufferLength; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > struct smb2_query_directory_rsp { > @@ -874,7 +877,7 @@ struct smb2_query_directory_rsp { > __le16 StructureSize; /* Must be 9 */ > __le16 OutputBufferOffset; > __le32 OutputBufferLength; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > /* > @@ -897,7 +900,7 @@ struct smb2_set_info_req { > __le32 AdditionalInformation; > __u64 PersistentFileId; > __u64 VolatileFileId; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > struct smb2_set_info_rsp { > @@ -952,7 +955,7 @@ struct smb2_change_notify_rsp { > __le16 StructureSize; /* Must be 9 */ > __le16 OutputBufferOffset; > __le32 OutputBufferLength; > - __u8 Buffer[1]; /* array of file notify structs */ > + __u8 Buffer[]; /* array of file notify structs */ > } __packed; > > > @@ -1158,7 +1161,7 @@ struct smb2_create_rsp { > __u64 VolatileFileId; > __le32 CreateContextsOffset; > __le32 CreateContextsLength; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > struct create_posix { > @@ -1501,7 +1504,7 @@ struct smb2_query_info_req { > __le32 Flags; > __u64 PersistentFileId; > __u64 VolatileFileId; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > struct smb2_query_info_rsp { > @@ -1509,7 +1512,7 @@ struct smb2_query_info_rsp { > __le16 StructureSize; /* Must be 9 */ > __le16 OutputBufferOffset; > __le32 OutputBufferLength; > - __u8 Buffer[1]; > + __u8 Buffer[]; > } __packed; > > /* > @@ -1570,7 +1573,10 @@ struct smb2_file_all_info { /* data block encoding of response to level 18 */ > __le32 Mode; > __le32 AlignmentRequirement; > __le32 FileNameLength; > - char FileName[1]; > + union { > + char __pad; /* Legacy structure padding */ > + DECLARE_FLEX_ARRAY(char, FileName); > + }; > } __packed; /* level 18 Query */ > > struct smb2_file_eof_info { /* encoding of request for level 10 */ > -- > 2.34.1 >
On Tue, Feb 14, 2023 at 04:53:10PM -0600, Steve French wrote: > This seems to have a lot of conflicts with for-next (doesn't apply). > Any chance you could rebase it on linux-next Ah, dang. I was working off of 20230203. I will rebase! Sorry for the noise. :)
diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c index 9f1dd04b555a..e0ee96d69d49 100644 --- a/fs/cifs/smb2file.c +++ b/fs/cifs/smb2file.c @@ -35,7 +35,7 @@ static struct smb2_symlink_err_rsp *symlink_data(const struct kvec *iov) len = (u32)err->ErrorContextCount * (offsetof(struct smb2_error_context_rsp, ErrorContextData) + sizeof(struct smb2_symlink_err_rsp)); - if (le32_to_cpu(err->ByteCount) < len || iov->iov_len < len + sizeof(*err)) + if (le32_to_cpu(err->ByteCount) < len || iov->iov_len < len + sizeof(*err) + 1) return ERR_PTR(-EINVAL); p = (struct smb2_error_context_rsp *)err->ErrorData; diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index 572293c18e16..3935a60db5c3 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -113,7 +113,7 @@ static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len, } else if (nc_offset + 1 == non_ctxlen) { cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n"); size_of_pad_before_neg_ctxts = 0; - } else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE) + } else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1) /* has padding, but no SPNEGO blob */ size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1; else diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index