Since the /proc/pid/attr API was added to the kernel, there have been a couple of changes to the SELinux handling of /proc/pid/attr/current. Fix the SELinux /proc/pid/attr/current example text to reflect these changes and note which kernel versions first included the changes. Signed-off-by: Stephen Smalley <sds@xxxxxxxxxxxxx> --- man5/proc.5 | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/man5/proc.5 b/man5/proc.5 index d01a7a9..68772f3 100644 --- a/man5/proc.5 +++ b/man5/proc.5 @@ -101,13 +101,27 @@ This directory is present only if the kernel was configured with The contents of this file represent the current security attributes of the process. -In SELinux, this file is used to get the security context of a process, -but not to set the security context (a write is always denied), -since SELinux limits process security transitions to +In SELinux, this file is used to get the security context of a process. +Prior to Linux 2.6.11, this file could not be used to set the security +context (a write was always denied), since SELinux limited process security +transitions to .BR execve (2) (see the description of .IR /proc/[pid]/attr/exec , below). +Since Linux 2.6.11, SELinux lifted this restriction and began supporting +"set" operations via writes to this node if authorized by policy, +although use of this operation is only suitable for applications that are +trusted to maintain any desired separation between the old and new security +contexts. Prior to Linux 2.6.28, SELinux did not allow threads within a +multi-threaded process to set their security context via this node +as it would yield an inconsistency among the security contexts of the +threads sharing the same memory space. Since Linux 2.6.28, SELinux lifted +this restriction and began supporting "set" operations for threads within +a multi-threaded process if the new security context is bounded by the old +security context, where the bounded relation is defined in policy and +guarantees that the new security context has a subset of the permissions +of the old security context. Other security modules may choose to support "set" operations via writes to this node. .TP -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
