Description

In the Linux kernel, the following vulnerability has been resolved:

nfc: pn533: Add poll mod list filling check

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.

Classification

CVE ID: CVE-2024-46676

CVSS Base Severity: MEDIUM

CVSS Base Score: 5.5

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 16.81% (scored less or equal to compared to others)

EPSS Date: 2025-06-02 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: false

References

https://nvd.nist.gov/vuln/detail/CVE-2024-46676
https://git.kernel.org/stable/c/c5e05237444f32f6cfe5d907603a232c77a08b31
https://git.kernel.org/stable/c/8ddaea033de051ed61b39f6b69ad54a411172b33
https://git.kernel.org/stable/c/7535db0624a2dede374c42040808ad9a9101d723
https://git.kernel.org/stable/c/7ecd3dd4f8eecd3309432156ccfe24768e009ec4
https://git.kernel.org/stable/c/56ad559cf6d87f250a8d203b555dfc3716afa946
https://git.kernel.org/stable/c/64513d0e546a1f19e390f7e5eba3872bfcbdacf5
https://git.kernel.org/stable/c/febccb39255f9df35527b88c953b2e0deae50e53

Timeline