c5cb2639b3f1..22145e7e08f6 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1373,7 +1373,7 @@ SMB2_sess_sendreceive(struct SMB2_sess_data *sess_data) /* Testing shows that buffer offset must be at location of Buffer[0] */ req->SecurityBufferOffset = - cpu_to_le16(sizeof(struct smb2_sess_setup_req) - 1 /* pad */); + cpu_to_le16(sizeof(struct smb2_sess_setup_req)); req->SecurityBufferLength = cpu_to_le16(sess_data->iov[1].iov_len); memset(&rqst, 0, sizeof(struct smb_rqst)); @@ -1892,8 +1892,7 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree, iov[0].iov_len = total_len - 1; /* Testing shows that buffer offset must be at location of Buffer[0] */ - req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req) - - 1 /* pad */); + req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req)); req->PathLength = cpu_to_le16(unc_path_len - 2); iov[1].iov_base = unc_path; iov[1].iov_len = unc_path_len; @@ -3773,7 +3772,7 @@ SMB2_change_notify(const unsigned int xid, struct cifs_tcon *tcon, ses->Suid, (u8)watch_tree, completion_filter); /* validate that notify information is plausible */ if ((rsp_iov.iov_base == NULL) || - (rsp_iov.iov_len < sizeof(struct smb2_change_notify_rsp))) + (rsp_iov.iov_len < sizeof(struct smb2_change_notify_rsp) + 1)) goto cnotify_exit; smb_rsp = (struct smb2_change_notify_rsp *)rsp_iov.iov_base; @@ -4966,7 +4965,7 @@ int SMB2_query_directory_init(const unsigned int xid, memcpy(bufptr, &asteriks, len); req->FileNameOffset = - cpu_to_le16(sizeof(struct smb2_query_directory_req) - 1); + cpu_to_le16(sizeof(struct smb2_query_directory_req)); req->FileNameLength = cpu_to_le16(len); /* * BB could be 30 bytes or so longer if we used SMB2 specific @@ -5162,8 +5161,7 @@ SMB2_set_info_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server, req->VolatileFileId = volatile_fid; req->AdditionalInformation = cpu_to_le32(additional_info); - req->BufferOffset = - cpu_to_le16(sizeof(struct smb2_set_info_req) - 1); + req->BufferOffset = cpu_to_le16(sizeof(struct smb2_set_info_req)); req->BufferLength = cpu_to_le32(*size); memcpy(req->Buffer, *data, *size); @@ -5397,9 +5395,9 @@ build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, req->VolatileFileId = volatile_fid; /* 1 for pad */ req->InputBufferOffset = - cpu_to_le16(sizeof(struct smb2_query_info_req) - 1); + cpu_to_le16(sizeof(struct smb2_query_info_req)); req->OutputBufferLength = cpu_to_le32( - outbuf_len + sizeof(struct smb2_query_info_rsp) - 1); + outbuf_len + sizeof(struct smb2_query_info_rsp)); iov->iov_base = (char *)req; iov->iov_len = total_len; diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h index 1237bb86e93a..a5773a06aba8 100644 --- a/fs/cifs/smb2pdu.h +++ b/fs/cifs/smb2pdu.h @@ -57,7 +57,7 @@ struct smb2_rdma_crypto_transform { #define COMPOUND_FID 0xFFFFFFFFFFFFFFFFULL #define SMB2_SYMLINK_STRUCT_SIZE \ - (sizeof(struct smb2_err_rsp) - 1 + sizeof(struct smb2_symlink_err_rsp)) + (sizeof(struct smb2_err_rsp) + sizeof(struct smb2_symlink_err_rsp)) #define SYMLINK_ERROR_TAG 0x4c4d5953 diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 619857af0cc2..aef72077fc75 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -274,8 +274,7 @@ int init_smb2_neg_rsp(struct ksmbd_work *work) le16_to_cpu(rsp->SecurityBufferOffset)); inc_rfc1001_len(work->response_buf, sizeof(struct smb2_negotiate_rsp) - - sizeof(struct