From: Ke Li keli@akamai.com
[ Upstream commit 700465fd338fe5df08a1b2e27fa16981f562547f ]
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 Reviewed-by: Eric Dumazet edumazet@google.com Link: https://lore.kernel.org/r/20201022064146.79873-1-keli@akamai.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/filter.c | 3 ++- net/core/sock.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)
--- a/net/core/filter.c +++ b/net/core/filter.c @@ -4323,7 +4323,8 @@ static int _bpf_setsockopt(struct sock * 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; --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1184,7 +1184,7 @@ set_sndbuf:
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) &&