Description
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 products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
577b785f55168d5acb3d123ba41bfe8d7981e044 to < a6e15eadfdb6de30c24ef21b31f39a86359f4ab5affected577b785f55168d5acb3d123ba41bfe8d7981e044 to < 8cc9c5a8c559d655c32d2190486e89574c14ff52affected577b785f55168d5acb3d123ba41bfe8d7981e044 to < 97ceaffbd672449ad7ead5ae8788dce16374b0c1affected577b785f55168d5acb3d123ba41bfe8d7981e044 to < d0f37d77b9b4b241e0b30ef2562f6353cbda3becaffected577b785f55168d5acb3d123ba41bfe8d7981e044 to < 64a41f4a9a968f54f3792399aa4d2a9fdb23b0a5affected577b785f55168d5acb3d123ba41bfe8d7981e044 to < f2951ebd15c36a1ea4820a7f0cbb0b5f1c028b73affected
Linux Linux
Default version status: affected
2.6.30affected0 to < 2.6.30unaffected6.1.191 to ≤ 6.1.*unaffected6.6.160 to ≤ 6.6.*unaffected6.12.112 to ≤ 6.12.*unaffected6.18.52 to ≤ 6.18.*unaffected7.2.5 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/a6e15eadfdb6de30c24ef21b31f39a86359f4ab5 ↗
- 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 ↗