smb2_hdr) - sizeof(rsp->Buffer) + - AUTH_GSS_LENGTH); + sizeof(struct smb2_hdr) + AUTH_GSS_LENGTH); rsp->SecurityMode = SMB2_NEGOTIATE_SIGNING_ENABLED_LE; if (server_conf.signing == KSMBD_CONFIG_OPT_MANDATORY) rsp->SecurityMode |= SMB2_NEGOTIATE_SIGNING_REQUIRED_LE; @@ -1205,8 +1204,7 @@ int smb2_handle_negotiate(struct ksmbd_work *work) ksmbd_copy_gss_neg_header((char *)(&rsp->hdr) + le16_to_cpu(rsp->SecurityBufferOffset)); inc_rfc1001_len(work->response_buf, sizeof(struct smb2_negotiate_rsp) - - sizeof(struct smb2_hdr) - sizeof(rsp->Buffer) + - AUTH_GSS_LENGTH); + sizeof(struct smb2_hdr) + AUTH_GSS_LENGTH); rsp->SecurityMode = SMB2_NEGOTIATE_SIGNING_ENABLED_LE; conn->use_spnego = true; diff --git a/fs/smbfs_common/smb2pdu.h b/fs/smbfs_common/smb2pdu.h index 7d605db3bb3b..ace133cf6072 100644 --- a/fs/smbfs_common/smb2pdu.h +++ b/fs/smbfs_common/smb2pdu.h @@ -167,7 +167,7 @@ struct smb2_err_rsp { __u8 ErrorContextCount; __u8 Reserved; __le32 ByteCount; /* even if zero, at least one byte follows */ - __u8 ErrorData[1]; /* variable length */ + __u8 ErrorData[]; /* variable length */ } __packed; #define SMB3_AES_CCM_NONCE 11 @@ -308,7 +308,7 @@ struct smb2_tree_connect_req { __le16 Flags; /* Flags in SMB3.1.1 */ __le16 PathOffset; __le16 PathLength; - __u8 Buffer[1]; /* variable length */ + __u8 Buffer[]; /* variable length */ } __packed; /* Possible ShareType values */ @@ -595,7 +595,7 @@ struct smb2_negotiate_rsp { __le16 SecurityBufferOffset; __le16 SecurityBufferLength; __le32 NegotiateContextOffset; /* Pre:SMB3.1.1 was reserved/ignored */ - __u8 Buffer[1]; /* variable length GSS security buffer */ + __u8 Buffer[]; /* variable length GSS security buffer */ } __packed; @@ -616,7 +616,7 @@ struct smb2_sess_setup_req { __le16 SecurityBufferOffset; __le16 SecurityBufferLength; __le64 PreviousSessionId; - __u8 Buffer[1]; /* variable length GSS security buffer */ + __u8 Buffer[]; /* variable length GSS security buffer */ } __packed; /* Currently defined SessionFlags */ @@ -633,7 +633,7 @@ struct smb2_sess_setup_rsp { __le16 SessionFlags; __le16 SecurityBufferOffset; __le16 SecurityBufferLength; - __u8 Buffer[1]; /* variable length GSS security buffer */ + __u8 Buffer[]; /* variable length GSS security buffer */ } __packed; @@ -715,7 +715,7 @@ struct smb2_read_req { __le32 RemainingBytes; __le16 ReadChannelInfoOffset; __le16 ReadChannelInfoLength; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; /* Read flags */ @@ -730,7 +730,7 @@ struct smb2_read_rsp { __le32 DataLength; __le32 DataRemaining; __le32 Flags; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; @@ -754,7 +754,7 @@ struct smb2_write_req { __le16 WriteChannelInfoOffset; __le16 WriteChannelInfoLength; __le32 Flags; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; struct smb2_write_rsp { @@ -765,7 +765,7 @@ struct smb2_write_rsp { __le32 DataLength; __le32 DataRemaining; __u32 Reserved2; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; @@ -812,7 +812,10 @@ struct smb2_lock_req { __u64 PersistentFileId; __u64 VolatileFileId; /* Followed by at least one */ - struct smb2_lock_element locks[1]; + union { + struct smb2_lock_element lock; + DECLARE_FLEX_ARRAY(struct smb2_lock_element, locks); + }; } __packed; struct smb2_lock_rsp { @@ -866,7 +869,7 @@ struct smb2_query_directory_req { __le16 FileNameOffset; __le16 FileNameLength; __le32 