Commit 4c3ea889 authored by Anastasia Kovaleva's avatar Anastasia Kovaleva Committed by Wen Zhiwei
Browse files

net: Fix an unsafe loop on the list 

stable inclusion
from stable-v6.6.57
commit 3be342e0332a7c83eb26fbb22bf156fdca467a5d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IB2M97

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3be342e0332a7c83eb26fbb22bf156fdca467a5d



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

commit 1dae9f1187189bc09ff6d25ca97ead711f7e26f9 upstream.

The kernel may crash when deleting a genetlink family if there are still
listeners for that family:

Oops: Kernel access of bad area, sig: 11 [#1]
  ...
  NIP [c000000000c080bc] netlink_update_socket_mc+0x3c/0xc0
  LR [c000000000c0f764] __netlink_clear_multicast_users+0x74/0xc0
  Call Trace:
__netlink_clear_multicast_users+0x74/0xc0
genl_unregister_family+0xd4/0x2d0

Change the unsafe loop on the list to a safe one, because inside the
loop there is an element removal from this list.

Fixes: b8273570 ("genetlink: fix netns vs. netlink table locking (2)")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarAnastasia Kovaleva <a.kovaleva@yadro.com>
Reviewed-by: default avatarDmitry Bogdanov <d.bogdanov@yadro.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241003104431.12391-1-a.kovaleva@yadro.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarWen Zhiwei <wenzhiwei@kylinos.cn>
parent 983c69ef

include/net/sock.h

+2 −0
Original line number Diff line number Diff line
@@ -919,6 +919,8 @@ static inline void sk_add_bind2_node(struct sock *sk, struct hlist_head *list) 
	hlist_for_each_entry(__sk, list, sk_bind_node)

#define sk_for_each_bound_bhash2(__sk, list) \

	hlist_for_each_entry(__sk, list, sk_bind2_node)

#define sk_for_each_bound_safe(__sk, tmp, list) \

	hlist_for_each_entry_safe(__sk, tmp, list, sk_bind_node)



/**

 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset

net/netlink/af_netlink.c

+2 −1
Original line number Diff line number Diff line
@@ -2147,8 +2147,9 @@ void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) 
{

	struct sock *sk;

	struct netlink_table *tbl = &nl_table[ksk->sk_protocol];

	struct hlist_node *tmp;



	sk_for_each_bound(sk, &tbl->mc_list)

	sk_for_each_bound_safe(sk, tmp, &tbl->mc_list)

		netlink_update_socket_mc(nlk_sk(sk), group, 0);

}