diff options
| author | Chen Zhongjin <chenzhongjin@huawei.com> | 2022-11-01 20:15:52 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-11-02 20:44:27 -0700 |
| commit | f8017317cb0b279b8ab98b0f3901a2e0ac880dad (patch) | |
| tree | f839663564156b80ef5ddd79302b722dd3b2ba27 /net | |
| parent | 62ff373da2534534c55debe6c724c7fe14adb97f (diff) | |
net, neigh: Fix null-ptr-deref in neigh_table_clear()
When IPv6 module gets initialized but hits an error in the middle,
kenel panic with:
KASAN: null-ptr-deref in range [0x0000000000000598-0x000000000000059f]
CPU: 1 PID: 361 Comm: insmod
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:__neigh_ifdown.isra.0+0x24b/0x370
RSP: 0018:ffff888012677908 EFLAGS: 00000202
...
Call Trace:
<TASK>
neigh_table_clear+0x94/0x2d0
ndisc_cleanup+0x27/0x40 [ipv6]
inet6_init+0x21c/0x2cb [ipv6]
do_one_initcall+0xd3/0x4d0
do_init_module+0x1ae/0x670
...
Kernel panic - not syncing: Fatal exception
When ipv6 initialization fails, it will try to cleanup and calls:
neigh_table_clear()
neigh_ifdown(tbl, NULL)
pneigh_queue_purge(&tbl->proxy_queue, dev_net(dev == NULL))
# dev_net(NULL) triggers null-ptr-deref.
Fix it by passing NULL to pneigh_queue_purge() in neigh_ifdown() if dev
is NULL, to make kernel not panic immediately.
Fixes: 66ba215cb513 ("neigh: fix possible DoS due to net iface start/stop loop")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Link: https://lore.kernel.org/r/20221101121552.21890-1-chenzhongjin@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/neighbour.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 3c4786b99907..a77a85e357e0 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -409,7 +409,7 @@ static int __neigh_ifdown(struct neigh_table *tbl, struct net_device *dev, write_lock_bh(&tbl->lock); neigh_flush_dev(tbl, dev, skip_perm); pneigh_ifdown_and_unlock(tbl, dev); - pneigh_queue_purge(&tbl->proxy_queue, dev_net(dev)); + pneigh_queue_purge(&tbl->proxy_queue, dev ? dev_net(dev) : NULL); if (skb_queue_empty_lockless(&tbl->proxy_queue)) del_timer_sync(&tbl->proxy_timer); return 0; |