CVE-2026-74666
packet: synchronize pressure clearing with ring reconfiguration
Description
In the Linux kernel, the following vulnerability has been resolved: packet: synchronize pressure clearing with ring reconfiguration packet_set_ring() updates the RX ring state under sk_receive_queue.lock, but used to publish the tpacket receive mode through po->prot_hook.func after releasing that lock. packet_poll() and packet_recvmsg() can then run the pressure clearing path after the ring has been cleared while still seeing tpacket_rcv, causing __packet_rcv_has_room() to dereference stale or NULL ring storage. Move the existing receive hook assignment into the same sk_receive_queue.lock section as the ring state update. Keep the assignment otherwise unchanged, including on TX ring reconfiguration, to avoid adding behavior changes that are not required for the fix. Serialize packet_recvmsg() pressure clearing with the same queue lock only after PACKET_SOCK_PRESSURE has been observed. If the flag is clear and the socket has moved away from tpacket_rcv, packet_set_ring() has already detached the socket and waited for synchronize_net(), so no new packet input can set the flag again. packet_poll() already holds sk_receive_queue.lock, so it uses the new unlocked helper directly.
INFO
Published Date :
Aug. 22, 2026, 4:16 p.m.
Last Modified :
Aug. 22, 2026, 4:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-74666
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel to the latest stable version.
- Apply patches that synchronize ring reconfiguration with pressure clearing.
- Ensure packet_set_ring() updates the RX ring state under lock.
- Serialize packet_recvmsg() pressure clearing with the queue lock.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-74666.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74666 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-74666
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-74666 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74666 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 22, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '2ccdbaa6d55b0656244ba57c4b56765a0af76c0a', 'lessThan': 'cf8189b82bb93f219ab740e0346c919ad65ada62', 'versionType': 'git'}, {'status': 'affected', 'version': '2ccdbaa6d55b0656244ba57c4b56765a0af76c0a', 'lessThan': 'ad740b4990347521f0db260d381f9f74e7b340ba', 'versionType': 'git'}, {'status': 'affected', 'version': '2ccdbaa6d55b0656244ba57c4b56765a0af76c0a', 'lessThan': '2c7b5eb87b2b288cdbde825f21d2b83b2f5da747', 'versionType': 'git'}, {'status': 'affected', 'version': '2ccdbaa6d55b0656244ba57c4b56765a0af76c0a', 'lessThan': 'a08196c3cc105947746ec21309edfbb60275fcdb', 'versionType': 'git'}, {'status': 'affected', 'version': '2ccdbaa6d55b0656244ba57c4b56765a0af76c0a', 'lessThan': '1a35da325cac4d5bcad76a2aa943408a6f1d9000', 'versionType': 'git'}], 'programFiles': ['net/packet/af_packet.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.2'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.2', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.152', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.104', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.45', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.9', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/packet/af_packet.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: packet: synchronize pressure clearing with ring reconfiguration packet_set_ring() updates the RX ring state under sk_receive_queue.lock, but used to publish the tpacket receive mode through po->prot_hook.func after releasing that lock. packet_poll() and packet_recvmsg() can then run the pressure clearing path after the ring has been cleared while still seeing tpacket_rcv, causing __packet_rcv_has_room() to dereference stale or NULL ring storage. Move the existing receive hook assignment into the same sk_receive_queue.lock section as the ring state update. Keep the assignment otherwise unchanged, including on TX ring reconfiguration, to avoid adding behavior changes that are not required for the fix. Serialize packet_recvmsg() pressure clearing with the same queue lock only after PACKET_SOCK_PRESSURE has been observed. If the flag is clear and the socket has moved away from tpacket_rcv, packet_set_ring() has already detached the socket and waited for synchronize_net(), so no new packet input can set the flag again. packet_poll() already holds sk_receive_queue.lock, so it uses the new unlocked helper directly. Added Reference https://git.kernel.org/stable/c/1a35da325cac4d5bcad76a2aa943408a6f1d9000 Added Reference https://git.kernel.org/stable/c/2c7b5eb87b2b288cdbde825f21d2b83b2f5da747 Added Reference https://git.kernel.org/stable/c/a08196c3cc105947746ec21309edfbb60275fcdb Added Reference https://git.kernel.org/stable/c/ad740b4990347521f0db260d381f9f74e7b340ba Added Reference https://git.kernel.org/stable/c/cf8189b82bb93f219ab740e0346c919ad65ada62