Re: [PATCH net-next v25 10/13] net: add SO_DEVMEM_DONTNEED setsockopt to release RX frags
From: Jakub Kicinski <kuba@kernel.org>
Date: 2024-10-11 15:27:11
Also in:
bpf, dri-devel, linux-alpha, linux-arch, linux-doc, linux-kselftest, linux-media, linux-mips, lkml, netdev, sparclinux
On Thu, 10 Oct 2024 12:05:38 -0700 Mina Almasry wrote:
quoted hunk ↗ jump to hunk
diff --git a/net/core/sock.c b/net/core/sock.c index 083d438d8b6f..cb3d8b19de14 100644 --- a/net/core/sock.c +++ b/net/core/sock.c@@ -1071,11 +1071,11 @@ sock_devmem_dontneed(struct sock *sk,sockptr_t optval, unsigned int optlen) optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS) return -EINVAL; - tokens = kvmalloc_array(optlen, sizeof(*tokens), GFP_KERNEL); + num_tokens = optlen / sizeof(struct dmabuf_token); + tokens = kvmalloc_array(num_tokens, sizeof(*tokens), GFP_KERNEL); if (!tokens) return -ENOMEM; - num_tokens = optlen / sizeof(struct dmabuf_token); if (copy_from_sockptr(tokens, optval, optlen)) { kvfree(tokens); return -EFAULT;@@ -1083,6 +1083,10 @@ sock_devmem_dontneed(struct sock *sk, sockptr_toptval, unsigned int optlen) xa_lock_bh(&sk->sk_user_frags); for (i = 0; i < num_tokens; i++) { + + if (tokens[i].token_count > MAX_DONTNEED_TOKENS) + continue;
For the real fix let's scan the tokens before we take the xa lock and return an error rather than silently skipping?
for (j = 0; j < tokens[i].token_count; j++) {