# CVE-2021-47559: linux: In the Linux kernel, the following vulnerability has been resolved:  net/smc: Fix NULL pointer dereferencing in smc_v...

CVE-2021-47559 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47559, released May 24, 2024. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-47559
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0047
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 24, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  net/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk()  Coverity reports a possible NULL dereferencing problem:  in smc_vlan_by_tcpsk(): 6. returned_null: netdev_lower_get_next returns NULL (checked 29 out of 30 times). 7. var_assigned: Assigning: ndev = NULL return value from netdev_lower_get_next. 1623                ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower); CID 1468509 (#1 of 1): Dereference null return value (NULL_RETURNS) 8. dereference: Dereferencing a pointer that might be NULL ndev when calling is_vlan_dev. 1624                if (is_vlan_dev(ndev)) {  Remove the manual implementation and use netdev_walk_all_lower_dev() to iterate over the lower devices. While on it remove an obsolete function parameter comment.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.15.15-1 | [DEBIAN-CVE-2021-47559](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47559.md) | May 24, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.15.15-1 | [DEBIAN-CVE-2021-47559](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47559.md) | May 24, 2024 |
| Linux | linux Debian 14 | 5.15.15-1 | [DEBIAN-CVE-2021-47559](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47559.md) | May 24, 2024 |

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