[net v2] tcp: Explicitly mark reserved field in tcp_zerocopy_receive args.

From: Arjun Roy <redacted>

Explicitly define reserved field and require it to be 0-valued.

Fixes: 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.")
Signed-off-by: Arjun Roy <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <redacted>
Suggested-by: David Ahern <redacted>
Suggested-by: Leon Romanovsky <leon@kernel.org>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
---
 include/uapi/linux/tcp.h | 2 +-
 net/ipv4/tcp.c           | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 42fc5a640df4..8fc09e8638b3 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h

@@ -357,6 +357,6 @@ struct tcp_zerocopy_receive {
 	__u64 msg_control; /* ancillary data */
 	__u64 msg_controllen;
 	__u32 msg_flags;
-	/* __u32 hole;  Next we must add >1 u32 otherwise length checks fail. */
+	__u32 reserved; /* set to 0 for now */
 };
 #endif /* _UAPI_LINUX_TCP_H */

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index e1a17c6b473c..c8469c579ed8 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c

@@ -4159,6 +4159,8 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
 		}
 		if (copy_from_user(&zc, optval, len))
 			return -EFAULT;
+		if (zc.reserved)
+			return -EINVAL;
 		lock_sock(sk);
 		err = tcp_zerocopy_receive(sk, &zc, &tss);
 		release_sock(sk);

-- 
2.30.0.478.g8a0d178c01-goog

On 2/6/21 12:02 AM, Arjun Roy wrote:

From: Arjun Roy <redacted>

Explicitly define reserved field and require it to be 0-valued.

Fixes: 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.")
Signed-off-by: Arjun Roy <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <redacted>
Suggested-by: David Ahern <redacted>
Suggested-by: Leon Romanovsky <leon@kernel.org>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
---
 include/uapi/linux/tcp.h | 2 +-
 net/ipv4/tcp.c           | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

Reviewed-by: David Ahern <redacted>

On Fri,  5 Feb 2021 23:02:03 -0800 Arjun Roy wrote:

From: Arjun Roy <redacted>

Explicitly define reserved field and require it to be 0-valued.

Fixes: 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.")
Signed-off-by: Arjun Roy <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <redacted>
Suggested-by: David Ahern <redacted>
Suggested-by: Leon Romanovsky <leon@kernel.org>
Suggested-by: Jakub Kicinski <kuba@kernel.org>

Applying: tcp: Explicitly mark reserved field in tcp_zerocopy_receive args.
Using index info to reconstruct a base tree...
M	include/uapi/linux/tcp.h
M	net/ipv4/tcp.c
Falling back to patching base and 3-way merge...
Auto-merging net/ipv4/tcp.c
Auto-merging include/uapi/linux/tcp.h
CONFLICT (content): Merge conflict in include/uapi/linux/tcp.h
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 tcp: Explicitly mark reserved field in tcp_zerocopy_receive args.
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

On Sat, 6 Feb 2021 09:19:03 -0800 Jakub Kicinski wrote:

On Fri,  5 Feb 2021 23:02:03 -0800 Arjun Roy wrote:

quoted

From: Arjun Roy <redacted>

Explicitly define reserved field and require it to be 0-valued.

Fixes: 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.")
Signed-off-by: Arjun Roy <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <redacted>
Suggested-by: David Ahern <redacted>
Suggested-by: Leon Romanovsky <leon@kernel.org>
Suggested-by: Jakub Kicinski <kuba@kernel.org>  

Applying: tcp: Explicitly mark reserved field in tcp_zerocopy_receive args.
Using index info to reconstruct a base tree...
M	include/uapi/linux/tcp.h
M	net/ipv4/tcp.c
Falling back to patching base and 3-way merge...
Auto-merging net/ipv4/tcp.c
Auto-merging include/uapi/linux/tcp.h
CONFLICT (content): Merge conflict in include/uapi/linux/tcp.h
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 tcp: Explicitly mark reserved field in tcp_zerocopy_receive args.
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

Ah, you just marked it for the wrong tree. Please repost with net-next
in the subject tag, otherwise build bot won't handle it.

On Sat, Feb 6, 2021 at 9:20 AM Jakub Kicinski [off-list ref] wrote:

On Sat, 6 Feb 2021 09:19:03 -0800 Jakub Kicinski wrote:

quoted

On Fri,  5 Feb 2021 23:02:03 -0800 Arjun Roy wrote:

quoted

From: Arjun Roy <redacted>

Explicitly define reserved field and require it to be 0-valued.

Fixes: 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.")
Signed-off-by: Arjun Roy <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <redacted>
Suggested-by: David Ahern <redacted>
Suggested-by: Leon Romanovsky <leon@kernel.org>
Suggested-by: Jakub Kicinski <kuba@kernel.org>

Applying: tcp: Explicitly mark reserved field in tcp_zerocopy_receive args.
Using index info to reconstruct a base tree...
M     include/uapi/linux/tcp.h
M     net/ipv4/tcp.c
Falling back to patching base and 3-way merge...
Auto-merging net/ipv4/tcp.c
Auto-merging include/uapi/linux/tcp.h
CONFLICT (content): Merge conflict in include/uapi/linux/tcp.h
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 tcp: Explicitly mark reserved field in tcp_zerocopy_receive args.
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

Ah, you just marked it for the wrong tree. Please repost with net-next
in the subject tag, otherwise build bot won't handle it.

Resent with net-next.

Thanks,
-Arjun