[PATCH 5.15 094/123] NFC: nci: Bounds check struct nfc_target arrays

Greg Kroah-Hartman
2022-12-12T13:34:27Z

From: Kees Cook <keescook@chromium.org>

[ Upstream commit e329e71013c9b5a4535b099208493c7826ee4a64 ]

While running under CONFIG_FORTIFY_SOURCE=y, syzkaller reported:

memcpy: detected field-spanning write (size 129) of single field "target->sensf_res" at net/nfc/nci/ntf.c:260 (size 18)

This appears to be a legitimate lack of bounds checking in
nci_add_new_protocol(). Add the missing checks.

Reported-by: syzbot+210e196cef4711b65139@syzkaller.appspotmail.com
Link: https://lore.kernel.org/lkml/0000000000001c590f05ee7b3ff4@google.com
Fixes: 019c4fbaa790 ("NFC: Add NCI multiple targets support")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221202214410.never.693-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/nfc/nci/ntf.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c
index c5eacaac41ae..8f48b1061944 100644
--- a/net/nfc/nci/ntf.c
+++ b/net/nfc/nci/ntf.c
@@ -240,6 +240,8 @@ static int nci_add_new_protocol(struct nci_dev *ndev,
target->sens_res = nfca_poll->sens_res;
target->sel_res = nfca_poll->sel_res;
target->nfcid1_len = nfca_poll->nfcid1_len;
+ if (target->nfcid1_len > ARRAY_SIZE(target->nfcid1))
+ return -EPROTO;
if (target->nfcid1_len > 0) {
memcpy(target->nfcid1, nfca_poll->nfcid1,
target->nfcid1_len);
@@ -248,6 +250,8 @@ static int nci_add_new_protocol(struct nci_dev *ndev,
nfcb_poll = (struct rf_tech_specific_params_nfcb_poll *)params;

target->sensb_res_len = nfcb_poll->sensb_res_len;
+ if (target->sensb_res_len > ARRAY_SIZE(target->sensb_res))
+ return -EPROTO;
if (target->sensb_res_len > 0) {
memcpy(target->sensb_res, nfcb_poll->sensb_res,
target->sensb_res_len);
@@ -256,6 +260,8 @@ static int nci_add_new_protocol(struct nci_dev *ndev,
nfcf_poll = (struct rf_tech_specific_params_nfcf_poll *)params;

target->sensf_res_len = nfcf_poll->sensf_res_len;
+ if (target->sensf_res_len > ARRAY_SIZE(target->sensf_res))
+ return -EPROTO;
if (target->sensf_res_len > 0) {
memcpy(target->sensf_res, nfcf_poll->sensf_res,
target->sensf_res_len);
--
2.35.1