Commit 73e2648c authored by Aleksandr Mishin's avatar Aleksandr Mishin Committed by Lin Ruifeng
Browse files

nfc: pn533: Add poll mod list filling check 

stable inclusion
from stable-v6.6.49
commit 56ad559cf6d87f250a8d203b555dfc3716afa946
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAR4F8
CVE: CVE-2024-46676

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=

...

--------------------------------

[ Upstream commit febccb39255f9df35527b88c953b2e0deae50e53 ]

In case of im_protocols value is 1 and tm_protocols value is 0 this
combination successfully passes the check
'if (!im_protocols && !tm_protocols)' in the nfc_start_poll().
But then after pn533_poll_create_mod_list() call in pn533_start_poll()
poll mod list will remain empty and dev->poll_mod_count will remain 0
which lead to division by zero.

Normally no im protocol has value 1 in the mask, so this combination is
not expected by driver. But these protocol values actually come from
userspace via Netlink interface (NFC_CMD_START_POLL operation). So a
broken or malicious program may pass a message containing a "bad"
combination of protocol parameter values so that dev->poll_mod_count
is not incremented inside pn533_poll_create_mod_list(), thus leading
to division by zero.
Call trace looks like:
nfc_genl_start_poll()
  nfc_start_poll()
    ->start_poll()
    pn533_start_poll()

Add poll mod list filling check.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: dfccd0f5 ("NFC: pn533: Add some polling entropy")
Signed-off-by: default avatarAleksandr Mishin <amishin@t-argos.ru>
Acked-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20240827084822.18785-1-amishin@t-argos.ru


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarLin Ruifeng <linruifeng4@huawei.com>
parent b5213571

drivers/nfc/pn533/pn533.c

+5 −0
Original line number Diff line number Diff line
@@ -1723,6 +1723,11 @@ static int pn533_start_poll(struct nfc_dev *nfc_dev, 
	}



	pn533_poll_create_mod_list(dev, im_protocols, tm_protocols);

	if (!dev->poll_mod_count) {

		nfc_err(dev->dev,

			"Poll mod list is empty\n");

		return -EINVAL;

	}



	/* Do not always start polling from the same modulation */

	get_random_bytes(&rand_mod, sizeof(rand_mod));