diff options
Diffstat (limited to 'Documentation/security')
| -rw-r--r-- | Documentation/security/LSM.txt | 7 | ||||
| -rw-r--r-- | Documentation/security/self-protection.txt | 10 |
2 files changed, 15 insertions, 2 deletions
diff --git a/Documentation/security/LSM.txt b/Documentation/security/LSM.txt index 3db7e671c440..c2683f28ed36 100644 --- a/Documentation/security/LSM.txt +++ b/Documentation/security/LSM.txt @@ -22,6 +22,13 @@ system, building their checks on top of the defined capability hooks. For more details on capabilities, see capabilities(7) in the Linux man-pages project. +A list of the active security modules can be found by reading +/sys/kernel/security/lsm. This is a comma separated list, and +will always include the capability module. The list reflects the +order in which checks are made. The capability module will always +be first, followed by any "minor" modules (e.g. Yama) and then +the one "major" module (e.g. SELinux) if there is one configured. + Based on https://lkml.org/lkml/2007/10/26/215, a new LSM is accepted into the kernel when its intent (a description of what it tries to protect against and in what cases one would expect to diff --git a/Documentation/security/self-protection.txt b/Documentation/security/self-protection.txt index 3010576c9fca..141acfebe6ef 100644 --- a/Documentation/security/self-protection.txt +++ b/Documentation/security/self-protection.txt @@ -51,11 +51,17 @@ kernel, they are implemented in a way where the memory is temporarily made writable during the update, and then returned to the original permissions.) -In support of this are (the poorly named) CONFIG_DEBUG_RODATA and -CONFIG_DEBUG_SET_MODULE_RONX, which seek to make sure that code is not +In support of this are CONFIG_STRICT_KERNEL_RWX and +CONFIG_STRICT_MODULE_RWX, which seek to make sure that code is not writable, data is not executable, and read-only data is neither writable nor executable. +Most architectures have these options on by default and not user selectable. +For some architectures like arm that wish to have these be selectable, +the architecture Kconfig can select ARCH_OPTIONAL_KERNEL_RWX to enable +a Kconfig prompt. CONFIG_ARCH_OPTIONAL_KERNEL_RWX_DEFAULT determines +the default setting when ARCH_OPTIONAL_KERNEL_RWX is enabled. + #### Function pointers and sensitive variables must not be writable Vast areas of kernel memory contain function pointers that are looked |