Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: scs: fix a wrong parameter in __scs_magic __scs_magic() needs a 'void *' variable, but a 'struct task_struct *' is given. 'task_scs(tsk)' is the starting address of the task's shadow call stack, and '__scs_magic(task_scs(tsk))' is the end address of the task's shadow call stack. Here should be '__scs_magic(task_scs(tsk))'. The user-visible effect of this bug is that when CONFIG_DEBUG_STACK_USAGE is enabled, the shadow call stack usage checking function (scs_check_usage) would scan an incorrect memory range. This could lead 1. **Inaccurate stack usage reporting**: The function would calculate wrong usage statistics for the shadow call stack, potentially showing incorrect value in kmsg. 2. **Potential kernel crash**: If the value of __scs_magic(tsk)is greater than that of __scs_magic(task_scs(tsk)), the for loop may access unmapped memory, potentially causing a kernel panic. However, this scenario is unlikely because task_struct is allocated via the slab allocator (which typically returns lower addresses), while the shadow call stack returned by task_scs(tsk) is allocated via vmalloc(which typically returns higher addresses). However, since this is purely a debugging feature (CONFIG_DEBUG_STACK_USAGE), normal production systems should be not unaffected. The bug only impacts developers and testers who are actively debugging stack usage with this configuration enabled.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 5bbaf9d1fcb9be696ee9a61636ab6803556c70f2 before 1727e8bd69103a68963a5613a0ddb6d8d37df5d3; affected 5bbaf9d1fcb9be696ee9a61636ab6803556c70f2 before cfdf6250b63b953b1d8e60814c8ca96c6f9d1c8c; affected 5bbaf9d1fcb9be696ee9a61636ab6803556c70f2 before 57ba40b001be27786d0570dd292289df748b306b; affected 5bbaf9d1fcb9be696ee9a61636ab6803556c70f2 before 062774439d442882b44f5eab8c256ad3423ef284; affected 5bbaf9d1fcb9be696ee9a61636ab6803556c70f2 before 9ef28943471a16e4f9646bc3e8e2de148e7d8d7b; affected 5bbaf9d1fcb9be696ee9a61636ab6803556c70f2 before a19fb3611e4c06624fc0f83ef19f4fb8d57d4751; affected 5bbaf9d1fcb9be696ee9a61636ab6803556c70f2 before 08bd4c46d5e63b78e77f2605283874bbe868ab19 |
| Linux / Linux | affected 5.8; unaffected 0 before 5.8; unaffected 5.10.248 through 5.10.*; unaffected 5.15.198 through 5.15.*; unaffected 6.1.160 through 6.1.*; unaffected 6.6.120 through 6.6.*; unaffected 6.12.64 through 6.12.*; unaffected 6.18.3 through 6.18.*; unaffected 6.19 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/1727e8bd69103a68963a5613a0ddb6d8d37df5d3
- https://git.kernel.org/stable/c/cfdf6250b63b953b1d8e60814c8ca96c6f9d1c8c
- https://git.kernel.org/stable/c/57ba40b001be27786d0570dd292289df748b306b
- https://git.kernel.org/stable/c/062774439d442882b44f5eab8c256ad3423ef284
- https://git.kernel.org/stable/c/9ef28943471a16e4f9646bc3e8e2de148e7d8d7b
- https://git.kernel.org/stable/c/a19fb3611e4c06624fc0f83ef19f4fb8d57d4751
- https://git.kernel.org/stable/c/08bd4c46d5e63b78e77f2605283874bbe868ab19