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KASAN: use-after-free Read in rawv6_sendmsg

Status: fixed on 2018/10/11 14:33
Subsystems: net
[Documentation on labels]
Fix commit: a688caa34beb net-backports: ipv6: take rcu lock in rawv6_send_hdrinc()
First crash: 2476d, last: 2444d
▶ ▼ Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 KASAN: use-after-free Read in rawv6_sendmsg syz 3 2488d 2257d 0/3 public: reported syz repro on 2019/04/14 09:28

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in rawv6_send_hdrinc net/ipv6/raw.c:692 [inline]
BUG: KASAN: use-after-free in rawv6_sendmsg+0x4421/0x4630 net/ipv6/raw.c:921
Read of size 8 at addr ffff8801c1310c70 by task syz-executor645/20842

CPU: 1 PID: 20842 Comm: syz-executor645 Not tainted 4.19.0-rc3+ #231
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 rawv6_send_hdrinc net/ipv6/raw.c:692 [inline]
 rawv6_sendmsg+0x4421/0x4630 net/ipv6/raw.c:921
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:631
 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2114
 __sys_sendmsg+0x11d/0x280 net/socket.c:2152
 __do_sys_sendmsg net/socket.c:2161 [inline]
 __se_sys_sendmsg net/socket.c:2159 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2159
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443759
Code: e8 bc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 bb 02 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffebd1ec3d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000443759
RDX: 0000000000000000 RSI: 0000000020003840 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000a0a R09: 0000000000000a0a
R10: 0000000000000004 R11: 0000000000000246 R12: 000000000000091d
R13: 00000000000f8d82 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 20842:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554
 dst_alloc+0xbb/0x1d0 net/core/dst.c:105
 ip6_dst_alloc+0x35/0xa0 net/ipv6/route.c:353
 ip6_rt_cache_alloc+0x247/0x7b0 net/ipv6/route.c:1186
 ip6_pol_route+0x8f8/0xd90 net/ipv6/route.c:1895
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2093
 fib6_rule_lookup+0x13a/0x860 net/ipv6/fib6_rules.c:118
 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2121
 ip6_route_output include/net/ip6_route.h:88 [inline]
 ip6_dst_lookup_tail+0xe27/0x1d60 net/ipv6/ip6_output.c:951
 ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1079
 rawv6_sendmsg+0x12d9/0x4630 net/ipv6/raw.c:905
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:631
 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2114
 __sys_sendmsg+0x11d/0x280 net/socket.c:2152
 __do_sys_sendmsg net/socket.c:2161 [inline]
 __se_sys_sendmsg net/socket.c:2159 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2159
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 5357:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x83/0x290 mm/slab.c:3756
 dst_destroy+0x267/0x3c0 net/core/dst.c:141
 dst_destroy_rcu+0x16/0x19 net/core/dst.c:154
 __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
 rcu_do_batch kernel/rcu/tree.c:2576 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline]
 rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864
 __do_softirq+0x30b/0xad8 kernel/softirq.c:292

