From: Tianyu Li tianyu.li@arm.com
[ Upstream commit 000eca5d044d1ee23b4ca311793cf3fc528da6c6 ]
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: e130242dc351 ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- mm/mempolicy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 9db0158155e1..4472be6f123d 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1389,7 +1389,7 @@ 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) {