diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-08-23 20:46:49 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-08-24 15:46:57 +0300 |
| commit | 7de6d09f51917c829af2b835aba8bb5040f8e86a (patch) | |
| tree | 89c4f938d7771f6a35cc25e7e2c3db1d6566f293 /net/core/sock.c | |
| parent | 6bae8ceb90ba76cdba39496db936164fa672b9be (diff) | |
| download | linux-7de6d09f51917c829af2b835aba8bb5040f8e86a.tar.xz | |
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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/sock.c')
| -rw-r--r-- | net/core/sock.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index 303af52f3b79..95abf4604d88 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -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. |