| Message ID | 20210712195546.423990-2-john.fastabend@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 7e6b27a69167f97c56b5437871d29e9722c3e470 |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf, sockmap: fix potential memory leak | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 8 maintainers not CCed: yhs@fb.com kpsingh@kernel.org andrii@kernel.org kafai@fb.com lmb@cloudflare.com songliubraving@fb.com davem@davemloft.net kuba@kernel.org |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 1 this patch: 1 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 46 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 1 this patch: 1 |
| netdev/header_inline | success | Link |
On Mon, Jul 12, 2021 at 12:56 PM John Fastabend <john.fastabend@gmail.com> wrote: > > If skb_linearize is needed and fails we could leak a msg on the error > handling. To fix ensure we kfree the msg block before returning error. > Found during code review. > > Fixes: 4363023d2668e ("bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list") > Signed-off-by: John Fastabend <john.fastabend@gmail.com> Reviewed-by: Cong Wang <cong.wang@bytedance.com> Thanks for the update.
diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 9b6160a191f8..15d71288e741 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -508,10 +508,8 @@ static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb, if (skb_linearize(skb)) return -EAGAIN; num_sge = skb_to_sgvec(skb, msg->sg.data, 0, skb->len); - if (unlikely(num_sge < 0)) { - kfree(msg); + if (unlikely(num_sge < 0)) return num_sge; - } copied = skb->len; msg->sg.start = 0; @@ -530,6 +528,7 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb) { struct sock *sk = psock->sk; struct sk_msg *msg; + int err; /* If we are receiving on the same sock skb->sk is already assigned, * skip memory accounting and owner transition seeing it already set @@ -548,7 +547,10 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb) * into user buffers. */ skb_set_owner_r(skb, sk); - return sk_psock_skb_ingress_enqueue(skb, psock, sk, msg); + err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg); + if (err < 0) + kfree(msg); + return err; } /* Puts an skb on the ingress queue of the socket already assigned to the @@ -559,12 +561,16 @@ static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb { struct sk_msg *msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC); struct sock *sk = psock->sk; + int err; if (unlikely(!msg)) return -EAGAIN; sk_msg_init(msg); skb_set_owner_r(skb, sk); - return sk_psock_skb_ingress_enqueue(skb, psock, sk, msg); + err = sk_psock_skb_ingress_enqueue(skb, psock, sk, msg); + if (err < 0) + kfree(msg); + return err; } static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb,
If skb_linearize is needed and fails we could leak a msg on the error handling. To fix ensure we kfree the msg block before returning error. Found during code review. Fixes: 4363023d2668e ("bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list") Signed-off-by: John Fastabend <john.fastabend@gmail.com> --- net/core/skmsg.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)