* [PATCH net] net: Properly typecast int values to set sk_max_pacing_rate
@ 2020-10-20 0:31 Ke Li
2020-10-22 3:53 ` Jakub Kicinski
0 siblings, 1 reply; 3+ messages in thread
From: Ke Li @ 2020-10-20 0:31 UTC (permalink / raw)
To: netdev; +Cc: davem, kuba, edumazet, kli, Ke Li, Ji Li
In setsockopt(SO_MAX_PACING_RATE) on 64bit systems, sk_max_pacing_rate,
after extended from 'u32' to 'unsigned long', takes unintentionally
hiked value whenever assigned from an 'int' value with MSB=1, due to
binary sign extension in promoting s32 to u64, e.g. 0x80000000 becomes
0xFFFFFFFF80000000.
Thus inflated sk_max_pacing_rate causes subsequent getsockopt to return
~0U unexpectedly. It may also result in increased pacing rate.
Fix by explicitly casting the 'int' value to 'unsigned int' before
assigning it to sk_max_pacing_rate, for zero extension to happen.
Fixes: 76a9ebe811fb ("net: extend sk_pacing_rate to unsigned long")
Signed-off-by: Ji Li <jli@akamai.com>
Signed-off-by: Ke Li <keli@akamai.com>
Cc: Eric Dumazet <edumazet@google.com>
---
net/core/filter.c | 2 +-
net/core/sock.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index c5e2a1c5fd8d..43f20c14864c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4693,7 +4693,7 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname,
cmpxchg(&sk->sk_pacing_status,
SK_PACING_NONE,
SK_PACING_NEEDED);
- sk->sk_max_pacing_rate = (val == ~0U) ? ~0UL : val;
+ sk->sk_max_pacing_rate = (val == ~0U) ? ~0UL : (unsigned int)val;
sk->sk_pacing_rate = min(sk->sk_pacing_rate,
sk->sk_max_pacing_rate);
break;
diff --git a/net/core/sock.c b/net/core/sock.c
index 4e8729357122..727ea1cc633c 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1163,7 +1163,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
case SO_MAX_PACING_RATE:
{
- unsigned long ulval = (val == ~0U) ? ~0UL : val;
+ unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
if (sizeof(ulval) != sizeof(val) &&
optlen >= sizeof(ulval) &&
base-commit: 0e8b8d6a2d85344d80dda5beadd98f5f86e8d3d3
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net] net: Properly typecast int values to set sk_max_pacing_rate
2020-10-20 0:31 [PATCH net] net: Properly typecast int values to set sk_max_pacing_rate Ke Li
@ 2020-10-22 3:53 ` Jakub Kicinski
2020-10-22 6:31 ` Li, Ke
0 siblings, 1 reply; 3+ messages in thread
From: Jakub Kicinski @ 2020-10-22 3:53 UTC (permalink / raw)
To: Ke Li; +Cc: netdev, davem, edumazet, kli, Ji Li
On Mon, 19 Oct 2020 20:31:49 -0400 Ke Li wrote:
> In setsockopt(SO_MAX_PACING_RATE) on 64bit systems, sk_max_pacing_rate,
> after extended from 'u32' to 'unsigned long', takes unintentionally
> hiked value whenever assigned from an 'int' value with MSB=1, due to
> binary sign extension in promoting s32 to u64, e.g. 0x80000000 becomes
> 0xFFFFFFFF80000000.
>
> Thus inflated sk_max_pacing_rate causes subsequent getsockopt to return
> ~0U unexpectedly. It may also result in increased pacing rate.
>
> Fix by explicitly casting the 'int' value to 'unsigned int' before
> assigning it to sk_max_pacing_rate, for zero extension to happen.
