| From e8491b49a14ee281b6a6f69d6f1a690baef3e65f Mon Sep 17 00:00:00 2001 |
| From: YueHaibing <yuehaibing@huawei.com> |
| Date: Thu, 28 Feb 2019 15:18:59 +0800 |
| Subject: xfrm: policy: Fix out-of-bound array accesses in __xfrm_policy_unlink |
| |
| [ Upstream commit b805d78d300bcf2c83d6df7da0c818b0fee41427 ] |
| |
| UBSAN report this: |
| |
| UBSAN: Undefined behaviour in net/xfrm/xfrm_policy.c:1289:24 |
| index 6 is out of range for type 'unsigned int [6]' |
| CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.162-514.55.6.9.x86_64+ #13 |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 |
| 0000000000000000 1466cf39b41b23c9 ffff8801f6b07a58 ffffffff81cb35f4 |
| 0000000041b58ab3 ffffffff83230f9c ffffffff81cb34e0 ffff8801f6b07a80 |
| ffff8801f6b07a20 1466cf39b41b23c9 ffffffff851706e0 ffff8801f6b07ae8 |
| Call Trace: |
| <IRQ> [<ffffffff81cb35f4>] __dump_stack lib/dump_stack.c:15 [inline] |
| <IRQ> [<ffffffff81cb35f4>] dump_stack+0x114/0x1a0 lib/dump_stack.c:51 |
| [<ffffffff81d94225>] ubsan_epilogue+0x12/0x8f lib/ubsan.c:164 |
| [<ffffffff81d954db>] __ubsan_handle_out_of_bounds+0x16e/0x1b2 lib/ubsan.c:382 |
| [<ffffffff82a25acd>] __xfrm_policy_unlink+0x3dd/0x5b0 net/xfrm/xfrm_policy.c:1289 |
| [<ffffffff82a2e572>] xfrm_policy_delete+0x52/0xb0 net/xfrm/xfrm_policy.c:1309 |
| [<ffffffff82a3319b>] xfrm_policy_timer+0x30b/0x590 net/xfrm/xfrm_policy.c:243 |
| [<ffffffff813d3927>] call_timer_fn+0x237/0x990 kernel/time/timer.c:1144 |
| [<ffffffff813d8e7e>] __run_timers kernel/time/timer.c:1218 [inline] |
| [<ffffffff813d8e7e>] run_timer_softirq+0x6ce/0xb80 kernel/time/timer.c:1401 |
| [<ffffffff8120d6f9>] __do_softirq+0x299/0xe10 kernel/softirq.c:273 |
| [<ffffffff8120e676>] invoke_softirq kernel/softirq.c:350 [inline] |
| [<ffffffff8120e676>] irq_exit+0x216/0x2c0 kernel/softirq.c:391 |
| [<ffffffff82c5edab>] exiting_irq arch/x86/include/asm/apic.h:652 [inline] |
| [<ffffffff82c5edab>] smp_apic_timer_interrupt+0x8b/0xc0 arch/x86/kernel/apic/apic.c:926 |
| [<ffffffff82c5c985>] apic_timer_interrupt+0xa5/0xb0 arch/x86/entry/entry_64.S:735 |
| <EOI> [<ffffffff81188096>] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:52 |
| [<ffffffff810834d7>] arch_safe_halt arch/x86/include/asm/paravirt.h:111 [inline] |
| [<ffffffff810834d7>] default_idle+0x27/0x430 arch/x86/kernel/process.c:446 |
| [<ffffffff81085f05>] arch_cpu_idle+0x15/0x20 arch/x86/kernel/process.c:437 |
| [<ffffffff8132abc3>] default_idle_call+0x53/0x90 kernel/sched/idle.c:92 |
| [<ffffffff8132b32d>] cpuidle_idle_call kernel/sched/idle.c:156 [inline] |
| [<ffffffff8132b32d>] cpu_idle_loop kernel/sched/idle.c:251 [inline] |
| [<ffffffff8132b32d>] cpu_startup_entry+0x60d/0x9a0 kernel/sched/idle.c:299 |
| [<ffffffff8113e119>] start_secondary+0x3c9/0x560 arch/x86/kernel/smpboot.c:245 |
| |
| The issue is triggered as this: |
| |
| xfrm_add_policy |
| -->verify_newpolicy_info //check the index provided by user with XFRM_POLICY_MAX |
| //In my case, the index is 0x6E6BB6, so it pass the check. |
| -->xfrm_policy_construct //copy the user's policy and set xfrm_policy_timer |
| -->xfrm_policy_insert |
| --> __xfrm_policy_link //use the orgin dir, in my case is 2 |
| --> xfrm_gen_index //generate policy index, there is 0x6E6BB6 |
| |
| then xfrm_policy_timer be fired |
| |
| xfrm_policy_timer |
| --> xfrm_policy_id2dir //get dir from (policy index & 7), in my case is 6 |
| --> xfrm_policy_delete |
| --> __xfrm_policy_unlink //access policy_count[dir], trigger out of range access |
| |
| Add xfrm_policy_id2dir check in verify_newpolicy_info, make sure the computed dir is |
| valid, to fix the issue. |
| |
| Reported-by: Hulk Robot <hulkci@huawei.com> |
| Fixes: e682adf021be ("xfrm: Try to honor policy index if it's supplied by user") |
| Signed-off-by: YueHaibing <yuehaibing@huawei.com> |
| Acked-by: Herbert Xu <herbert@gondor.apana.org.au> |
| Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| net/xfrm/xfrm_user.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c |
| index f6f91c3b2de02..ca5c79bfd9a5e 100644 |
| --- a/net/xfrm/xfrm_user.c |
| +++ b/net/xfrm/xfrm_user.c |
| @@ -1344,7 +1344,7 @@ static int verify_newpolicy_info(struct xfrm_userpolicy_info *p) |
| ret = verify_policy_dir(p->dir); |
| if (ret) |
| return ret; |
| - if (p->index && ((p->index & XFRM_POLICY_MAX) != p->dir)) |
| + if (p->index && (xfrm_policy_id2dir(p->index) != p->dir)) |
| return -EINVAL; |
| |
| return 0; |
| -- |
| 2.20.1 |
| |