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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-02 16:20:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-02 16:20:04 -0800
commit5859a2b1991101d6b978f3feb5325dad39421f29 (patch)
tree6455b735d460a0e7a07a45f4aca561745bd72310 /kernel
parent7e3d76139b5da7f58bda13c485e8e208ffce5c9c (diff)
parent0ac983f512033cb7b5e210c9589768ad25b1e36b (diff)
Merge branch 'ucount-rlimit-fixes-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ucounts fix from Eric Biederman: "Etienne Dechamps recently found a regression caused by enforcing RLIMIT_NPROC for root where the rlimit was not previously enforced. Michal Koutný had previously pointed out the inconsistency in enforcing the RLIMIT_NPROC that had been on the root owned process after the root user creates a user namespace. Which makes the fix for the regression simply removing the inconsistency" * 'ucount-rlimit-fixes-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ucounts: Fix systemd LimitNPROC with private users regression
Diffstat (limited to 'kernel')
-rw-r--r--kernel/user_namespace.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 6b2e3ca7ee99..5481ba44a8d6 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -58,6 +58,18 @@ static void set_cred_user_ns(struct cred *cred, struct user_namespace *user_ns)
cred->user_ns = user_ns;
}
+static unsigned long enforced_nproc_rlimit(void)
+{
+ unsigned long limit = RLIM_INFINITY;
+
+ /* Is RLIMIT_NPROC currently enforced? */
+ if (!uid_eq(current_uid(), GLOBAL_ROOT_UID) ||
+ (current_user_ns() != &init_user_ns))
+ limit = rlimit(RLIMIT_NPROC);
+
+ return limit;
+}
+
/*
* Create a new user namespace, deriving the creator from the user in the
* passed credentials, and replacing that user with the new root user for the
@@ -122,7 +134,7 @@ int create_user_ns(struct cred *new)
for (i = 0; i < MAX_PER_NAMESPACE_UCOUNTS; i++) {
ns->ucount_max[i] = INT_MAX;
}
- set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC));
+ set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_NPROC, enforced_nproc_rlimit());
set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_MSGQUEUE, rlimit(RLIMIT_MSGQUEUE));
set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_SIGPENDING, rlimit(RLIMIT_SIGPENDING));
set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_MEMLOCK, rlimit(RLIMIT_MEMLOCK));