Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: ftrace: Take trace_array reference before accessing its ftrace_ops The trace instance files set_ftrace_filter and set_ftrace_notrace was updated to work with specific trace instances (trace_arrays). The issue is that when these files are opened, there is a small race window where it will use the ftrace_ops from the inode->private pointer to get a reference to the trace_array and then take its reference. The problem is that the ftrace_ops itself could be freed. If the rmdir on the instance happens at the same time the set_ftrace_filter file is opened, the rmdir could have also freed the ftrace_ops and referencing it will cause a use-after-free bug and crash the kernel. Instead, pass in the trace_array as the file private data (NULL for the top level instance), and then pass both the trace_array and the ftrace_ops to the ftrace_regex_open() function. If the trace_array is NULL, then it just uses the ftrace_ops without the need to take its reference (like normal). If the ftrace_ops is NULL, that is only the case for the top level instance and the global_ops can be used. This allows the trace_array to have its reference incremented before touching the ftrace_ops that could also be freed when the instance is.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 591dffdade9f07692a7dd3ed16830ec24e901ece before 29266da8ee1d9be656b1f22460c49538e1930658; affected 591dffdade9f07692a7dd3ed16830ec24e901ece before 177cd8966325f0ffffa3c9381f9e0422019a3973; affected 591dffdade9f07692a7dd3ed16830ec24e901ece before 83fd7eca5ab0d3ac3f23bff889175d847e21af06; affected 591dffdade9f07692a7dd3ed16830ec24e901ece before cee8f286794df916553d8d445eac5c323ec5b0f8; affected 591dffdade9f07692a7dd3ed16830ec24e901ece before 9100191e5acb2e5ea2313f436667bb5fce129f47 |
| Linux / Linux | affected 3.15; unaffected 0 before 3.15; unaffected 6.6.160 through 6.6.*; unaffected 6.12.112 through 6.12.*; unaffected 6.18.52 through 6.18.*; unaffected 7.2.5 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/29266da8ee1d9be656b1f22460c49538e1930658
- https://git.kernel.org/stable/c/177cd8966325f0ffffa3c9381f9e0422019a3973
- https://git.kernel.org/stable/c/83fd7eca5ab0d3ac3f23bff889175d847e21af06
- https://git.kernel.org/stable/c/cee8f286794df916553d8d445eac5c323ec5b0f8
- https://git.kernel.org/stable/c/9100191e5acb2e5ea2313f436667bb5fce129f47