2020-06-30 14:29:40

by Colin King

Subject: [PATCH][next] net/tls: fix sign extension issue when left shifting u16 value

From: Colin Ian King <[email protected]>

Left shifting the u16 value promotes it to a int and then it
gets sign extended to a u64. If len << 16 is greater than 0x7fffffff
then the upper bits get set to 1 because of the implicit sign extension.
Fix this by casting len to u64 before shifting it.

Addresses-Coverity: ("integer handling issues")
Fixes: ed9b7646b06a ("net/tls: Add asynchronous resync")
Signed-off-by: Colin Ian King <[email protected]>
---
include/net/tls.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/tls.h b/include/net/tls.h
index c875c0a445a6..e5dac7e74e79 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -637,7 +637,7 @@ tls_offload_rx_resync_async_request_start(struct sock *sk, __be32 seq, u16 len)
struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);

atomic64_set(&rx_ctx->resync_async->req, ((u64)ntohl(seq) << 32) |
- (len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC);
+ ((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC);
rx_ctx->resync_async->loglen = 0;
}

--
2.27.0

2020-06-30 14:46:14

by Tariq Toukan

Subject: Re: [PATCH][next] net/tls: fix sign extension issue when left shifting u16 value

On 6/30/2020 5:27 PM, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> Left shifting the u16 value promotes it to a int and then it
> gets sign extended to a u64. If len << 16 is greater than 0x7fffffff
> then the upper bits get set to 1 because of the implicit sign extension.
> Fix this by casting len to u64 before shifting it.
>
> Addresses-Coverity: ("integer handling issues")
> Fixes: ed9b7646b06a ("net/tls: Add asynchronous resync")
> Signed-off-by: Colin Ian King <[email protected]>
> ---
> include/net/tls.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/net/tls.h b/include/net/tls.h
> index c875c0a445a6..e5dac7e74e79 100644
> --- a/include/net/tls.h
> +++ b/include/net/tls.h
> @@ -637,7 +637,7 @@ tls_offload_rx_resync_async_request_start(struct sock *sk, __be32 seq, u16 len)
> struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx);
>
> atomic64_set(&rx_ctx->resync_async->req, ((u64)ntohl(seq) << 32) |
> - (len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC);
> + ((u64)len << 16) | RESYNC_REQ | RESYNC_REQ_ASYNC);
> rx_ctx->resync_async->loglen = 0;
> }
>
>

Reviewed-by: Tariq Toukan <[email protected]>
Thanks!

2020-06-30 21:26:55

by David Miller

Subject: Re: [PATCH][next] net/tls: fix sign extension issue when left shifting u16 value

From: Colin King <[email protected]>
Date: Tue, 30 Jun 2020 15:27:46 +0100

> From: Colin Ian King <[email protected]>
>
> Left shifting the u16 value promotes it to a int and then it
> gets sign extended to a u64. If len << 16 is greater than 0x7fffffff
> then the upper bits get set to 1 because of the implicit sign extension.
> Fix this by casting len to u64 before shifting it.
>
> Addresses-Coverity: ("integer handling issues")
> Fixes: ed9b7646b06a ("net/tls: Add asynchronous resync")
> Signed-off-by: Colin Ian King <[email protected]>

Applied, thanks Colin.