CVE - CVE-2022-49889

CVE-ID
CVE-2022-49889	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Check for NULL cpu_buffer in ring_buffer_wake_waiters() On some machines the number of listed CPUs may be bigger than the actual CPUs that exist. The tracing subsystem allocates a per_cpu directory with access to the per CPU ring buffer via a cpuX file. But to save space, the ring buffer will only allocate buffers for online CPUs, even though the CPU array will be as big as the nr_cpu_ids. With the addition of waking waiters on the ring buffer when closing the file, the ring_buffer_wake_waiters() now needs to make sure that the buffer is allocated (with the irq_work allocated with it) before trying to wake waiters, as it will cause a NULL pointer dereference. While debugging this, I added a NULL check for the buffer itself (which is OK to do), and also NULL pointer checks against buffer->buffers (which is not fine, and will WARN) as well as making sure the CPU number passed in is within the nr_cpu_ids (which is also not fine if it isn't). Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=1204705
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/49ca992f6e50d0f46ec9608f44e011cf3121f389 URL:https://git.kernel.org/stable/c/49ca992f6e50d0f46ec9608f44e011cf3121f389 MISC:https://git.kernel.org/stable/c/7433632c9ff68a991bd0bc38cabf354e9d2de410 URL:https://git.kernel.org/stable/c/7433632c9ff68a991bd0bc38cabf354e9d2de410 MISC:https://git.kernel.org/stable/c/b5074df412bf3df9d6ce096b6fa03eb1082d05c9 URL:https://git.kernel.org/stable/c/b5074df412bf3df9d6ce096b6fa03eb1082d05c9
Assigning CNA
kernel.org
Date Record Created
20250501	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20250501)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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