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authorPrashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>2018-03-30 09:21:00 +0900
committerDaniel Borkmann <daniel@iogearbox.net>2018-03-30 22:50:15 +0200
commit6ef6d84ceee2262a8c7a4247616c7eb71268b3f9 (patch)
tree630eb9ec8764b825abe20e0457df291dd0c1f9eb /kernel/bpf
parentf385178679b6561d2e717567d12e07c7f927ee59 (diff)
downloadlinux-6ef6d84ceee2262a8c7a4247616c7eb71268b3f9.tar.bz2
bpf: sockmap: initialize sg table entries properly
When CONFIG_DEBUG_SG is set, sg->sg_magic is initialized in sg_init_table() and it is verified in sg api while navigating. We hit BUG_ON when magic check is failed. In functions sg_tcp_sendpage and sg_tcp_sendmsg, the struct containing the scatterlist is already zeroed out. So to avoid extra memset, we use sg_init_marker() to initialize sg_magic. Fixed following things: - In bpf_tcp_sendpage: initialize sg using sg_init_marker - In bpf_tcp_sendmsg: Replace sg_init_table with sg_init_marker - In bpf_tcp_push: Replace memset with sg_init_table where consumed sg entry needs to be re-initialized. Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/sockmap.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 9192fdbcbccc..d2bda5aa25d7 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -341,7 +341,7 @@ retry:
md->sg_start++;
if (md->sg_start == MAX_SKB_FRAGS)
md->sg_start = 0;
- memset(sg, 0, sizeof(*sg));
+ sg_init_table(sg, 1);
if (md->sg_start == md->sg_end)
break;
@@ -843,7 +843,7 @@ static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
}
sg = md.sg_data;
- sg_init_table(sg, MAX_SKB_FRAGS);
+ sg_init_marker(sg, MAX_SKB_FRAGS);
rcu_read_unlock();
lock_sock(sk);
@@ -950,10 +950,14 @@ static int bpf_tcp_sendpage(struct sock *sk, struct page *page,
lock_sock(sk);
- if (psock->cork_bytes)
+ if (psock->cork_bytes) {
m = psock->cork;
- else
+ sg = &m->sg_data[m->sg_end];
+ } else {
m = &md;
+ sg = m->sg_data;
+ sg_init_marker(sg, MAX_SKB_FRAGS);
+ }
/* Catch case where ring is full and sendpage is stalled. */
if (unlikely(m->sg_end == m->sg_start &&
@@ -961,7 +965,6 @@ static int bpf_tcp_sendpage(struct sock *sk, struct page *page,
goto out_err;
psock->sg_size += size;
- sg = &m->sg_data[m->sg_end];
sg_set_page(sg, page, size, offset);
get_page(page);
m->sg_copy[m->sg_end] = true;