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authorAndrea Righi <andrea.righi@canonical.com>2019-04-10 15:50:22 -0700
committerBen Pfaff <blp@ovn.org>2019-04-15 09:32:14 -0700
commitd4f26c39eb1cb422b476a5a699b5f376cc0c40b9 (patch)
treed5f53516b4b519712c7cfd14542a6503e5685221
parent371468b00184408dea235b5a50da2984bb654a8f (diff)
downloadopenvswitch-d4f26c39eb1cb422b476a5a699b5f376cc0c40b9.tar.gz
datapath: fix flow actions reallocation
Upstream commit: commit f28cd2af22a0c134e4aa1c64a70f70d815d473fb Author: Andrea Righi <andrea.righi@canonical.com> Date: Thu Mar 28 07:36:00 2019 +0100 openvswitch: fix flow actions reallocation The flow action buffer can be resized if it's not big enough to contain all the requested flow actions. However, this resize doesn't take into account the new requested size, the buffer is only increased by a factor of 2x. This might be not enough to contain the new data, causing a buffer overflow, for example: [ 42.044472] ============================================================================= [ 42.045608] BUG kmalloc-96 (Not tainted): Redzone overwritten [ 42.046415] ----------------------------------------------------------------------------- [ 42.047715] Disabling lock debugging due to kernel taint [ 42.047716] INFO: 0x8bf2c4a5-0x720c0928. First byte 0x0 instead of 0xcc [ 42.048677] INFO: Slab 0xbc6d2040 objects=29 used=18 fp=0xdc07dec4 flags=0x2808101 [ 42.049743] INFO: Object 0xd53a3464 @offset=2528 fp=0xccdcdebb [ 42.050747] Redzone 76f1b237: cc cc cc cc cc cc cc cc ........ [ 42.051839] Object d53a3464: 6b 6b 6b 6b 6b 6b 6b 6b 0c 00 00 00 6c 00 00 00 kkkkkkkk....l... [ 42.053015] Object f49a30cc: 6c 00 0c 00 00 00 00 00 00 00 00 03 78 a3 15 f6 l...........x... [ 42.054203] Object acfe4220: 20 00 02 00 ff ff ff ff 00 00 00 00 00 00 00 00 ............... [ 42.055370] Object 21024e91: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.056541] Object 070e04c3: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.057797] Object 948a777a: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.059061] Redzone 8bf2c4a5: 00 00 00 00 .... [ 42.060189] Padding a681b46e: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ Fix by making sure the new buffer is properly resized to contain all the requested data. BugLink: https://bugs.launchpad.net/bugs/1813244 Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Andrea Righi <andrea.righi@canonical.com> Acked-by: William Tu <u9012063@gmail.com> Signed-off-by: Greg Rose <gvrose8192@gmail.com> Signed-off-by: Ben Pfaff <blp@ovn.org>
-rw-r--r--datapath/flow_netlink.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/datapath/flow_netlink.c b/datapath/flow_netlink.c
index aa68dba98..9e1aa5b4e 100644
--- a/datapath/flow_netlink.c
+++ b/datapath/flow_netlink.c
@@ -1746,14 +1746,14 @@ static struct nlattr *reserve_sfa_size(struct sw_flow_actions **sfa,
struct sw_flow_actions *acts;
int new_acts_size;
- int req_size = NLA_ALIGN(attr_len);
+ size_t req_size = NLA_ALIGN(attr_len);
int next_offset = offsetof(struct sw_flow_actions, actions) +
(*sfa)->actions_len;
if (req_size <= (ksize(*sfa) - next_offset))
goto out;
- new_acts_size = ksize(*sfa) * 2;
+ new_acts_size = max(next_offset + req_size, ksize(*sfa) * 2);
if (new_acts_size > MAX_ACTIONS_BUFSIZE) {
if ((MAX_ACTIONS_BUFSIZE - next_offset) < req_size)