From 68a5def1d2c8fa495d8ac010d3762615b5e2c820 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Fri, 16 Sep 2022 11:48:21 +0300 Subject: [PATCH] ipv6: Fix crash when IPv6 is administratively disabled [ Upstream commit 76dd07281338da6951fdab3432ced843fa87839c ] The global 'raw_v6_hashinfo' variable can be accessed even when IPv6 is administratively disabled via the 'ipv6.disable=1' kernel command line option, leading to a crash [1]. Fix by restoring the original behavior and always initializing the variable, regardless of IPv6 support being administratively disabled or not. [1] BUG: unable to handle page fault for address: ffffffffffffffc8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 173e18067 P4D 173e18067 PUD 173e1a067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 3 PID: 271 Comm: ss Not tainted 6.0.0-rc4-custom-00136-g0727a9a5fbc1 #1396 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 RIP: 0010:raw_diag_dump+0x310/0x7f0 [...] Call Trace: __inet_diag_dump+0x10f/0x2e0 netlink_dump+0x575/0xfd0 __netlink_dump_start+0x67b/0x940 inet_diag_handler_cmd+0x273/0x2d0 sock_diag_rcv_msg+0x317/0x440 netlink_rcv_skb+0x15e/0x430 sock_diag_rcv+0x2b/0x40 netlink_unicast+0x53b/0x800 netlink_sendmsg+0x945/0xe60 ____sys_sendmsg+0x747/0x960 ___sys_sendmsg+0x13a/0x1e0 __sys_sendmsg+0x118/0x1e0 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Fixes: 0daf07e52709 ("raw: convert raw sockets to RCU") Reported-by: Roberto Ricci Tested-by: Roberto Ricci Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20220916084821.229287-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/af_inet6.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 9f6f4a41245d..1012012a061f 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -1069,13 +1069,13 @@ static int __init inet6_init(void) for (r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r) INIT_LIST_HEAD(r); + raw_hashinfo_init(&raw_v6_hashinfo); + if (disable_ipv6_mod) { pr_info("Loaded, but administratively disabled, reboot required to enable\n"); goto out; } - raw_hashinfo_init(&raw_v6_hashinfo); - err = proto_register(&tcpv6_prot, 1); if (err) goto out; -- 2.44.0