OutputBufferLength; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; struct smb2_query_directory_rsp { @@ -874,7 +877,7 @@ struct smb2_query_directory_rsp { __le16 StructureSize; /* Must be 9 */ __le16 OutputBufferOffset; __le32 OutputBufferLength; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; /* @@ -897,7 +900,7 @@ struct smb2_set_info_req { __le32 AdditionalInformation; __u64 PersistentFileId; __u64 VolatileFileId; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; struct smb2_set_info_rsp { @@ -952,7 +955,7 @@ struct smb2_change_notify_rsp { __le16 StructureSize; /* Must be 9 */ __le16 OutputBufferOffset; __le32 OutputBufferLength; - __u8 Buffer[1]; /* array of file notify structs */ + __u8 Buffer[]; /* array of file notify structs */ } __packed; @@ -1158,7 +1161,7 @@ struct smb2_create_rsp { __u64 VolatileFileId; __le32 CreateContextsOffset; __le32 CreateContextsLength; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; struct create_posix { @@ -1501,7 +1504,7 @@ struct smb2_query_info_req { __le32 Flags; __u64 PersistentFileId; __u64 VolatileFileId; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; struct smb2_query_info_rsp { @@ -1509,7 +1512,7 @@ struct smb2_query_info_rsp { __le16 StructureSize; /* Must be 9 */ __le16 OutputBufferOffset; __le32 OutputBufferLength; - __u8 Buffer[1]; + __u8 Buffer[]; } __packed; /* @@ -1570,7 +1573,10 @@ struct smb2_file_all_info { /* data block encoding of response to level 18 */ __le32 Mode; __le32 AlignmentRequirement; __le32 FileNameLength; - char FileName[1]; + union { + char __pad; /* Legacy structure padding */ + DECLARE_FLEX_ARRAY(char, FileName); + }; } __packed; /* level 18 Query */ struct smb2_file_eof_info { /* encoding of request for level 10 */
The kernel is globally removing the ambiguous 0-length and 1-element arrays in favor of flexible arrays, so that we can gain both compile-time and run-time array bounds checking[1]. Replace the trailing 1-element array with a flexible array in the following structures: struct smb2_err_rsp struct smb2_tree_connect_req struct smb2_negotiate_rsp struct smb2_sess_setup_req struct smb2_sess_setup_rsp struct smb2_read_req struct smb2_read_rsp struct smb2_write_req struct smb2_write_rsp struct smb2_query_directory_req struct smb2_query_directory_rsp struct smb2_set_info_req struct smb2_change_notify_rsp struct smb2_create_rsp struct smb2_query_info_req struct smb2_query_info_rsp Replace the trailing 1-element array with a flexible array, but leave the existing structure padding: struct smb2_file_all_info struct smb2_lock_req Adjust all related size calculations to match the changes to sizeof(). No machine code output differences are produced after these changes. [1] For lots of details, see both: https://docs.kernel.org/process/deprecated.html#zero-length-and-one-element-arrays https://people.kernel.org/kees/bounded-flexible-arrays-in-c Cc: Steve French <sfrench@samba.org> Cc: Paulo Alcantara <pc@cjr.nz> Cc: Ronnie Sahlberg <lsahlber@redhat.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Signed-off-by: Kees Cook <keescook@chromium.org> --- fs/cifs/smb2file.c | 2 +- fs/cifs/smb2misc.c | 2 +- fs/cifs/smb2pdu.c | 16 +++++++-------- fs/cifs/smb2pdu.h | 2 +- fs/ksmbd/smb2pdu.c | 6 ++---- fs/smbfs_common/smb2pdu.h | 42 ++++++++++++++++++++++----------------- 6 files changed, 36 insertions(+), 34 deletions(-)