Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: tracing: Take trace_array reference when opening options file The options files do not take the trace_array reference for the options they represent. This could cause a use-after-free kernel crash if one of these files is opened by one task and another task removes the instance that the option is for. Because it doesn't take a reference upon opening, it will not stop the removal which will free the options descriptor that is being used. As the options are somewhat dynamic in their creation at boot up, each file represents a flag in the trace_array. The trace_array has an array of indexes to represent each of these flags that is stored in the trace_flags_index array. The address of the index array element is used to pass to the inode->i_private pointer. Then that element is read which holds the index (which represents the flag) and then the index is used to calculate the trace_array descriptor from its trace_flags_index array. One issue is that the index element can not be referenced until the trace_array's reference is taken. To handle this, create a new helper function called: trace_array_options_get() that will iterate all the existing trace_arrays in the ftrace_trace_arrays list (under the trace_types_lock), and compare the passed in address of the index element with the entire array of the trace_array's trace_flags_index array. If it matches, then up the corresponding trace_array's reference and return.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 577b785f55168d5acb3d123ba41bfe8d7981e044 before 8cc9c5a8c559d655c32d2190486e89574c14ff52; affected 577b785f55168d5acb3d123ba41bfe8d7981e044 before 97ceaffbd672449ad7ead5ae8788dce16374b0c1; affected 577b785f55168d5acb3d123ba41bfe8d7981e044 before d0f37d77b9b4b241e0b30ef2562f6353cbda3bec; affected 577b785f55168d5acb3d123ba41bfe8d7981e044 before 64a41f4a9a968f54f3792399aa4d2a9fdb23b0a5; affected 577b785f55168d5acb3d123ba41bfe8d7981e044 before f2951ebd15c36a1ea4820a7f0cbb0b5f1c028b73 |
| Linux / Linux | affected 2.6.30; unaffected 0 before 2.6.30; 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/8cc9c5a8c559d655c32d2190486e89574c14ff52
- https://git.kernel.org/stable/c/97ceaffbd672449ad7ead5ae8788dce16374b0c1
- https://git.kernel.org/stable/c/d0f37d77b9b4b241e0b30ef2562f6353cbda3bec
- https://git.kernel.org/stable/c/64a41f4a9a968f54f3792399aa4d2a9fdb23b0a5
- https://git.kernel.org/stable/c/f2951ebd15c36a1ea4820a7f0cbb0b5f1c028b73