Messages in this thread | | | From | Sven Schnelle <> | Subject | Re: [PATCH] ucounts: add missing data type changes | Date | Wed, 21 Jul 2021 14:32:38 +0200 |
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Alexey Gladkov <legion@kernel.org> writes:
> On Wed, Jul 21, 2021 at 01:58:00PM +0200, Sven Schnelle wrote: >> 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. > > I didn't increase them because I didn't want to increase the maximum > number of namespaces. > > Your patch not only fixes the described problem, but also increases the > maximum number of namespaces. > >> Fixes: f9c82a4ea89c ("Increase size of ucounts to atomic_long_t") >> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> >> --- >> 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; > > I think this should be INT_MAX.
Thanks. I'll change the code to use SYSCTL_INT_MAX instead and send a v2.
>> 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;
Guess this should also stay at INT_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 >>
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