Davide Caratti a1478374b0 openvswitch: fix stack OOB read while fragmenting IPv4 packets ... commit 7c0ea5930c upstream. running openvswitch on kernels built with KASAN, it's possible to see the following splat while testing fragmentation of IPv4 packets: BUG: KASAN: stack-out-of-bounds in ip_do_fragment+0x1b03/0x1f60 Read of size 1 at addr ffff888112fc713c by task handler2/1367 CPU: 0 PID: 1367 Comm: handler2 Not tainted 5.12.0-rc6+ #418 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014 Call Trace: dump_stack+0x92/0xc1 print_address_description.constprop.7+0x1a/0x150 kasan_report.cold.13+0x7f/0x111 ip_do_fragment+0x1b03/0x1f60 ovs_fragment+0x5bf/0x840 [openvswitch] do_execute_actions+0x1bd5/0x2400 [openvswitch] ovs_execute_actions+0xc8/0x3d0 [openvswitch] ovs_packet_cmd_execute+0xa39/0x1150 [openvswitch] genl_family_rcv_msg_doit.isra.15+0x227/0x2d0 genl_rcv_msg+0x287/0x490 netlink_rcv_skb+0x120/0x380 genl_rcv+0x24/0x40 netlink_unicast+0x439/0x630 netlink_sendmsg+0x719/0xbf0 sock_sendmsg+0xe2/0x110 ____sys_sendmsg+0x5ba/0x890 ___sys_sendmsg+0xe9/0x160 __sys_sendmsg+0xd3/0x170 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f957079db07 Code: c3 66 90 41 54 41 89 d4 55 48 89 f5 53 89 fb 48 83 ec 10 e8 eb ec ff ff 44 89 e2 48 89 ee 89 df 41 89 c0 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 48 89 44 24 08 e8 24 ed ff ff 48 RSP: 002b:00007f956ce35a50 EFLAGS: 00000293 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000019 RCX: 00007f957079db07 RDX: 0000000000000000 RSI: 00007f956ce35ae0 RDI: 0000000000000019 RBP: 00007f956ce35ae0 R08: 0000000000000000 R09: 00007f9558006730 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f956ce37308 R14: 00007f956ce35f80 R15: 00007f956ce35ae0 The buggy address belongs to the page: page:00000000af2a1d93 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x112fc7 flags: 0x17ffffc0000000() raw: 0017ffffc0000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected addr ffff888112fc713c is located in stack of task handler2/1367 at offset 180 in frame: ovs_fragment+0x0/0x840 [openvswitch] this frame has 2 objects: [32, 144) 'ovs_dst' [192, 424) 'ovs_rt' Memory state around the buggy address: ffff888112fc7000: f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888112fc7080: 00 f1 f1 f1 f1 00 00 00 00 00 00 00 00 00 00 00 >ffff888112fc7100: 00 00 00 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 ^ ffff888112fc7180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888112fc7200: 00 00 00 00 00 00 f2 f2 f2 00 00 00 00 00 00 00 for IPv4 packets, ovs_fragment() uses a temporary struct dst_entry. Then, in the following call graph: ip_do_fragment() ip_skb_dst_mtu() ip_dst_mtu_maybe_forward() ip_mtu_locked() the pointer to struct dst_entry is used as pointer to struct rtable: this turns the access to struct members like rt_mtu_locked into an OOB read in the stack. Fix this changing the temporary variable used for IPv4 packets in ovs_fragment(), similarly to what is done for IPv6 few lines below. Fixes: d52e5a7e7c ("ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmt") Cc: <stable@vger.kernel.org> Acked-by: Eelco Chaudron <echaudro@redhat.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-05-11 14:47:34 +02:00
..
actions.c	openvswitch: fix stack OOB read while fragmenting IPv4 packets	2021-05-11 14:47:34 +02:00
conntrack.c	openvswitch: fix send of uninitialized stack memory in ct limit reply	2021-04-14 08:42:10 +02:00
conntrack.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295	2019-06-05 17:36:38 +02:00
datapath.c	net: openvswitch: silence suspicious RCU usage warning	2020-11-03 16:57:42 -08:00
datapath.h	net: openvswitch: add masks cache hit counter	2020-08-03 15:17:48 -07:00
dp_notify.c	net: openvswitch: use netif_ovs_is_port() instead of opencode	2019-07-08 15:53:25 -07:00
flow.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
flow.h	treewide: Use sizeof_field() macro	2019-12-09 10:36:44 -08:00
flow_netlink.c	openvswitch: fix error return code in validate_and_copy_dec_ttl()	2020-12-04 15:43:14 -08:00
flow_netlink.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269	2019-06-05 17:30:29 +02:00
flow_table.c	net: openvswitch: silence suspicious RCU usage warning	2020-11-03 16:57:42 -08:00
flow_table.h	net: openvswitch: fix to make sure flow_lookup() is not preempted	2020-10-18 12:29:36 -07:00
Kconfig	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
Makefile	openvswitch: Add meter infrastructure	2017-11-13 10:37:07 +09:00
meter.c	net: openvswitch: Constify static struct genl_small_ops	2020-10-04 21:13:36 -07:00
meter.h	net: openvswitch: use u64 for meter bucket	2020-04-23 18:26:11 -07:00
vport-geneve.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
vport-gre.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269	2019-06-05 17:30:29 +02:00
vport-internal_dev.c	net: openvswitch: use new function dev_fetch_sw_netstats	2020-10-13 17:33:49 -07:00
vport-internal_dev.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269	2019-06-05 17:30:29 +02:00
vport-netdev.c	net: openvswitch: use netif_ovs_is_port() instead of opencode	2019-07-08 15:53:25 -07:00
vport-netdev.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269	2019-06-05 17:30:29 +02:00
vport-vxlan.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269	2019-06-05 17:30:29 +02:00
vport.c	net: openvswitch: improve the coding style	2020-09-01 11:42:15 -07:00
vport.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269	2019-06-05 17:30:29 +02:00