* [PATCH][next] smb: smb2pdu.h: Use static_assert() to check struct sizes
@ 2024-08-08 22:04 Gustavo A. R. Silva
2024-08-09 2:51 ` Namjae Jeon
0 siblings, 1 reply; 3+ messages in thread
From: Gustavo A. R. Silva @ 2024-08-08 22:04 UTC (permalink / raw)
To: Namjae Jeon, Steve French, Sergey Senozhatsky, Tom Talpey,
Paulo Alcantara, Ronnie Sahlberg, Shyam Prasad N, Bharath SM
Cc: linux-cifs, samba-technical, linux-kernel, Gustavo A. R. Silva,
linux-hardening
Commit 9f9bef9bc5c6 ("smb: smb2pdu.h: Avoid -Wflex-array-member-not-at-end
warnings") introduced tagged `struct create_context_hdr`. We want to
ensure that when new members need to be added to the flexible structure,
they are always included within this tagged struct.
So, we use `static_assert()` to ensure that the memory layout for
both the flexible structure and the tagged struct is the same after
any changes.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
fs/smb/common/smb2pdu.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/smb/common/smb2pdu.h b/fs/smb/common/smb2pdu.h
index c3ee42188d25..c769f9dbc0b4 100644
--- a/fs/smb/common/smb2pdu.h
+++ b/fs/smb/common/smb2pdu.h
@@ -1216,6 +1216,8 @@ struct create_context {
);
__u8 Buffer[];
} __packed;
+static_assert(offsetof(struct create_context, Buffer) == sizeof(struct create_context_hdr),
+ "struct member likely outside of __struct_group()");
struct smb2_create_req {
struct smb2_hdr hdr;
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH][next] smb: smb2pdu.h: Use static_assert() to check struct sizes
2024-08-08 22:04 [PATCH][next] smb: smb2pdu.h: Use static_assert() to check struct sizes Gustavo A. R. Silva
@ 2024-08-09 2:51 ` Namjae Jeon
2024-08-09 3:50 ` Steve French
0 siblings, 1 reply; 3+ messages in thread
From: Namjae Jeon @ 2024-08-09 2:51 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Steve French, Sergey Senozhatsky, Tom Talpey, Paulo Alcantara,
Ronnie Sahlberg, Shyam Prasad N, Bharath SM, linux-cifs,
samba-technical, linux-kernel, linux-hardening
2024년 8월 9일 (금) 오전 7:04, Gustavo A. R. Silva <gustavoars@kernel.org>님이 작성:
>
> Commit 9f9bef9bc5c6 ("smb: smb2pdu.h: Avoid -Wflex-array-member-not-at-end
> warnings") introduced tagged `struct create_context_hdr`. We want to
> ensure that when new members need to be added to the flexible structure,
> they are always included within this tagged struct.
>
> So, we use `static_assert()` to ensure that the memory layout for
> both the flexible structure and the tagged struct is the same after
> any changes.
>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Thanks!
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH][next] smb: smb2pdu.h: Use static_assert() to check struct sizes
2024-08-09 2:51 ` Namjae Jeon
@ 2024-08-09 3:50 ` Steve French
0 siblings, 0 replies; 3+ messages in thread
From: Steve French @ 2024-08-09 3:50 UTC (permalink / raw)
To: Namjae Jeon
Cc: Gustavo A. R. Silva, Steve French, Sergey Senozhatsky, Tom Talpey,
Paulo Alcantara, Ronnie Sahlberg, Shyam Prasad N, Bharath SM,
linux-cifs, samba-technical, linux-kernel, linux-hardening
merged into cifs-2.6.git for-next
On Thu, Aug 8, 2024 at 9:51 PM Namjae Jeon <linkinjeon@kernel.org> wrote:
>
> 2024년 8월 9일 (금) 오전 7:04, Gustavo A. R. Silva <gustavoars@kernel.org>님이 작성:
> >
> > Commit 9f9bef9bc5c6 ("smb: smb2pdu.h: Avoid -Wflex-array-member-not-at-end
> > warnings") introduced tagged `struct create_context_hdr`. We want to
> > ensure that when new members need to be added to the flexible structure,
> > they are always included within this tagged struct.
> >
> > So, we use `static_assert()` to ensure that the memory layout for
> > both the flexible structure and the tagged struct is the same after
> > any changes.
> >
> > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> Acked-by: Namjae Jeon <linkinjeon@kernel.org>
>
> Thanks!
>
--
Thanks,
Steve
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-08-08 22:04 [PATCH][next] smb: smb2pdu.h: Use static_assert() to check struct sizes Gustavo A. R. Silva
2024-08-09 2:51 ` Namjae Jeon
2024-08-09 3:50 ` Steve French
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