Paolo Valerio 24f0f311a0 openvswitch: fix OOB access in reserve_sfa_size() ... commit cefa91b233 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-04-27 14:41:14 +02:00
..
actions.c	net: openvswitch: don't send internal clone attribute to the userspace.	2022-04-13 19:27:32 +02:00
conntrack.c	openvswitch: always update flow key after nat	2022-04-08 13:58:22 +02:00
conntrack.h
datapath.c
datapath.h
dp_notify.c
flow.c	net: openvswitch: Fix ct_state nat flags for conns arriving from tc	2022-01-09 16:24:12 -08:00
flow.h
flow_netlink.c	openvswitch: fix OOB access in reserve_sfa_size()	2022-04-27 14:41:14 +02:00
flow_netlink.h
flow_table.c
flow_table.h
Kconfig
Makefile
meter.c
meter.h
openvswitch_trace.c
openvswitch_trace.h
vport-geneve.c
vport-gre.c
vport-internal_dev.c
vport-internal_dev.h
vport-netdev.c
vport-netdev.h
vport-vxlan.c
vport.c
vport.h