| Message ID | 20190405073153.22320-2-andrea.righi@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [SRU,X/B/C/D,v2,1/1] openvswitch: fix flow actions reallocation | expand |
On Fri, 5 Apr 2019 09:31:53 +0200 Andrea Righi <andrea.righi@canonical.com> wrote: > BugLink: https://bugs.launchpad.net/bugs/1813244 > > 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> > (cherry picked from commit f28cd2af22a0c134e4aa1c64a70f70d815d473fb) > Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Clean cherry pick from upstream and indeed seems to fix LP: #1736390. Very nice! Acked-by: Juerg Haefliger <juergh@canonical.com> > --- > net/openvswitch/flow_netlink.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c > index 691da853bef5..4bdf5e3ac208 100644 > --- a/net/openvswitch/flow_netlink.c > +++ b/net/openvswitch/flow_netlink.c > @@ -2306,14 +2306,14 @@ 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) {
Resending with ACK in the email subject :-/ > On Fri, 5 Apr 2019 09:31:53 +0200 > Andrea Righi <andrea.righi@canonical.com> wrote: > > > BugLink: https://bugs.launchpad.net/bugs/1813244 > > > > 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> > > (cherry picked from commit f28cd2af22a0c134e4aa1c64a70f70d815d473fb) > > Signed-off-by: Andrea Righi <andrea.righi@canonical.com> > > Clean cherry pick from upstream and indeed seems to fix LP: #1736390. Very nice! > > Acked-by: Juerg Haefliger <juergh@canonical.com> > > > > --- > > net/openvswitch/flow_netlink.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c > > index 691da853bef5..4bdf5e3ac208 100644 > > --- a/net/openvswitch/flow_netlink.c > > +++ b/net/openvswitch/flow_netlink.c > > @@ -2306,14 +2306,14 @@ 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) { >
On 05/04/2019 08:31, Andrea Righi wrote: > BugLink: https://bugs.launchpad.net/bugs/1813244 > > 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> > (cherry picked from commit f28cd2af22a0c134e4aa1c64a70f70d815d473fb) > Signed-off-by: Andrea Righi <andrea.righi@canonical.com> > --- > net/openvswitch/flow_netlink.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c > index 691da853bef5..4bdf5e3ac208 100644 > --- a/net/openvswitch/flow_netlink.c > +++ b/net/openvswitch/flow_netlink.c > @@ -2306,14 +2306,14 @@ 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) { > Clean cherry pick. Thanks! Acked-by: Colin Ian King <colin.king@canonical.com>
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c index 691da853bef5..4bdf5e3ac208 100644 --- a/net/openvswitch/flow_netlink.c +++ b/net/openvswitch/flow_netlink.c @@ -2306,14 +2306,14 @@ 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) {