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-rw-r--r--kernel/bpf/sockmap.c52
-rw-r--r--net/core/filter.c52
2 files changed, 54 insertions, 50 deletions
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index cf5195c7c331..ce63e5801746 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -236,7 +236,7 @@ static int bpf_tcp_init(struct sock *sk)
}
static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
-static int free_start_sg(struct sock *sk, struct sk_msg_buff *md);
+static int free_start_sg(struct sock *sk, struct sk_msg_buff *md, bool charge);
static void bpf_tcp_release(struct sock *sk)
{
@@ -248,7 +248,7 @@ static void bpf_tcp_release(struct sock *sk)
goto out;
if (psock->cork) {
- free_start_sg(psock->sock, psock->cork);
+ free_start_sg(psock->sock, psock->cork, true);
kfree(psock->cork);
psock->cork = NULL;
}
@@ -330,14 +330,14 @@ static void bpf_tcp_close(struct sock *sk, long timeout)
close_fun = psock->save_close;
if (psock->cork) {
- free_start_sg(psock->sock, psock->cork);
+ free_start_sg(psock->sock, psock->cork, true);
kfree(psock->cork);
psock->cork = NULL;
}
list_for_each_entry_safe(md, mtmp, &psock->ingress, list) {
list_del(&md->list);
- free_start_sg(psock->sock, md);
+ free_start_sg(psock->sock, md, true);
kfree(md);
}
@@ -369,7 +369,7 @@ static void bpf_tcp_close(struct sock *sk, long timeout)
/* If another thread deleted this object skip deletion.
* The refcnt on psock may or may not be zero.
*/
- if (l) {
+ if (l && l == link) {
hlist_del_rcu(&link->hash_node);
smap_release_sock(psock, link->sk);
free_htab_elem(htab, link);
@@ -570,14 +570,16 @@ static void free_bytes_sg(struct sock *sk, int bytes,
md->sg_start = i;
}
-static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md)
+static int free_sg(struct sock *sk, int start,
+ struct sk_msg_buff *md, bool charge)
{
struct scatterlist *sg = md->sg_data;
int i = start, free = 0;
while (sg[i].length) {
free += sg[i].length;
- sk_mem_uncharge(sk, sg[i].length);
+ if (charge)
+ sk_mem_uncharge(sk, sg[i].length);
if (!md->skb)
put_page(sg_page(&sg[i]));
sg[i].length = 0;
@@ -594,9 +596,9 @@ static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md)
return free;
}
-static int free_start_sg(struct sock *sk, struct sk_msg_buff *md)
+static int free_start_sg(struct sock *sk, struct sk_msg_buff *md, bool charge)
{
- int free = free_sg(sk, md->sg_start, md);
+ int free = free_sg(sk, md->sg_start, md, charge);
md->sg_start = md->sg_end;
return free;
@@ -604,7 +606,7 @@ static int free_start_sg(struct sock *sk, struct sk_msg_buff *md)
static int free_curr_sg(struct sock *sk, struct sk_msg_buff *md)
{
- return free_sg(sk, md->sg_curr, md);
+ return free_sg(sk, md->sg_curr, md, true);
}
static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md)
@@ -718,7 +720,7 @@ static int bpf_tcp_ingress(struct sock *sk, int apply_bytes,
list_add_tail(&r->list, &psock->ingress);
sk->sk_data_ready(sk);
} else {
- free_start_sg(sk, r);
+ free_start_sg(sk, r, true);
kfree(r);
}
@@ -752,14 +754,10 @@ static int bpf_tcp_sendmsg_do_redirect(struct sock *sk, int send,
release_sock(sk);
}
smap_release_sock(psock, sk);
- if (unlikely(err))
- goto out;
- return 0;
+ return err;
out_rcu:
rcu_read_unlock();
-out:
- free_bytes_sg(NULL, send, md, false);
- return err;
+ return 0;
}
static inline void bpf_md_init(struct smap_psock *psock)
@@ -822,7 +820,7 @@ more_data:
case __SK_PASS:
err = bpf_tcp_push(sk, send, m, flags, true);
if (unlikely(err)) {
- *copied -= free_start_sg(sk, m);
+ *copied -= free_start_sg(sk, m, true);
break;
}
@@ -845,16 +843,17 @@ more_data:
lock_sock(sk);
if (unlikely(err < 0)) {
- free_start_sg(sk, m);
+ int free = free_start_sg(sk, m, false);
+
psock->sg_size = 0;
if (!cork)
- *copied -= send;
+ *copied -= free;
} else {
psock->sg_size -= send;
}
if (cork) {
- free_start_sg(sk, m);
+ free_start_sg(sk, m, true);
psock->sg_size = 0;
kfree(m);
m = NULL;
@@ -912,6 +911,8 @@ static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
if (unlikely(flags & MSG_ERRQUEUE))
return inet_recv_error(sk, msg, len, addr_len);
+ if (!skb_queue_empty(&sk->sk_receive_queue))
+ return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
rcu_read_lock();
psock = smap_psock_sk(sk);
