[PATCH] ucounts: add missing data type changes

From: Sven Schnelle
Date: Wed Jul 21 2021 - 08:04:08 EST


commit f9c82a4ea89c3 ("Increase size of ucounts to atomic_long_t")
changed the data type of ucounts/ucounts_max to long, but missed to
adjust a few other places. This is noticeable on big endian platforms
from user space because the /proc/sys/user/max_*_names files all
contain 0.

Fixes: f9c82a4ea89c ("Increase size of ucounts to atomic_long_t")
Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
---
fs/notify/fanotify/fanotify_user.c | 11 +++++++----
kernel/ucount.c | 18 ++++++++++--------
kernel/user_namespace.c | 2 +-
3 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 64864fb40b40..995379ddce86 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -54,22 +54,25 @@ static int fanotify_max_queued_events __read_mostly;

#include <linux/sysctl.h>

+static unsigned long long_max = LONG_MAX;
struct ctl_table fanotify_table[] = {
{
.procname = "max_user_groups",
.data = &init_user_ns.ucount_max[UCOUNT_FANOTIFY_GROUPS],
- .maxlen = sizeof(int),
+ .maxlen = sizeof(long),
.mode = 0644,
- .proc_handler = proc_dointvec_minmax,
+ .proc_handler = proc_doulongvec_minmax,
.extra1 = SYSCTL_ZERO,
+ .extra2 = &long_max,
},
{
.procname = "max_user_marks",
.data = &init_user_ns.ucount_max[UCOUNT_FANOTIFY_MARKS],
- .maxlen = sizeof(int),
+ .maxlen = sizeof(long),
.mode = 0644,
- .proc_handler = proc_dointvec_minmax,
+ .proc_handler = proc_doulongvec_minmax,
.extra1 = SYSCTL_ZERO,
+ .extra2 = &long_max,
},
{
.procname = "max_queued_events",
diff --git a/kernel/ucount.c b/kernel/ucount.c
index 87799e2379bd..681ea1b1a06f 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -58,14 +58,16 @@ static struct ctl_table_root set_root = {
.permissions = set_permissions,
};

-#define UCOUNT_ENTRY(name) \
- { \
- .procname = name, \
- .maxlen = sizeof(int), \
- .mode = 0644, \
- .proc_handler = proc_dointvec_minmax, \
- .extra1 = SYSCTL_ZERO, \
- .extra2 = SYSCTL_INT_MAX, \
+static unsigned long long_max = LONG_MAX;
+
+#define UCOUNT_ENTRY(name) \
+ { \
+ .procname = name, \
+ .maxlen = sizeof(long), \
+ .mode = 0644, \
+ .proc_handler = proc_doulongvec_minmax, \
+ .extra1 = SYSCTL_ZERO, \
+ .extra2 = &long_max, \
}
static struct ctl_table user_table[] = {
UCOUNT_ENTRY("max_user_namespaces"),
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index ef82d401dde8..d8ad4c261253 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -120,7 +120,7 @@ int create_user_ns(struct cred *new)
ns->group = group;
INIT_WORK(&ns->work, free_user_ns);
for (i = 0; i < MAX_PER_NAMESPACE_UCOUNTS; i++) {
- ns->ucount_max[i] = INT_MAX;
+ ns->ucount_max[i] = LONG_MAX;
}
set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC));
set_rlimit_ucount_max(ns, UCOUNT_RLIMIT_MSGQUEUE, rlimit(RLIMIT_MSGQUEUE));
--
2.25.1