On Mon 09-08-21 15:43:56, Eric W. Biederman 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.
>
> v4 - Made the min and max constants long so the sysctl values
> are actually settable on little endian machines.
> -- EWB
>
> Fixes: f9c82a4ea89c ("Increase size of ucounts to atomic_long_t")
> Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
> Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> Tested-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> Acked-by: Alexey Gladkov <legion@xxxxxxxxxx>
> v1: https://lkml.kernel.org/r/20210721115800.910778-1-svens@xxxxxxxxxxxxx
> v2: https://lkml.kernel.org/r/20210721125233.1041429-1-svens@xxxxxxxxxxxxx
> v3: https://lkml.kernel.org/r/20210730062854.3601635-1-svens@xxxxxxxxxxxxx
> Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
>
> Thanks everyone for testing and helping find the cause of this bug. I
> will push this out to linux-next shortly.
>
> fs/notify/fanotify/fanotify_user.c | 17 +++++++++++------
> fs/notify/inotify/inotify_user.c | 17 +++++++++++------
> kernel/ucount.c | 19 +++++++++++--------
> 3 files changed, 33 insertions(+), 20 deletions(-)
>
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index 64864fb40b40..28b67cb9458d 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -54,22 +54,27 @@ static int fanotify_max_queued_events __read_mostly;
>
> #include <linux/sysctl.h>
>
> +static long ft_zero = 0;
> +static long ft_int_max = INT_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,
> - .extra1 = SYSCTL_ZERO,
> + .proc_handler = proc_doulongvec_minmax,
> + .extra1 = &ft_zero,
> + .extra2 = &ft_int_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,
> - .extra1 = SYSCTL_ZERO,
> + .proc_handler = proc_doulongvec_minmax,
> + .extra1 = &ft_zero,
> + .extra2 = &ft_int_max,
> },
> {
> .procname = "max_queued_events",
> diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
> index 98f61b31745a..62051247f6d2 100644
> --- a/fs/notify/inotify/inotify_user.c
> +++ b/fs/notify/inotify/inotify_user.c
> @@ -55,22 +55,27 @@ struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
>
> #include <linux/sysctl.h>
>
> +static long it_zero = 0;
> +static long it_int_max = INT_MAX;
> +
> struct ctl_table inotify_table[] = {
> {
> .procname = "max_user_instances",
> .data = &init_user_ns.ucount_max[UCOUNT_INOTIFY_INSTANCES],
> - .maxlen = sizeof(int),
> + .maxlen = sizeof(long),
> .mode = 0644,
> - .proc_handler = proc_dointvec_minmax,
> - .extra1 = SYSCTL_ZERO,
> + .proc_handler = proc_doulongvec_minmax,
> + .extra1 = &it_zero,
> + .extra2 = &it_int_max,
> },
> {
> .procname = "max_user_watches",
> .data = &init_user_ns.ucount_max[UCOUNT_INOTIFY_WATCHES],
> - .maxlen = sizeof(int),
> + .maxlen = sizeof(long),
> .mode = 0644,
> - .proc_handler = proc_dointvec_minmax,
> - .extra1 = SYSCTL_ZERO,
> + .proc_handler = proc_doulongvec_minmax,
> + .extra1 = &it_zero,
> + .extra2 = &it_int_max,
> },
> {
> .procname = "max_queued_events",
> diff --git a/kernel/ucount.c b/kernel/ucount.c
> index 77be3bbe3cc4..bb51849e6375 100644
> --- a/kernel/ucount.c
> +++ b/kernel/ucount.c
> @@ -58,14 +58,17 @@ 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 long ue_zero = 0;
> +static long ue_int_max = INT_MAX;
> +
> +#define UCOUNT_ENTRY(name) \
> + { \
> + .procname = name, \
> + .maxlen = sizeof(long), \
> + .mode = 0644, \
> + .proc_handler = proc_doulongvec_minmax, \
> + .extra1 = &ue_zero, \
> + .extra2 = &ue_int_max, \
> }
> static struct ctl_table user_table[] = {
> UCOUNT_ENTRY("max_user_namespaces"),
> --
> 2.20.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
