mm/mempolicy: fix get_nodes out of bound access

When user specified more nodes than supported, get_nodes will access nmask
array out of bounds.

Link: https://lkml.kernel.org/r/20220601093211.2970565-1-tianyu.li@arm.com
Fixes: e130242dc3 ("mm: simplify compat numa syscalls")
Signed-off-by: Tianyu Li <tianyu.li@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Tianyu Li 2022-06-01 17:32:11 +08:00 committed by akpm
parent 8edaec0756
commit 000eca5d04
1 changed files with 1 additions and 1 deletions

View File

@ -1388,7 +1388,7 @@ static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
unsigned long bits = min_t(unsigned long, maxnode, BITS_PER_LONG);
unsigned long t;
if (get_bitmap(&t, &nmask[maxnode / BITS_PER_LONG], bits))
if (get_bitmap(&t, &nmask[(maxnode - 1) / BITS_PER_LONG], bits))
return -EFAULT;
if (maxnode - bits >= MAX_NUMNODES) {