5.4-stable review patch. If anyone has any objections, please let me know.
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From: Al Viro viro@zeniv.linux.org.uk
commit 046667c4d3196938e992fba0dfcde570aa85cd0e upstream.
we are *not* guaranteed that anything past the terminating NUL is mapped (let alone initialized with anything sane).
Fixes: 0dea116876ee ("cgroup: implement eventfd-based generic API for notifications") Cc: stable@vger.kernel.org Cc: Andrew Morton akpm@linux-foundation.org Acked-by: Michal Hocko mhocko@suse.com Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/memcontrol.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4732,9 +4732,12 @@ static ssize_t memcg_write_event_control buf = endp + 1;
cfd = simple_strtoul(buf, &endp, 10); - if ((*endp != ' ') && (*endp != '\0')) + if (*endp == '\0') + buf = endp; + else if (*endp == ' ') + buf = endp + 1; + else return -EINVAL; - buf = endp + 1;
event = kzalloc(sizeof(*event), GFP_KERNEL); if (!event)