diff options
Diffstat (limited to '0001-add-sysctl-to-disallow-unprivileged-CLONE_NEWUSER-by.patch')
| -rw-r--r-- | 0001-add-sysctl-to-disallow-unprivileged-CLONE_NEWUSER-by.patch | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/0001-add-sysctl-to-disallow-unprivileged-CLONE_NEWUSER-by.patch b/0001-add-sysctl-to-disallow-unprivileged-CLONE_NEWUSER-by.patch new file mode 100644 index 000000000000..29582c2bf608 --- /dev/null +++ b/0001-add-sysctl-to-disallow-unprivileged-CLONE_NEWUSER-by.patch @@ -0,0 +1,102 @@ +From 5ec2dd3a095442ec1a21d86042a4994f2ba24e63 Mon Sep 17 00:00:00 2001 +Message-Id: <5ec2dd3a095442ec1a21d86042a4994f2ba24e63.1512651251.git.jan.steffens@gmail.com> +From: Serge Hallyn <serge.hallyn@canonical.com> +Date: Fri, 31 May 2013 19:12:12 +0100 +Subject: [PATCH] add sysctl to disallow unprivileged CLONE_NEWUSER by default + +Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> +[bwh: Remove unneeded binary sysctl bits] +Signed-off-by: Daniel Micay <danielmicay@gmail.com> +--- + kernel/fork.c | 15 +++++++++++++++ + kernel/sysctl.c | 12 ++++++++++++ + kernel/user_namespace.c | 3 +++ + 3 files changed, 30 insertions(+) + +diff --git a/kernel/fork.c b/kernel/fork.c +index 07cc743698d3668e..4011d68a8ff9305c 100644 +--- a/kernel/fork.c ++++ b/kernel/fork.c +@@ -102,6 +102,11 @@ + + #define CREATE_TRACE_POINTS + #include <trace/events/task.h> ++#ifdef CONFIG_USER_NS ++extern int unprivileged_userns_clone; ++#else ++#define unprivileged_userns_clone 0 ++#endif + + /* + * Minimum number of threads to boot the kernel +@@ -1555,6 +1560,10 @@ static __latent_entropy struct task_struct *copy_process( + if ((clone_flags & (CLONE_NEWUSER|CLONE_FS)) == (CLONE_NEWUSER|CLONE_FS)) + return ERR_PTR(-EINVAL); + ++ if ((clone_flags & CLONE_NEWUSER) && !unprivileged_userns_clone) ++ if (!capable(CAP_SYS_ADMIN)) ++ return ERR_PTR(-EPERM); ++ + /* + * Thread groups must share signals as well, and detached threads + * can only be started up within the thread group. +@@ -2348,6 +2357,12 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) + if (unshare_flags & CLONE_NEWNS) + unshare_flags |= CLONE_FS; + ++ if ((unshare_flags & CLONE_NEWUSER) && !unprivileged_userns_clone) { ++ err = -EPERM; ++ if (!capable(CAP_SYS_ADMIN)) ++ goto bad_unshare_out; ++ } ++ + err = check_unshare_flags(unshare_flags); + if (err) + goto bad_unshare_out; +diff --git a/kernel/sysctl.c b/kernel/sysctl.c +index b86520ed3fb60fbf..f7dab3760839f1a1 100644 +--- a/kernel/sysctl.c ++++ b/kernel/sysctl.c +@@ -105,6 +105,9 @@ extern int core_uses_pid; + extern char core_pattern[]; + extern unsigned int core_pipe_limit; + #endif ++#ifdef CONFIG_USER_NS ++extern int unprivileged_userns_clone; ++#endif + extern int pid_max; + extern int pid_max_min, pid_max_max; + extern int percpu_pagelist_fraction; +@@ -513,6 +516,15 @@ static struct ctl_table kern_table[] = { + .proc_handler = proc_dointvec, + }, + #endif ++#ifdef CONFIG_USER_NS ++ { ++ .procname = "unprivileged_userns_clone", ++ .data = &unprivileged_userns_clone, ++ .maxlen = sizeof(int), ++ .mode = 0644, ++ .proc_handler = proc_dointvec, ++ }, ++#endif + #ifdef CONFIG_PROC_SYSCTL + { + .procname = "tainted", +diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c +index c490f1e4313b998a..dd03bd39d7bf194d 100644 +--- a/kernel/user_namespace.c ++++ b/kernel/user_namespace.c +@@ -24,6 +24,9 @@ + #include <linux/projid.h> + #include <linux/fs_struct.h> + ++/* sysctl */ ++int unprivileged_userns_clone; ++ + static struct kmem_cache *user_ns_cachep __read_mostly; + static DEFINE_MUTEX(userns_state_mutex); + +-- +2.15.1 + |