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tls: don't use stack memory in a scatterlist
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scatterlist code expects virt_to_page() to work, which fails with
CONFIG_VMAP_STACK=y.

Fixes: c46234e ("tls: RX path for ktls")
Signed-off-by: Matt Mullins <mmullins@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Matt Mullins authored and David S. Miller committed May 17, 2018
1 parent 7063efd commit 8ab6ffb
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Showing 2 changed files with 7 additions and 5 deletions.
3 changes: 3 additions & 0 deletions include/net/tls.h
Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,9 @@ struct tls_sw_context {
u8 control;
bool decrypted;

char rx_aad_ciphertext[TLS_AAD_SPACE_SIZE];
char rx_aad_plaintext[TLS_AAD_SPACE_SIZE];

/* Sending context */
char aad_space[TLS_AAD_SPACE_SIZE];

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9 changes: 4 additions & 5 deletions net/tls/tls_sw.c
Original file line number Diff line number Diff line change
Expand Up @@ -680,7 +680,6 @@ static int decrypt_skb(struct sock *sk, struct sk_buff *skb,
struct scatterlist *sgin = &sgin_arr[0];
struct strp_msg *rxm = strp_msg(skb);
int ret, nsg = ARRAY_SIZE(sgin_arr);
char aad_recv[TLS_AAD_SPACE_SIZE];
struct sk_buff *unused;

ret = skb_copy_bits(skb, rxm->offset + TLS_HEADER_SIZE,
Expand All @@ -698,13 +697,13 @@ static int decrypt_skb(struct sock *sk, struct sk_buff *skb,
}

sg_init_table(sgin, nsg);
sg_set_buf(&sgin[0], aad_recv, sizeof(aad_recv));
sg_set_buf(&sgin[0], ctx->rx_aad_ciphertext, TLS_AAD_SPACE_SIZE);

nsg = skb_to_sgvec(skb, &sgin[1],
rxm->offset + tls_ctx->rx.prepend_size,
rxm->full_len - tls_ctx->rx.prepend_size);

tls_make_aad(aad_recv,
tls_make_aad(ctx->rx_aad_ciphertext,
rxm->full_len - tls_ctx->rx.overhead_size,
tls_ctx->rx.rec_seq,
tls_ctx->rx.rec_seq_size,
Expand Down Expand Up @@ -803,12 +802,12 @@ int tls_sw_recvmsg(struct sock *sk,
if (to_copy <= len && page_count < MAX_SKB_FRAGS &&
likely(!(flags & MSG_PEEK))) {
struct scatterlist sgin[MAX_SKB_FRAGS + 1];
char unused[21];
int pages = 0;

zc = true;
sg_init_table(sgin, MAX_SKB_FRAGS + 1);
sg_set_buf(&sgin[0], unused, 13);
sg_set_buf(&sgin[0], ctx->rx_aad_plaintext,
TLS_AAD_SPACE_SIZE);

err = zerocopy_from_iter(sk, &msg->msg_iter,
to_copy, &pages,
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