KASAN: slab-out-of-bounds Read in xfrm_lookup_with

KASAN: slab-out-of-bounds Read in xfrm_lookup_with_ifid
Status: upstream: reported on 2020/01/10 17:14
Reported-by: syzbot+18bd12c034e089442dc1@syzkaller.appspotmail.com
First crash: 142d, last: 8d21h

Sample crash report:

==================================================================
BUG: KASAN: slab-out-of-bounds in xfrm_lookup_with_ifid+0x1e23/0x2150 net/xfrm/xfrm_policy.c:3083
Read of size 4 at addr ffff88809f27d6a4 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382
 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511
 kasan_report+0x33/0x50 mm/kasan/common.c:625
 xfrm_lookup_with_ifid+0x1e23/0x2150 net/xfrm/xfrm_policy.c:3083
 xfrmi_xmit2 net/xfrm/xfrm_interface.c:272 [inline]
 xfrmi_xmit+0x3c1/0x1430 net/xfrm/xfrm_interface.c:387
 __netdev_start_xmit include/linux/netdevice.h:4533 [inline]
 netdev_start_xmit include/linux/netdevice.h:4547 [inline]
 xmit_one net/core/dev.c:3477 [inline]
 dev_hard_start_xmit+0x1a4/0x9b0 net/core/dev.c:3493
 __dev_queue_xmit+0x25e1/0x30a0 net/core/dev.c:4052
 neigh_output include/net/neighbour.h:510 [inline]
 ip6_finish_output2+0x1091/0x25b0 net/ipv6/ip6_output.c:117
 __ip6_finish_output+0x442/0xab0 net/ipv6/ip6_output.c:143
 ip6_finish_output+0x34/0x1f0 net/ipv6/ip6_output.c:153
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x239/0x810 net/ipv6/ip6_output.c:176
 dst_output include/net/dst.h:435 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ndisc_send_skb+0xf40/0x14b0 net/ipv6/ndisc.c:506
 ndisc_send_rs+0x12e/0x6f0 net/ipv6/ndisc.c:700
 addrconf_rs_timer+0x30f/0x6e0 net/ipv6/addrconf.c:3889
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1405
 expire_timers kernel/time/timer.c:1450 [inline]
 __run_timers kernel/time/timer.c:1774 [inline]
 __run_timers kernel/time/timer.c:1741 [inline]
 run_timer_softirq+0x623/0x1600 kernel/time/timer.c:1787
 __do_softirq+0x26c/0x9f7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x192/0x1d0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:546 [inline]
 smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1140
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: cc cc cc cc cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 04 44 58 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d f4 43 58 00 fb f4 <c3> cc 41 56 41 55 41 54 55 53 e8 83 bc 90 f9 e8 9e 98 c9 fb 0f 1f
RSP: 0018:ffffffff89807d98 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1329807 RBX: ffffffff898864c0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff89886d84
RBP: dffffc0000000000 R08: ffffffff898864c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff1310c98
R13: 0000000000000000 R14: ffffffff8a894ec0 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:144 [inline]
 default_idle+0x49/0x350 arch/x86/kernel/process.c:697
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x393/0x690 kernel/sched/idle.c:269
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
 start_kernel+0x862/0x89c init/main.c:1003
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

Allocated by task 4115:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc mm/kasan/common.c:495 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468
 slab_post_alloc_hook mm/slab.h:586 [inline]
 slab_alloc mm/slab.c:3320 [inline]
 kmem_cache_alloc+0x11b/0x740 mm/slab.c:3484
 getname_flags fs/namei.c:138 [inline]
 getname_flags+0xd2/0x5b0 fs/namei.c:128
 do_sys_openat2+0x3fc/0x7d0 fs/open.c:1142
 do_sys_open+0xc3/0x140 fs/open.c:1164
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 4115:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 kasan_set_free_info mm/kasan/common.c:317 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456
 __cache_free mm/slab.c:3426 [inline]
 kmem_cache_free+0x7f/0x320 mm/slab.c:3694
 putname+0xe1/0x120 fs/namei.c:259
 do_sys_openat2+0x467/0x7d0 fs/open.c:1157
 do_sys_open+0xc3/0x140 fs/open.c:1164
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff88809f27c540
 which belongs to the cache names_cache of size 4096
The buggy address is located 356 bytes to the right of
 4096-byte region [ffff88809f27c540, ffff88809f27d540)
The buggy address belongs to the page:
page:ffffea00027c9f00 refcount:1 mapcount:0 mapping:00000000c9c7d1a0 index:0x0 head:ffffea00027c9f00 order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea00017eca88 ffffea000260f188 ffff8880aa1eb000
raw: 0000000000000000 ffff88809f27c540 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809f27d580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809f27d600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88809f27d680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff88809f27d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809f27d780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (8):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Maintainers
ci-upstream-net-this-kasan-gce	2020/05/05 05:49	net	8d9f73c0	9941337c	.config	log	report	davem@davemloft.net, herbert@gondor.apana.org.au, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com
ci-upstream-net-this-kasan-gce	2020/02/15 04:50	net	a1fa83bd	5d7b90f1	.config	log	report	davem@davemloft.net, herbert@gondor.apana.org.au, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com
ci-upstream-net-this-kasan-gce	2020/01/19 13:28	net	e02d9c4c	bc8bc756	.config	log	report	davem@davemloft.net, herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com
ci-upstream-net-this-kasan-gce	2020/01/13 04:43	net	c9f53049	53faa9fe	.config	log	report	davem@davemloft.net, herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com
ci-upstream-net-kasan-gce	2020/05/21 21:55	net-next	de1b99ef	1f30020f	.config	log	report	davem@davemloft.net, herbert@gondor.apana.org.au, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com
ci-upstream-net-kasan-gce	2020/04/03 16:44	net-next	1a323ea5	5ed396e6	.config	log	report	davem@davemloft.net, herbert@gondor.apana.org.au, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com
ci-upstream-net-kasan-gce	2020/01/11 09:24	net-next	9f120e76	4de4e9f0	.config	log	report	davem@davemloft.net, herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com
ci-upstream-net-kasan-gce	2020/01/09 19:24	net-next	4a4a52d4	4de4e9f0	.config	log	report	davem@davemloft.net, herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com