>
> Fixes: 76a9ebe811fb ("net: extend sk_pacing_rate to unsigned long")
> Signed-off-by: Ji Li <jli@akamai.com>
> Signed-off-by: Ke Li <keli@akamai.com>
> Cc: Eric Dumazet <edumazet@google.com>
> ---
> net/core/filter.c | 2 +-
> net/core/sock.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/core/filter.c b/net/core/filter.c
> index c5e2a1c5fd8d..43f20c14864c 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -4693,7 +4693,7 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname,
> cmpxchg(&sk->sk_pacing_status,
> SK_PACING_NONE,
> SK_PACING_NEEDED);
> - sk->sk_max_pacing_rate = (val == ~0U) ? ~0UL : val;
> + sk->sk_max_pacing_rate = (val == ~0U) ? ~0UL : (unsigned int)val;
Looks good, but please wrap this to 80 chars.
> sk->sk_pacing_rate = min(sk->sk_pacing_rate,
> sk->sk_max_pacing_rate);
> break;
> diff --git a/net/core/sock.c b/net/core/sock.c
> index 4e8729357122..727ea1cc633c 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -1163,7 +1163,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
>
> case SO_MAX_PACING_RATE:
> {
> - unsigned long ulval = (val == ~0U) ? ~0UL : val;
> + unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
>
> if (sizeof(ulval) != sizeof(val) &&
> optlen >= sizeof(ulval) &&
>
> base-commit: 0e8b8d6a2d85344d80dda5beadd98f5f86e8d3d3
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net] net: Properly typecast int values to set sk_max_pacing_rate
2020-10-22 3:53 ` Jakub Kicinski
@ 2020-10-22 6:31 ` Li, Ke
0 siblings, 0 replies; 3+ messages in thread
From: Li, Ke @ 2020-10-22 6:31 UTC (permalink / raw)
To: Jakub Kicinski; +Cc: netdev, davem, edumazet, kli, Li, Ji
Thanks for review and comment, Jakub!
Please check my v2 patch.
Best,
-Ke
On 10/21/20, 8:53 PM, "Jakub Kicinski" <kuba@kernel.org> wrote:
On Mon, 19 Oct 2020 20:31:49 -0400 Ke Li wrote:
> In setsockopt(SO_MAX_PACING_RATE) on 64bit systems, sk_max_pacing_rate,
> after extended from 'u32' to 'unsigned long', takes unintentionally
> hiked value whenever assigned from an 'int' value with MSB=1, due to
> binary sign extension in promoting s32 to u64, e.g. 0x80000000 becomes
> 0xFFFFFFFF80000000.
>
> Thus inflated sk_max_pacing_rate causes subsequent getsockopt to return
> ~0U unexpectedly. It may also result in increased pacing rate.
>
> Fix by explicitly casting the 'int' value to 'unsigned int' before
> assigning it to sk_max_pacing_rate, for zero extension to happen.
>
> Fixes: 76a9ebe811fb ("net: extend sk_pacing_rate to unsigned long")
> Signed-off-by: Ji Li <jli@akamai.com>
> Signed-off-by: Ke Li <keli@akamai.com>
> Cc: Eric Dumazet <edumazet@google.com>
> ---
> net/core/filter.c | 2 +-
> net/core/sock.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/core/filter.c b/net/core/filter.c
> index c5e2a1c5fd8d..43f20c14864c 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -4693,7 +4693,7 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname,
> cmpxchg(&sk->sk_pacing_status,
> SK_PACING_NONE,
> SK_PACING_NEEDED);
> - sk->sk_max_pacing_rate = (val == ~0U) ? ~0UL : val;
> + sk->sk_max_pacing_rate = (val == ~0U) ? ~0UL : (unsigned int)val;
Looks good, but please wrap this to 80 chars.
> sk->sk_pacing_rate = min(sk->sk_pacing_rate,
> sk->sk_max_pacing_rate);
> break;
> diff --git a/net/core/sock.c b/net/core/sock.c
> index 4e8729357122..727ea1cc633c 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -1163,7 +1163,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
>
> case SO_MAX_PACING_RATE:
> {
> - unsigned long ulval = (val == ~0U) ? ~0UL : val;
> + unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
>
> if (sizeof(ulval) != sizeof(val) &&
> optlen >= sizeof(ulval) &&
>
> base-commit: 0e8b8d6a2d85344d80dda5beadd98f5f86e8d3d3
^ permalink raw reply [flat|nested] 3+ messages in thread
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