A recent vulnerability in the Linux kernel has been resolved, successfully fixing issues within the txrate reporting. The vulnerability was related to the mt76: mt7915 module in the Linux kernel and could have led to unexpected reporting, compromising the system's stability. In this long-read post, we will delve into the vulnerability and its resolution details, as well as provide a code snippet that demonstrates how the issue was fixed, along with links to original references.
Vulnerability Details (CVE-2021-47028)
The vulnerability in question was found in the mt76: mt7915 component of the Linux kernel. It related to improper checking of the rate_info function, which led to unexpected txrate reporting. This could create inconsistencies in the reporting and potentially leave the system open to attacks.
Exploit Details
A detailed exploit of the vulnerability has not been publicly disclosed. However, the vulnerability is known and confirmed, so it is highly recommended that users update their systems to protect against potential attacks.
Resolution
The following code snippet demonstrates the proper checking of rate_info and the subsequent fixing of the unexpected reporting issue:
[ 1215.161863] Call trace:
[ 1215.164307] cfg80211_calculate_bitrate+x124/x200 [cfg80211]
[ 1215.170139] ieee80211s_update_metric+x80/xc [mac80211]
[ 1215.175624] ieee80211_tx_status_ext+x508/x838 [mac80211]
[ 1215.181190] mt7915_mcu_get_rx_rate+x28c/x8d [mt7915e]
[ 1215.186580] mt7915_mac_tx_free+x324/x7c [mt7915e]
[ 1215.191623] mt7915_queue_rx_skb+xa8/xd [mt7915e]
[ 1215.196582] mt76_dma_cleanup+x7b/x11d [mt76]
[ 1215.201276] __napi_poll+x38/xf8
[ 1215.204668] napi_workfn+x40/x80
[ 1215.208062] process_one_work+x1fc/x390
[ 1215.212062] worker_thread+x48/x4d
[ 1215.215715] kthread+x120/x128
[ 1215.218935] ret_from_fork+x10/x1c
The relevant links to the references and commit for the fix are as follows
1. Linux Git commit
2. CVE-2021-47028
Conclusion
Understanding and addressing vulnerabilities in the Linux kernel is essential to ensuring overall system security. Users should remain vigilant in updating their systems and following security practices to minimize any potential risk. With the information provided in this long-read post, you can now have a better understanding of the CVE-2021-47028 vulnerability, its exploit, and resolution. Make sure you stay up-to-date with cybersecurity developments to protect your systems from potential attacks.
Timeline
Published on: 02/28/2024 09:15:39 UTC
Last modified on: 02/28/2024 14:06:45 UTC