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| author | Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp> | 2018-03-30 09:21:00 +0900 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-03-30 22:50:15 +0200 |
| commit | 6ef6d84ceee2262a8c7a4247616c7eb71268b3f9 (patch) | |
| tree | 630eb9ec8764b825abe20e0457df291dd0c1f9eb /kernel/bpf | |
| parent | f385178679b6561d2e717567d12e07c7f927ee59 (diff) | |
| download | linux-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.c | 13 |
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; |