In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: Fix out-of-bound access in fib6_add_rt2node().<\/p>\n
syzbot reported out-of-bound read in fib6_add_rt2node(). [0]<\/p>\n
When IPv6 route is created with RTA_NH_ID, struct fib6_info
\ndoes not have the trailing struct fib6_nh.<\/p>\n
The cited commit started to check !iter->fib6_nh->fib_nh_gw_family
\nto ensure that rt6_qualify_for_ecmp() will return false for iter.<\/p>\n
If iter->nh is not NULL, rt6_qualify_for_ecmp() returns false anyway.<\/p>\n
Let’s check iter->nh before reading iter->fib6_nh and avoid OOB read.<\/p>\n
[0]:
\nBUG: KASAN: slab-out-of-bounds in fib6_add_rt2node+0x349c\/0x3500 net\/ipv6\/ip6_fib.c:1142
\nRead of size 1 at addr ffff8880384ba6de by task syz.0.18\/5500<\/p>\n
CPU: 0 UID: 0 PID: 5500 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full)
\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04\/01\/2014
\nCall Trace:<\/p>\n
dump_stack_lvl+0xe8\/0x150 lib\/dump_stack.c:120
\n print_address_description mm\/kasan\/report.c:378 [inline]
\n print_report+0xba\/0x230 mm\/kasan\/report.c:482
\n kasan_report+0x117\/0x150 mm\/kasan\/report.c:595
\n fib6_add_rt2node+0x349c\/0x3500 net\/ipv6\/ip6_fib.c:1142
\n fib6_add_rt2node_nh net\/ipv6\/ip6_fib.c:1363 [inline]
\n fib6_add+0x910\/0x18c0 net\/ipv6\/ip6_fib.c:1531
\n __ip6_ins_rt net\/ipv6\/route.c:1351 [inline]
\n ip6_route_add+0xde\/0x1b0 net\/ipv6\/route.c:3957
\n inet6_rtm_newroute+0x268\/0x19e0 net\/ipv6\/route.c:5660
\n rtnetlink_rcv_msg+0x7d5\/0xbe0 net\/core\/rtnetlink.c:6958
\n netlink_rcv_skb+0x232\/0x4b0 net\/netlink\/af_netlink.c:2550
\n netlink_unicast_kernel net\/netlink\/af_netlink.c:1318 [inline]
\n netlink_unicast+0x80f\/0x9b0 net\/netlink\/af_netlink.c:1344
\n netlink_sendmsg+0x813\/0xb40 net\/netlink\/af_netlink.c:1894
\n sock_sendmsg_nosec net\/socket.c:727 [inline]
\n __sock_sendmsg net\/socket.c:742 [inline]
\n ____sys_sendmsg+0xa68\/0xad0 net\/socket.c:2592
\n ___sys_sendmsg+0x2a5\/0x360 net\/socket.c:2646
\n __sys_sendmsg net\/socket.c:2678 [inline]
\n __do_sys_sendmsg net\/socket.c:2683 [inline]
\n __se_sys_sendmsg net\/socket.c:2681 [inline]
\n __x64_sys_sendmsg+0x1bd\/0x2a0 net\/socket.c:2681
\n do_syscall_x64 arch\/x86\/entry\/syscall_64.c:63 [inline]
\n do_syscall_64+0xe2\/0xf80 arch\/x86\/entry\/syscall_64.c:94
\n entry_SYSCALL_64_after_hwframe+0x77\/0x7f
\nRIP: 0033:0x7f9316b9aeb9
\nCode: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
\nRSP: 002b:00007ffd8809b678 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
\nRAX: ffffffffffffffda RBX: 00007f9316e15fa0 RCX: 00007f9316b9aeb9
\nRDX: 0000000000000000 RSI: 0000200000004380 RDI: 0000000000000003
\nRBP: 00007f9316c08c1f R08: 0000000000000000 R09: 0000000000000000
\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
\nR13: 00007f9316e15fac R14: 00007f9316e15fa0 R15: 00007f9316e15fa0<\/p>\n
Allocated by task 5499:
\n kasan_save_stack mm\/kasan\/common.c:57 [inline]
\n kasan_save_track+0x3e\/0x80 mm\/kasan\/common.c:78
\n poison_kmalloc_redzone mm\/kasan\/common.c:398 [inline]
\n __kasan_kmalloc+0x93\/0xb0 mm\/kasan\/common.c:415
\n kasan_kmalloc include\/linux\/kasan.h:263 [inline]
\n __do_kmalloc_node mm\/slub.c:5657 [inline]
\n __kmalloc_noprof+0x40c\/0x7e0 mm\/slub.c:5669
\n kmalloc_noprof include\/linux\/slab.h:961 [inline]
\n kzalloc_noprof include\/linux\/slab.h:1094 [inline]
\n fib6_info_alloc+0x30\/0xf0 net\/ipv6\/ip6_fib.c:155
\n ip6_route_info_create+0x142\/0x860 net\/ipv6\/route.c:3820
\n ip6_route_add+0x49\/0x1b0 net\/ipv6\/route.c:3949
\n inet6_rtm_newroute+0x268\/0x19e0 net\/ipv6\/route.c:5660
\n rtnetlink_rcv_msg+0x7d5\/0xbe0 net\/core\/rtnetlink.c:6958
\n netlink_rcv_skb+0x232\/0x4b0 net\/netlink\/af_netlink.c:2550
\n netlink_unicast_kernel net\/netlink\/af_netlink.c:1318 [inline]
\n netlink_unicast+0x80f\/0x9b0 net\/netlink\/af_netlink.c:1344
\n netlink_sendmsg+0x813\/0xb40 net\/netlink\/af_netlink.c:1894
\n sock_sendmsg_nosec net\/socket.c:727 [inline]
\n __sock_sendmsg net\/socket.c:742 [inline]
\n ____sys_sendmsg+0xa68\/0xad0 net\/socket.c:2592
\n ___sys_s
\n—truncated—<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: Fix out-of-bound access in fib6_add_rt2node().<\/p>\n
syzbot reported out-of-bound read in fib6_add_rt2node(). [0]<\/p>\n
When IPv6 route<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-15471","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/15471","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15471"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15471"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15471"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}