diff options
| author | Kees Cook | 2022-09-23 21:08:35 -0700 |
|---|---|---|
| committer | Jakub Kicinski | 2022-09-27 07:45:18 -0700 |
| commit | de4feb4e3d61026f81b15ada6f64deaf40125ffc (patch) | |
| tree | 592cc0d923b1c86654465d4b0bcf8ee0e6ca92fe | |
| parent | 454b20e19322e6a9375cbaad68fff3c93bd27716 (diff) | |
NFC: hci: Split memcpy() of struct hcp_message flexible array
To work around a misbehavior of the compiler's ability to see into
composite flexible array structs (as detailed in the coming memcpy()
hardening series[1]), split the memcpy() of the header and the payload
so no false positive run-time overflow warning will be generated. This
split already existed for the "firstfrag" case, so just generalize the
logic further.
[1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@chromium.org/
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Reported-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220924040835.3364912-1-keescook@chromium.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/nfc/hci/hcp.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/net/nfc/hci/hcp.c b/net/nfc/hci/hcp.c index 05c60988f59a..4902f5064098 100644 --- a/net/nfc/hci/hcp.c +++ b/net/nfc/hci/hcp.c @@ -73,14 +73,12 @@ int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe, if (firstfrag) { firstfrag = false; packet->message.header = HCP_HEADER(type, instruction); - if (ptr) { - memcpy(packet->message.data, ptr, - data_link_len - 1); - ptr += data_link_len - 1; - } } else { - memcpy(&packet->message, ptr, data_link_len); - ptr += data_link_len; + packet->message.header = *ptr++; + } + if (ptr) { + memcpy(packet->message.data, ptr, data_link_len - 1); + ptr += data_link_len - 1; } /* This is the last fragment, set the cb bit */ |