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authorAlexey Gladkov <legion@kernel.org>2021-04-22 14:27:14 +0200
committerEric W. Biederman <ebiederm@xmission.com>2021-04-30 14:14:02 -0500
commitd7c9e99aee48e6bc0b427f3e3c658a6aba15001e (patch)
tree61da3b62f597bf4d3658ce6d3198f7e4ae4ddf37 /kernel
parentd64696905554e919321e31afc210606653b8f6a4 (diff)
downloadlwn-d7c9e99aee48e6bc0b427f3e3c658a6aba15001e.tar.gz
lwn-d7c9e99aee48e6bc0b427f3e3c658a6aba15001e.zip
Reimplement RLIMIT_MEMLOCK on top of ucounts
The rlimit counter is tied to uid in the user_namespace. This allows rlimit values to be specified in userns even if they are already globally exceeded by the user. However, the value of the previous user_namespaces cannot be exceeded. Changelog v11: * Fix issue found by lkp robot. v8: * Fix issues found by lkp-tests project. v7: * Keep only ucounts for RLIMIT_MEMLOCK checks instead of struct cred. v6: * Fix bug in hugetlb_file_setup() detected by trinity. Reported-by: kernel test robot <oliver.sang@intel.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Alexey Gladkov <legion@kernel.org> Link: https://lkml.kernel.org/r/970d50c70c71bfd4496e0e8d2a0a32feebebb350.1619094428.git.legion@kernel.org Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/fork.c1
-rw-r--r--kernel/ucount.c1
-rw-r--r--kernel/user.c1
-rw-r--r--kernel/user_namespace.c1
4 files changed, 3 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 03119926b27d..610fd4de60d7 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -825,6 +825,7 @@ void __init fork_init(void)
init_user_ns.ucount_max[UCOUNT_RLIMIT_NPROC] = task_rlimit(&init_task, RLIMIT_NPROC);
init_user_ns.ucount_max[UCOUNT_RLIMIT_MSGQUEUE] = task_rlimit(&init_task, RLIMIT_MSGQUEUE);
init_user_ns.ucount_max[UCOUNT_RLIMIT_SIGPENDING] = task_rlimit(&init_task, RLIMIT_SIGPENDING);
+ init_user_ns.ucount_max[UCOUNT_RLIMIT_MEMLOCK] = task_rlimit(&init_task, RLIMIT_MEMLOCK);
#ifdef CONFIG_VMAP_STACK
cpuhp_setup_state(CPUHP_BP_PREPARE_DYN, "fork:vm_stack_cache",
diff --git a/kernel/ucount.c b/kernel/ucount.c
index 8ce62da6a62c..d316bac3e520 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -83,6 +83,7 @@ static struct ctl_table user_table[] = {
{ },
{ },
{ },
+ { },
{ }
};
#endif /* CONFIG_SYSCTL */
diff --git a/kernel/user.c b/kernel/user.c
index 6737327f83be..c82399c1618a 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -98,7 +98,6 @@ static DEFINE_SPINLOCK(uidhash_lock);
/* root_user.__count is 1, for init task cred */
struct user_struct root_user = {
.__count = REFCOUNT_INIT(1),
- .locked_shm = 0,
.uid = GLOBAL_ROOT_UID,
.ratelimit = RATELIMIT_STATE_INIT(root_user.ratelimit, 0, 0),
};
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 822eacee4588..892da1360862 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -125,6 +125,7 @@ int create_user_ns(struct cred *new)
ns->ucount_max[UCOUNT_RLIMIT_NPROC] = rlimit(RLIMIT_NPROC);
ns->ucount_max[UCOUNT_RLIMIT_MSGQUEUE] = rlimit(RLIMIT_MSGQUEUE);
ns->ucount_max[UCOUNT_RLIMIT_SIGPENDING] = rlimit(RLIMIT_SIGPENDING);
+ ns->ucount_max[UCOUNT_RLIMIT_MEMLOCK] = rlimit(RLIMIT_MEMLOCK);
ns->ucounts = ucounts;
/* Inherit USERNS_SETGROUPS_ALLOWED from our parent */