From 9f28157778ede0d4f183f7ab3b46995bb400abbe Mon Sep 17 00:00:00 2001 From: Minsuk Kang Date: Wed, 14 Dec 2022 10:51:39 +0900 Subject: nfc: pn533: Clear nfc_target before being used 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 Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20221214015139.119673-1-linuxlovemin@yonsei.ac.kr Signed-off-by: Jakub Kicinski --- drivers/nfc/pn533/pn533.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/nfc') 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); -- cgit v1.2.3