The buggy address belongs to the object at ffff8801c1310bc0
 which belongs to the cache ip6_dst_cache of size 240
The buggy address is located 176 bytes inside of
 240-byte region [ffff8801c1310bc0, ffff8801c1310cb0)
The buggy address belongs to the page:
page:ffffea000704c400 count:1 mapcount:0 mapping:ffff8801cb5d21c0 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea000716c988 ffffea0007020508 ffff8801cb5d21c0
raw: 0000000000000000 ffff8801c1310080 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c1310b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff8801c1310b80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8801c1310c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8801c1310c80: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
 ffff8801c1310d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (84):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/09/11 00:37 upstream 11da3a7f84f1 f167cb6b .config console log report syz C ci-upstream-kasan-gce-root
2018/09/08 19:00 bpf-next f6f3bac08ff9 6b5120a4 .config console log report syz C ci-upstream-bpf-next-kasan-gce
2018/10/04 10:41 upstream cec4de302c5f 8b311eaf .config console log report syz ci-upstream-kasan-gce-smack-root
2018/10/04 10:40 upstream cec4de302c5f 8b311eaf .config console log report syz ci-upstream-kasan-gce-root
2018/09/28 02:15 upstream c127e59bee3e 0c2fa87b .config console log report syz ci-upstream-kasan-gce
2018/09/28 02:12 upstream c127e59bee3e 0c2fa87b .config console log report syz ci-upstream-kasan-gce-smack-root
2018/09/08 19:30 bpf 28619527b8a7 6b5120a4 .config console log report syz ci-upstream-bpf-kasan-gce
2018/10/04 10:57 linux-next 25bcda3e8b9f 8b311eaf .config console log report syz ci-upstream-linux-next-kasan-gce-root
2018/10/06 09:31 upstream 091a1eaa0e30 8b311eaf .config console log report ci-upstream-kasan-gce
2018/10/03 06:44 upstream 1d2ba7fee28b 0f3e0261 .config console log report ci-upstream-kasan-gce-selinux-root
2018/10/02 13:40 upstream 385afbf8c3e8 e06f7713 .config console log report ci-upstream-kasan-gce-root
2018/10/01 14:47 upstream 17b57b1883c1 48a50c6b .config console log report ci-upstream-kasan-gce
2018/10/01 00:12 upstream 17b57b1883c1 41e4b329 .config console log report ci-upstream-kasan-gce
2018/09/30 16:26 upstream 291d0e5d81e1 41e4b329 .config console log report ci-upstream-kasan-gce
2018/09/30 03:41 upstream 82ec752cce8b 41e4b329 .config console log report ci-upstream-kasan-gce-root
2018/09/25 11:22 upstream 2dd68cc7fd8c 0e7547d7 .config console log report ci-upstream-kasan-gce-selinux-root
2018/09/23 06:19 upstream 10dc890d4228 37079712 .config console log report ci-upstream-kasan-gce-selinux-root
2018/09/21 05:04 upstream ae596de1a0c8 6cee973c .config console log report ci-upstream-kasan-gce-root
2018/09/09 22:25 upstream 9a5682765a2e 6b5120a4 .config console log report ci-upstream-kasan-gce-smack-root
2018/09/22 17:03 upstream 10dc890d4228 37079712 .config console log report ci-upstream-kasan-gce-386
2018/09/22 10:44 upstream 10dc890d4228 37079712 .config console log report ci-upstream-kasan-gce-386
2018/10/07 22:04 bpf b799207e1e18 8b311eaf .config console log report ci-upstream-bpf-kasan-gce
2018/10/05 16:06 net-old 9d2f67e43b73 8b311eaf .config console log report ci-upstream-net-this-kasan-gce
2018/09/30 00:13 net-old 43955a45dc0b 41e4b329 .config console log report ci-upstream-net-this-kasan-gce
2018/09/26 08:12 bpf f4a518797b40 b7e11289 .config console log report ci-upstream-bpf-kasan-gce
2018/09/25 05:32 bpf fad0c40fab14 0e7547d7 .config console log report ci-upstream-bpf-kasan-gce
2018/09/24 15:00 bpf fad0c40fab14 2f485cdf .config console log report ci-upstream-bpf-kasan-gce
2018/09/22 21:24 net-old 8ac1ee6f4d62 37079712 .config console log report ci-upstream-net-this-kasan-gce
2018/09/21 06:47 bpf 080220b68714 37079712 .config console log report ci-upstream-bpf-kasan-gce
2018/10/10 02:19 bpf-next df3f94a0bbeb 8b311eaf .config console log report ci-upstream-bpf-next-kasan-gce
2018/10/08 14:07 bpf-next a2046de99193 8b311eaf .config console log report ci-upstream-bpf-next-kasan-gce
2018/10/07 19:53 bpf-next df1ea77bc51d 8b311eaf .config console log report ci-upstream-bpf-next-kasan-gce
2018/10/06 19:25 bpf-next df1ea77bc51d 8b311eaf .config console log report ci-upstream-bpf-next-kasan-gce
2018/10/04 08:44 net-next-old 7bdaae270cb5 8b311eaf .config console log report ci-upstream-net-kasan-gce
2018/10/03 19:12 bpf-next 33d9a7fd6756 8b311eaf .config console log report ci-upstream-bpf-next-kasan-gce
2018/10/03 16:05 bpf-next 33d9a7fd6756 8b311eaf .config console log report ci-upstream-bpf-next-kasan-gce
2018/10/03 14:56 bpf-next 33d9a7fd6756 8b311eaf .config console log report ci-upstream-bpf-next-kasan-gce
2018/10/02 00:16 net-next-old 3bd09b05b068 e06f7713 .config console log report ci-upstream-net-kasan-gce
2018/10/01 09:07 bpf-next 5bf7a60b8e70 48a50c6b .config console log report ci-upstream-bpf-next-kasan-gce
2018/09/30 13:47 bpf-next 5bf7a60b8e70 41e4b329 .config console log report ci-upstream-bpf-next-kasan-gce
2018/09/29 03:22 bpf-next 5bf7a60b8e70 41e4b329 .config console log report ci-upstream-bpf-next-kasan-gce
2018/09/26 11:15 bpf-next d0e13a1488ad 455b6354 .config console log report ci-upstream-bpf-next-kasan-gce
2018/09/25 20:47 net-next-old edad8d260e25 b7e11289 .config console log report ci-upstream-net-kasan-gce
2018/09/25 14:06 bpf-next 788758d1fe87 0e7547d7 .config console log report ci-upstream-bpf-next-kasan-gce
2018/09/24 11:00 net-next-old 12ba7e104552 e029c3e0 .config console log report ci-upstream-net-kasan-gce
2018/09/22 11:31 bpf-next 788758d1fe87 37079712 .config console log report ci-upstream-bpf-next-kasan-gce
2018/09/22 01:49 bpf-next 788758d1fe87 37079712 .config console log report ci-upstream-bpf-next-kasan-gce
2018/09/08 03:03 bpf-next f6f3bac08ff9 6b5120a4 .config console log report ci-upstream-bpf-next-kasan-gce
2018/09/29 09:21 linux-next 4794a36bf08d 41e4b329 .config console log report ci-upstream-linux-next-kasan-gce-root
2018/09/28 07:13 linux-next 4794a36bf08d 0c2fa87b .config console log report ci-upstream-linux-next-kasan-gce-root
2018/09/25 03:05 linux-next dad486875956 0e7547d7 .config console log report ci-upstream-linux-next-kasan-gce-root
2018/09/24 02:35 linux-next 46c163a036b4 28d9ac76 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.