linux/net/openvswitch
Paolo Valerio cefa91b233 openvswitch: fix OOB access in reserve_sfa_size()
Given a sufficiently large number of actions, while copying and
reserving memory for a new action of a new flow, if next_offset is
greater than MAX_ACTIONS_BUFSIZE, the function reserve_sfa_size() does
not return -EMSGSIZE as expected, but it allocates MAX_ACTIONS_BUFSIZE
bytes increasing actions_len by req_size. This can then lead to an OOB
write access, especially when further actions need to be copied.

Fix it by rearranging the flow action size check.

KASAN splat below:

==================================================================
BUG: KASAN: slab-out-of-bounds in reserve_sfa_size+0x1ba/0x380 [openvswitch]
Write of size 65360 at addr ffff888147e4001c by task handler15/836

CPU: 1 PID: 836 Comm: handler15 Not tainted 5.18.0-rc1+ #27
...
Call Trace:
 <TASK>
 dump_stack_lvl+0x45/0x5a
 print_report.cold+0x5e/0x5db
 ? __lock_text_start+0x8/0x8
 ? reserve_sfa_size+0x1ba/0x380 [openvswitch]
 kasan_report+0xb5/0x130
 ? reserve_sfa_size+0x1ba/0x380 [openvswitch]
 kasan_check_range+0xf5/0x1d0
 memcpy+0x39/0x60
 reserve_sfa_size+0x1ba/0x380 [openvswitch]
 __add_action+0x24/0x120 [openvswitch]
 ovs_nla_add_action+0xe/0x20 [openvswitch]
 ovs_ct_copy_action+0x29d/0x1130 [openvswitch]
 ? __kernel_text_address+0xe/0x30
 ? unwind_get_return_address+0x56/0xa0
 ? create_prof_cpu_mask+0x20/0x20
 ? ovs_ct_verify+0xf0/0xf0 [openvswitch]
 ? prep_compound_page+0x198/0x2a0
 ? __kasan_check_byte+0x10/0x40
 ? kasan_unpoison+0x40/0x70
 ? ksize+0x44/0x60
 ? reserve_sfa_size+0x75/0x380 [openvswitch]
 __ovs_nla_copy_actions+0xc26/0x2070 [openvswitch]
 ? __zone_watermark_ok+0x420/0x420
 ? validate_set.constprop.0+0xc90/0xc90 [openvswitch]
 ? __alloc_pages+0x1a9/0x3e0
 ? __alloc_pages_slowpath.constprop.0+0x1da0/0x1da0
 ? unwind_next_frame+0x991/0x1e40
 ? __mod_node_page_state+0x99/0x120
 ? __mod_lruvec_page_state+0x2e3/0x470
 ? __kasan_kmalloc_large+0x90/0xe0
 ovs_nla_copy_actions+0x1b4/0x2c0 [openvswitch]
 ovs_flow_cmd_new+0x3cd/0xb10 [openvswitch]
 ...

Cc: stable@vger.kernel.org
Fixes: f28cd2af22 ("openvswitch: fix flow actions reallocation")
Signed-off-by: Paolo Valerio <pvalerio@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-15 11:50:02 +01:00
..
actions.c net: openvswitch: don't send internal clone attribute to the userspace. 2022-04-05 17:57:54 -07:00
conntrack.c openvswitch: always update flow key after nat 2022-03-21 22:29:10 -07:00
conntrack.h net/sched: act_api: fix miss set post_ct for ovs after do conntrack in act_ct 2021-03-16 15:22:18 -07:00
datapath.c net/sched: Enable tc skb ext allocation on chain miss only when needed 2022-02-05 10:12:53 +00:00
datapath.h net/sched: Enable tc skb ext allocation on chain miss only when needed 2022-02-05 10:12:53 +00:00
dp_notify.c net: openvswitch: use netif_ovs_is_port() instead of opencode 2019-07-08 15:53:25 -07:00
flow_netlink.c openvswitch: fix OOB access in reserve_sfa_size() 2022-04-15 11:50:02 +01:00
flow_netlink.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269 2019-06-05 17:30:29 +02:00
flow_table.c openvswitch: Optimize operation for key comparison 2021-07-01 11:13:10 -07:00
flow_table.h net: openvswitch: fix to make sure flow_lookup() is not preempted 2020-10-18 12:29:36 -07:00
flow.c net: openvswitch: remove unneeded semicolon 2022-03-02 22:22:18 -08:00
flow.h net: openvswitch: IPv6: Add IPv6 extension header support 2022-02-25 10:32:55 +00:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile openvswitch: add trace points 2021-06-22 10:47:32 -07:00
meter.c include/linux/mm.h: move nr_free_buffer_pages from swap.h to mm.h 2021-11-06 13:30:43 -07:00
meter.h net: openvswitch: use u64 for meter bucket 2020-04-23 18:26:11 -07:00
openvswitch_trace.c openvswitch: add trace points 2021-06-22 10:47:32 -07:00
openvswitch_trace.h openvswitch: add trace points 2021-06-22 10:47:32 -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 core API to update/provide stats 2020-11-14 16:59:32 -08:00
vport-internal_dev.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269 2019-06-05 17:30:29 +02:00
vport-netdev.c openvswitch: add net device refcount tracker to struct vport 2021-12-07 20:45:00 -08:00
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: Add skb_clear_tstamp() to keep the mono delivery_time 2022-03-03 14:38:48 +00:00
vport.h openvswitch: add net device refcount tracker to struct vport 2021-12-07 20:45:00 -08:00