[PATCH 6.0 0849/1073] nfc: pn533: Clear nfc_target before being used

Greg Kroah-Hartman
2022-12-28T16:33:17Z

From: Minsuk Kang <linuxlovemin@yonsei.ac.kr>

[ Upstream commit 9f28157778ede0d4f183f7ab3b46995bb400abbe ]

Fix a slab-out-of-bounds read that occurs in nla_put() called from
nfc_genl_send_target() when target->sensb_res_len, which is duplicated
from an nfc_target in pn533, is too large as the nfc_target is not
properly initialized and retains garbage values. Clear nfc_targets with
memset() before they are used.

Found by a modified version of syzkaller.

BUG: KASAN: slab-out-of-bounds in nla_put
Call Trace:
memcpy
nla_put
nfc_genl_dump_targets
genl_lock_dumpit
netlink_dump
__netlink_dump_start
genl_family_rcv_msg_dumpit
genl_rcv_msg
netlink_rcv_skb
genl_rcv
netlink_unicast
netlink_sendmsg
sock_sendmsg
____sys_sendmsg
___sys_sendmsg
__sys_sendmsg
do_syscall_64

Fixes: 673088fb42d0 ("NFC: pn533: Send ATR_REQ directly for active device detection")
Fixes: 361f3cb7f9cf ("NFC: DEP link hook implementation for pn533")
Signed-off-by: Minsuk Kang <linuxlovemin@yonsei.ac.kr>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221214015139.119673-1-linuxlovemin@yonsei.ac.kr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nfc/pn533/pn533.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index d9f6367b9993..f0cac1900552 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -1295,6 +1295,8 @@ static int pn533_poll_dep_complete(struct pn533 *dev, void *arg,
if (IS_ERR(resp))
return PTR_ERR(resp);

+ memset(&nfc_target, 0, sizeof(struct nfc_target));
+
rsp = (struct pn533_cmd_jump_dep_response *)resp->data;

rc = rsp->status & PN533_CMD_RET_MASK;
@@ -1926,6 +1928,8 @@ static int pn533_in_dep_link_up_complete(struct pn533 *dev, void *arg,

dev_dbg(dev->dev, "Creating new target\n");

+ memset(&nfc_target, 0, sizeof(struct nfc_target));
+
nfc_target.supported_protocols = NFC_PROTO_NFC_DEP_MASK;
nfc_target.nfcid1_len = 10;
memcpy(nfc_target.nfcid1, rsp->nfcid3t, nfc_target.nfcid1_len);
--
2.35.1