@@ -922,9 +923,6 @@ static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
goto out;
rcu_read_unlock();
- if (!skb_queue_empty(&sk->sk_receive_queue))
- return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
-
lock_sock(sk);
bytes_ready:
while (copied != len) {
@@ -1122,7 +1120,7 @@ wait_for_memory:
err = sk_stream_wait_memory(sk, &timeo);
if (err) {
if (m && m != psock->cork)
- free_start_sg(sk, m);
+ free_start_sg(sk, m, true);
goto out_err;
}
}
@@ -1581,13 +1579,13 @@ static void smap_gc_work(struct work_struct *w)
bpf_prog_put(psock->bpf_tx_msg);
if (psock->cork) {
- free_start_sg(psock->sock, psock->cork);
+ free_start_sg(psock->sock, psock->cork, true);
kfree(psock->cork);
}
list_for_each_entry_safe(md, mtmp, &psock->ingress, list) {
list_del(&md->list);
- free_start_sg(psock->sock, md);
+ free_start_sg(psock->sock, md, true);
kfree(md);
}
diff --git a/net/core/filter.c b/net/core/filter.c
index c25eb36f1320..2c7801f6737a 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2282,14 +2282,21 @@ static const struct bpf_func_proto bpf_msg_cork_bytes_proto = {
.arg2_type = ARG_ANYTHING,
};
+#define sk_msg_iter_var(var) \
+ do { \
+ var++; \
+ if (var == MAX_SKB_FRAGS) \
+ var = 0; \
+ } while (0)
+
BPF_CALL_4(bpf_msg_pull_data,
struct sk_msg_buff *, msg, u32, start, u32, end, u64, flags)
{
unsigned int len = 0, offset = 0, copy = 0;
+ int bytes = end - start, bytes_sg_total;
struct scatterlist *sg = msg->sg_data;
int first_sg, last_sg, i, shift;
unsigned char *p, *to, *from;
- int bytes = end - start;
struct page *page;
if (unlikely(flags || end <= start))
@@ -2299,21 +2306,22 @@ BPF_CALL_4(bpf_msg_pull_data,
i = msg->sg_start;
do {
len = sg[i].length;
- offset += len;
if (start < offset + len)
break;
- i++;
- if (i == MAX_SKB_FRAGS)
- i = 0;
+ offset += len;
+ sk_msg_iter_var(i);
} while (i != msg->sg_end);
if (unlikely(start >= offset + len))
return -EINVAL;
- if (!msg->sg_copy[i] && bytes <= len)
- goto out;
-
first_sg = i;
+ /* The start may point into the sg element so we need to also
+ * account for the headroom.
+ */
+ bytes_sg_total = start - offset + bytes;
+ if (!msg->sg_copy[i] && bytes_sg_total <= len)
+ goto out;
/* At this point we need to linearize multiple scatterlist
* elements or a single shared page. Either way we need to
@@ -2327,15 +2335,13 @@ BPF_CALL_4(bpf_msg_pull_data,
*/
do {
copy += sg[i].length;
- i++;
- if (i == MAX_SKB_FRAGS)
- i = 0;
- if (bytes < copy)
+ sk_msg_iter_var(i);
+ if (bytes_sg_total <= copy)
break;
} while (i != msg->sg_end);
last_sg = i;
- if (unlikely(copy < end - start))
+ if (unlikely(bytes_sg_total > copy))
return -EINVAL;
page = alloc_pages(__GFP_NOWARN | GFP_ATOMIC, get_order(copy));
@@ -2355,9 +2361,7 @@ BPF_CALL_4(bpf_msg_pull_data,
sg[i].length = 0;
put_page(sg_page(&sg[i]));
- i++;
- if (i == MAX_SKB_FRAGS)
- i = 0;
+ sk_msg_iter_var(i);
} while (i != last_sg);
sg[first_sg].length = copy;
@@ -2367,11 +2371,15 @@ BPF_CALL_4(bpf_msg_pull_data,
* had a single entry though we can just replace it and
* be done. Otherwise walk the ring and shift the entries.
*/
- shift = last_sg - first_sg - 1;
+ WARN_ON_ONCE(last_sg == first_sg);
+ shift = last_sg > first_sg ?
+ last_sg - first_sg - 1 :
+ MAX_SKB_FRAGS - first_sg + last_sg - 1;
if (!shift)
goto out;
- i = first_sg + 1;
+ i = first_sg;
+ sk_msg_iter_var(i);
do {
int move_from;
@@ -2388,15 +2396,13 @@ BPF_CALL_4(bpf_msg_pull_data,
sg[move_from].page_link = 0;
sg[move_from].offset = 0;
- i++;
- if (i == MAX_SKB_FRAGS)
- i = 0;
+ sk_msg_iter_var(i);
} while (1);
msg->sg_end -= shift;
if (msg->sg_end < 0)
msg->sg_end += MAX_SKB_FRAGS;
out:
- msg->data = sg_virt(&sg[i]) + start - offset;
+ msg->data = sg_virt(&sg[first_sg]) + start - offset;
msg->data_end = msg->data + bytes;
return 0;
@@ -7281,7 +7287,7 @@ static u32 sk_reuseport_convert_ctx_access(enum bpf_access_type type,
break;
case offsetof(struct sk_reuseport_md, ip_protocol):
- BUILD_BUG_ON(hweight_long(SK_FL_PROTO_MASK) != BITS_PER_BYTE);
+ BUILD_BUG_ON(HWEIGHT32(SK_FL_PROTO_MASK) != BITS_PER_BYTE);
SK_REUSEPORT_LOAD_SK_FIELD_SIZE_OFF(__sk_flags_offset,
BPF_W, 0);
*insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_PROTO_MASK);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.