[PATCH 20/23] nfctype5: Discard extra byte in RMB response data
From: Mark Greer <mgreer@animalcreek.com>
Date: 2017-06-15 18:25:28
Subsystem:
the rest · Maintainer:
Linus Torvalds
Sometimes there can be an extra byte in the response data for Read Multiple Blocks (RMB) commands so discard it whenever that happens. Signed-off-by: Mark Greer <mgreer@animalcreek.com> --- plugins/nfctype5.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/plugins/nfctype5.c b/plugins/nfctype5.c
index a91d8f5..d6eec3c 100644
--- a/plugins/nfctype5.c
+++ b/plugins/nfctype5.c@@ -654,7 +654,7 @@ static int t5_read_multiple_blocks_resp(uint8_t *resp, int length, void *data) uint8_t blk_size = near_tag_get_blk_size(tag); size_t data_length; GList *records; - int err; + int err, expected_len; DBG("");
@@ -665,9 +665,16 @@ static int t5_read_multiple_blocks_resp(uint8_t *resp, int length, void *data) goto out_done; length -= NFC_HEADER_SIZE; + expected_len = sizeof(*t5_resp) + + cookie->nb_requested_blocks * blk_size; - if (length != (int)(sizeof(*t5_resp) + - (cookie->nb_requested_blocks * blk_size))) { + /* + * Sometimes an extra byte is returned in RMB response data. + * Discard the extra byte whenever that happens. + */ + if (length == (expected_len + 1)) { + length--; + } else if (length != expected_len) { err = -EIO; goto out_done; }
--
2.13.0