[next] ksmbd: replace one-element arrays with flexible-array members

Message ID Y3OxronfaPYv9qGP@work
State New
Headers
Series [next] ksmbd: replace one-element arrays with flexible-array members |

Commit Message

Gustavo A. R. Silva Nov. 15, 2022, 3:35 p.m. UTC
  One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element arrays with flexible-array
members in multiple structs in fs/ksmbd/smb_common.h and one in
fs/ksmbd/smb2pdu.h.

Important to mention is that doing a build before/after this patch results
in no binary output differences.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines
on memcpy() and help us make progress towards globally enabling
-fstrict-flex-arrays=3 [1].

Link: https://github.com/KSPP/linux/issues/242
Link: https://github.com/KSPP/linux/issues/79
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 fs/ksmbd/smb2pdu.c    |  4 ++--
 fs/ksmbd/smb2pdu.h    |  2 +-
 fs/ksmbd/smb_common.h | 12 ++++++------
 3 files changed, 9 insertions(+), 9 deletions(-)
  

Comments

Namjae Jeon Nov. 16, 2022, 12:21 a.m. UTC | #1
2022-11-16 0:35 GMT+09:00, Gustavo A. R. Silva <gustavoars@kernel.org>:
> One-element arrays are deprecated, and we are replacing them with flexible
> array members instead. So, replace one-element arrays with flexible-array
> members in multiple structs in fs/ksmbd/smb_common.h and one in
> fs/ksmbd/smb2pdu.h.
>
> Important to mention is that doing a build before/after this patch results
> in no binary output differences.
>
> This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines
> on memcpy() and help us make progress towards globally enabling
> -fstrict-flex-arrays=3 [1].
>
> Link: https://github.com/KSPP/linux/issues/242
> Link: https://github.com/KSPP/linux/issues/79
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html
> [1]
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>

Thanks for your patch!
  
Kees Cook Nov. 16, 2022, 10:24 p.m. UTC | #2
On Tue, Nov 15, 2022 at 09:35:10AM -0600, Gustavo A. R. Silva wrote:
> One-element arrays are deprecated, and we are replacing them with flexible
> array members instead. So, replace one-element arrays with flexible-array
> members in multiple structs in fs/ksmbd/smb_common.h and one in
> fs/ksmbd/smb2pdu.h.
> 
> Important to mention is that doing a build before/after this patch results
> in no binary output differences.
> 
> This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines
> on memcpy() and help us make progress towards globally enabling
> -fstrict-flex-arrays=3 [1].
> 
> Link: https://github.com/KSPP/linux/issues/242
> Link: https://github.com/KSPP/linux/issues/79
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Reviewed-by: Kees Cook <keescook@chromium.org>
  
Sergey Senozhatsky Nov. 17, 2022, 12:35 a.m. UTC | #3
On (22/11/15 09:35), Gustavo A. R. Silva wrote:
> One-element arrays are deprecated, and we are replacing them with flexible
> array members instead. So, replace one-element arrays with flexible-array
> members in multiple structs in fs/ksmbd/smb_common.h and one in
> fs/ksmbd/smb2pdu.h.
> 
> Important to mention is that doing a build before/after this patch results
> in no binary output differences.
> 
> This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines
> on memcpy() and help us make progress towards globally enabling
> -fstrict-flex-arrays=3 [1].
> 
> Link: https://github.com/KSPP/linux/issues/242
> Link: https://github.com/KSPP/linux/issues/79
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
  

Patch

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 9306e10753f9..ae7a3b000c61 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -3438,7 +3438,7 @@  static int smb2_populate_readdir_entry(struct ksmbd_conn *conn, int info_level,
 		goto free_conv_name;
 	}
 
-	struct_sz = readdir_info_level_struct_sz(info_level) - 1 + conv_len;
+	struct_sz = readdir_info_level_struct_sz(info_level) + conv_len;
 	next_entry_offset = ALIGN(struct_sz, KSMBD_DIR_INFO_ALIGNMENT);
 	d_info->last_entry_off_align = next_entry_offset - struct_sz;
 
@@ -3690,7 +3690,7 @@  static int reserve_populate_dentry(struct ksmbd_dir_info *d_info,
 		return -EOPNOTSUPP;
 
 	conv_len = (d_info->name_len + 1) * 2;
-	next_entry_offset = ALIGN(struct_sz - 1 + conv_len,
+	next_entry_offset = ALIGN(struct_sz + conv_len,
 				  KSMBD_DIR_INFO_ALIGNMENT);
 
 	if (next_entry_offset > d_info->out_buf_len) {
diff --git a/fs/ksmbd/smb2pdu.h b/fs/ksmbd/smb2pdu.h
index 092fdd3f8750..aa5dbe54f5a1 100644
--- a/fs/ksmbd/smb2pdu.h
+++ b/fs/ksmbd/smb2pdu.h
@@ -443,7 +443,7 @@  struct smb2_posix_info {
 	/* SidBuffer contain two sids (UNIX user sid(16), UNIX group sid(16)) */
 	u8 SidBuffer[32];
 	__le32 name_len;
-	u8 name[1];
+	u8 name[];
 	/*
 	 * var sized owner SID
 	 * var sized group SID
diff --git a/fs/ksmbd/smb_common.h b/fs/ksmbd/smb_common.h
index 318c16fa81da..e663ab9ea759 100644
--- a/fs/ksmbd/smb_common.h
+++ b/fs/ksmbd/smb_common.h
@@ -277,14 +277,14 @@  struct file_directory_info {
 	__le64 AllocationSize;
 	__le32 ExtFileAttributes;
 	__le32 FileNameLength;
-	char FileName[1];
+	char FileName[];
 } __packed;   /* level 0x101 FF resp data */
 
 struct file_names_info {
 	__le32 NextEntryOffset;
 	__u32 FileIndex;
 	__le32 FileNameLength;
-	char FileName[1];
+	char FileName[];
 } __packed;   /* level 0xc FF resp data */
 
 struct file_full_directory_info {
@@ -299,7 +299,7 @@  struct file_full_directory_info {
 	__le32 ExtFileAttributes;
 	__le32 FileNameLength;
 	__le32 EaSize;
-	char FileName[1];
+	char FileName[];
 } __packed; /* level 0x102 FF resp */
 
 struct file_both_directory_info {
@@ -317,7 +317,7 @@  struct file_both_directory_info {
 	__u8   ShortNameLength;
 	__u8   Reserved;
 	__u8   ShortName[24];
-	char FileName[1];
+	char FileName[];
 } __packed; /* level 0x104 FFrsp data */
 
 struct file_id_both_directory_info {
@@ -337,7 +337,7 @@  struct file_id_both_directory_info {
 	__u8   ShortName[24];
 	__le16 Reserved2;
 	__le64 UniqueId;
-	char FileName[1];
+	char FileName[];
 } __packed;
 
 struct file_id_full_dir_info {
@@ -354,7 +354,7 @@  struct file_id_full_dir_info {
 	__le32 EaSize; /* EA size */
 	__le32 Reserved;
 	__le64 UniqueId; /* inode num - le since Samba puts ino in low 32 bit*/
-	char FileName[1];
+	char FileName[];
 } __packed; /* level 0x105 FF rsp data */
 
 struct smb_version_values {