Commit 8f44df80 authored by Pedro Tammela's avatar Pedro Tammela Committed by Yongqiang Liu
Browse files

net/netlink: fix NETLINK_LIST_MEMBERSHIPS length report 

stable inclusion
from stable-v4.19.285
commit 16072e1e6ec237c9d8decdce0758f7629c175354
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7J5UF
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=16072e1e6ec237c9d8decdce0758f7629c175354



--------------------------------

[ Upstream commit f4e45348 ]

The current code for the length calculation wrongly truncates the reported
length of the groups array, causing an under report of the subscribed
groups. To fix this, use 'BITS_TO_BYTES()' which rounds up the
division by 8.

Fixes: b42be38b ("netlink: add API to retrieve all group memberships")
Signed-off-by: default avatarPedro Tammela <pctammela@mojatatu.com>
Reviewed-by: default avatarSimon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230529153335.389815-1-pctammela@mojatatu.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Conflicts:
	net/netlink/af_netlink.c
	include/linux/bitops.h
Signed-off-by: default avatarDong Chenchen <dongchenchen2@huawei.com>
Reviewed-by: default avatarYue Haibing <yuehaibing@huawei.com>
Signed-off-by: default avatarYongqiang Liu <liuyongqiang13@huawei.com>
parent 679d13c0

include/linux/bitops.h

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 


#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)

#define BITS_TO_LONGS(nr)	DIV_ROUND_UP(nr, BITS_PER_TYPE(long))

#define BITS_TO_BYTES(nr)       DIV_ROUND_UP(nr, BITS_PER_TYPE(char))



extern unsigned int __sw_hweight8(unsigned int w);

extern unsigned int __sw_hweight16(unsigned int w);

net/netlink/af_netlink.c

+1 −1
Original line number Diff line number Diff line
@@ -1795,7 +1795,7 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, 
				break;

			}

		}

		if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen))

		if (put_user(ALIGN(BITS_TO_BYTES(nlk->ngroups), sizeof(u32)), optlen))

			err = -EFAULT;

		netlink_unlock_table();

		break;