net: Fix data-races around sysctl_optmem_max.

While reading sysctl_optmem_max, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Kuniyuki Iwashima 2022-08-23 10:46:49 -07:00 committed by David S. Miller
parent 6bae8ceb90
commit 7de6d09f51
5 changed files with 18 additions and 14 deletions

View File

@ -310,11 +310,12 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk)
static int bpf_sk_storage_charge(struct bpf_local_storage_map *smap,
void *owner, u32 size)
{
int optmem_max = READ_ONCE(sysctl_optmem_max);
struct sock *sk = (struct sock *)owner;
/* same check as in sock_kmalloc() */
if (size <= sysctl_optmem_max &&
atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
if (size <= optmem_max &&
atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
atomic_add(size, &sk->sk_omem_alloc);
return 0;
}

View File

@ -1214,10 +1214,11 @@ void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp)
static bool __sk_filter_charge(struct sock *sk, struct sk_filter *fp)
{
u32 filter_size = bpf_prog_size(fp->prog->len);
int optmem_max = READ_ONCE(sysctl_optmem_max);
/* same check as in sock_kmalloc() */
if (filter_size <= sysctl_optmem_max &&
atomic_read(&sk->sk_omem_alloc) + filter_size < sysctl_optmem_max) {
if (filter_size <= optmem_max &&
atomic_read(&sk->sk_omem_alloc) + filter_size < optmem_max) {
atomic_add(filter_size, &sk->sk_omem_alloc);
return true;
}
@ -1548,7 +1549,7 @@ int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk)
if (IS_ERR(prog))
return PTR_ERR(prog);
if (bpf_prog_size(prog->len) > sysctl_optmem_max)
if (bpf_prog_size(prog->len) > READ_ONCE(sysctl_optmem_max))
err = -ENOMEM;
else
err = reuseport_attach_prog(sk, prog);
@ -1615,7 +1616,7 @@ int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk)
}
} else {
/* BPF_PROG_TYPE_SOCKET_FILTER */
if (bpf_prog_size(prog->len) > sysctl_optmem_max) {
if (bpf_prog_size(prog->len) > READ_ONCE(sysctl_optmem_max)) {
err = -ENOMEM;
goto err_prog_put;
}

View File

@ -2536,7 +2536,7 @@ struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
sysctl_optmem_max)
READ_ONCE(sysctl_optmem_max))
return NULL;
skb = alloc_skb(size, priority);
@ -2554,8 +2554,10 @@ struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
*/
void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
{
if ((unsigned int)size <= sysctl_optmem_max &&
atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
int optmem_max = READ_ONCE(sysctl_optmem_max);
if ((unsigned int)size <= optmem_max &&
atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
void *mem;
/* First do the add, to avoid the race if kmalloc
* might sleep.

View File

@ -772,7 +772,7 @@ static int ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval, int optlen)
if (optlen < GROUP_FILTER_SIZE(0))
return -EINVAL;
if (optlen > sysctl_optmem_max)
if (optlen > READ_ONCE(sysctl_optmem_max))
return -ENOBUFS;
gsf = memdup_sockptr(optval, optlen);
@ -808,7 +808,7 @@ static int compat_ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
if (optlen < size0)
return -EINVAL;
if (optlen > sysctl_optmem_max - 4)
if (optlen > READ_ONCE(sysctl_optmem_max) - 4)
return -ENOBUFS;
p = kmalloc(optlen + 4, GFP_KERNEL);
@ -1233,7 +1233,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, int optname,
if (optlen < IP_MSFILTER_SIZE(0))
goto e_inval;
if (optlen > sysctl_optmem_max) {
if (optlen > READ_ONCE(sysctl_optmem_max)) {
err = -ENOBUFS;
break;
}

View File

@ -210,7 +210,7 @@ static int ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
if (optlen < GROUP_FILTER_SIZE(0))
return -EINVAL;
if (optlen > sysctl_optmem_max)
if (optlen > READ_ONCE(sysctl_optmem_max))
return -ENOBUFS;
gsf = memdup_sockptr(optval, optlen);
@ -244,7 +244,7 @@ static int compat_ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
if (optlen < size0)
return -EINVAL;
if (optlen > sysctl_optmem_max - 4)
if (optlen > READ_ONCE(sysctl_optmem_max) - 4)
return -ENOBUFS;
p = kmalloc(optlen + 4, GFP_KERNEL);