| Message ID | 20221101121552.21890-1-chenzhongjin@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | f8017317cb0b279b8ab98b0f3901a2e0ac880dad |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] net, neigh: Fix null-ptr-deref in neigh_table_clear() | expand |
On Tue, Nov 1, 2022 at 5:19 AM Chen Zhongjin <chenzhongjin@huawei.com> wrote: > > 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> > --- SGTM, thanks ! Reviewed-by: Eric Dumazet <edumazet@google.com>
On 11/1/22 13:15, Chen Zhongjin wrote: > 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> > --- > net/core/neighbour.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > 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; Reviewed-by: Denis V. Lunev <den@openvz.org>
Hello: This patch was applied to netdev/net.git (master) by Jakub Kicinski <kuba@kernel.org>: On Tue, 1 Nov 2022 20:15:52 +0800 you wrote: > 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 > > [...] Here is the summary with links: - [net] net, neigh: Fix null-ptr-deref in neigh_table_clear() https://git.kernel.org/netdev/net/c/f8017317cb0b You are awesome, thank you!
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;
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> --- net/core/neighbour.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)