* [PATCH] cifs: Avoid field over-reading memcpy()
@ 2021-06-21 21:44 Kees Cook
2021-06-22 2:40 ` Steve French
0 siblings, 1 reply; 2+ messages in thread
From: Kees Cook @ 2021-06-21 21:44 UTC (permalink / raw)
To: Steve French
Cc: Kees Cook, linux-kernel, linux-cifs, samba-technical, linux-hardening
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally reading across neighboring fields.
Instead of using memcpy to read across multiple struct members, just
perform per-member assignments as already done for other members.
Signed-off-by: Kees Cook <keescook@chromium.org>
---
fs/cifs/smb2pdu.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 31784e3fa96f..962826dc3316 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2892,7 +2892,10 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
#endif /* CIFS_DEBUG2 */
if (buf) {
- memcpy(buf, &rsp->CreationTime, 32);
+ buf->CreationTime = rsp->CreationTime;
+ buf->LastAccessTime = rsp->LastAccessTime;
+ buf->LastWriteTime = rsp->LastWriteTime;
+ buf->ChangeTime = rsp->ChangeTime;
buf->AllocationSize = rsp->AllocationSize;
buf->EndOfFile = rsp->EndofFile;
buf->Attributes = rsp->FileAttributes;
--
2.30.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] cifs: Avoid field over-reading memcpy()
2021-06-21 21:44 [PATCH] cifs: Avoid field over-reading memcpy() Kees Cook
@ 2021-06-22 2:40 ` Steve French
0 siblings, 0 replies; 2+ messages in thread
From: Steve French @ 2021-06-22 2:40 UTC (permalink / raw)
To: Kees Cook; +Cc: Steve French, LKML, CIFS, samba-technical, linux-hardening
merged into cifs-2.6.git for-next
On Mon, Jun 21, 2021 at 4:45 PM Kees Cook <keescook@chromium.org> wrote:
>
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memcpy(), memmove(), and memset(), avoid
> intentionally reading across neighboring fields.
>
> Instead of using memcpy to read across multiple struct members, just
> perform per-member assignments as already done for other members.
>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> fs/cifs/smb2pdu.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 31784e3fa96f..962826dc3316 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -2892,7 +2892,10 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
> #endif /* CIFS_DEBUG2 */
>
> if (buf) {
> - memcpy(buf, &rsp->CreationTime, 32);
> + buf->CreationTime = rsp->CreationTime;
> + buf->LastAccessTime = rsp->LastAccessTime;
> + buf->LastWriteTime = rsp->LastWriteTime;
> + buf->ChangeTime = rsp->ChangeTime;
> buf->AllocationSize = rsp->AllocationSize;
> buf->EndOfFile = rsp->EndofFile;
> buf->Attributes = rsp->FileAttributes;
> --
> 2.30.2
>
--
Thanks,
Steve
^ permalink raw reply [flat|nested] 2+ messages in thread
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