Messages in this thread | | | Date | Wed, 21 Jul 2021 14:43:01 +0200 | From | Alexey Gladkov <> | Subject | Re: [PATCH] ucounts: add missing data type changes |
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On Wed, Jul 21, 2021 at 02:32:38PM +0200, Sven Schnelle wrote: > 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?
Yes.
> >> } > >> 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 > >> >
-- Rgrds, legion
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