* [PATCH] openvswitch: fix OOB access in reserve_sfa_size()
@ 2022-09-01 0:56 chen zhang
0 siblings, 0 replies; 4+ messages in thread
From: chen zhang @ 2022-09-01 0:56 UTC (permalink / raw)
To: chenzhang
Cc: chenzhang_0901, Paolo Valerio, stable, Eelco Chaudron, David S . Miller
From: Paolo Valerio <pvalerio@redhat.com>
Mainline: cefa91b2332d7009bc0be5d951d6cbbf349f90f8
From: v5.18-rc4
Severity: Low
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: f28cd2af22a0 ("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: chen zhang <chenzhang@kylinos.cn>
Change-Id: Ida20ea8a448b3641df21661983a0b730c3c12e14
---
net/openvswitch/flow_netlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index c591b923016a..d77c21ff066c 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -2436,7 +2436,7 @@ static struct nlattr *reserve_sfa_size(struct sw_flow_actions **sfa,
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) {
+ if ((next_offset + req_size) > MAX_ACTIONS_BUFSIZE) {
OVS_NLERR(log, "Flow action size exceeds max %u",
MAX_ACTIONS_BUFSIZE);
return ERR_PTR(-EMSGSIZE);
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] openvswitch: fix OOB access in reserve_sfa_size()
@ 2022-08-31 5:52 chen zhang
0 siblings, 0 replies; 4+ messages in thread
From: chen zhang @ 2022-08-31 5:52 UTC (permalink / raw)
To: chenzhang; +Cc: Paolo Valerio, stable, Eelco Chaudron, David S . Miller
From: Paolo Valerio <pvalerio@redhat.com>
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: f28cd2af22a0 ("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>
---
net/openvswitch/flow_netlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 7176156d3844..4c09cf8a0ab2 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -2465,7 +2465,7 @@ static struct nlattr *reserve_sfa_size(struct sw_flow_actions **sfa,
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) {
+ if ((next_offset + req_size) > MAX_ACTIONS_BUFSIZE) {
OVS_NLERR(log, "Flow action size exceeds max %u",
MAX_ACTIONS_BUFSIZE);
return ERR_PTR(-EMSGSIZE);
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] openvswitch: fix OOB access in reserve_sfa_size()
2022-04-15 8:08 Paolo Valerio
@ 2022-04-15 11:00 ` patchwork-bot+netdevbpf
0 siblings, 0 replies; 4+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-04-15 11:00 UTC (permalink / raw)
To: Paolo Valerio; +Cc: netdev, dev, pshelar, davem, kuba, pabeni, stable
Hello:
This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:
On Fri, 15 Apr 2022 10:08:41 +0200 you wrote:
> 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.
>
> [...]
Here is the summary with links:
- openvswitch: fix OOB access in reserve_sfa_size()
https://git.kernel.org/netdev/net/c/cefa91b2332d
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] openvswitch: fix OOB access in reserve_sfa_size()
@ 2022-04-15 8:08 Paolo Valerio
2022-04-15 11:00 ` patchwork-bot+netdevbpf
0 siblings, 1 reply; 4+ messages in thread
From: Paolo Valerio @ 2022-04-15 8:08 UTC (permalink / raw)
To: netdev, dev
Cc: Pravin B Shelar, David S. Miller, Jakub Kicinski, Paolo Abeni, stable
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: f28cd2af22a0 ("openvswitch: fix flow actions reallocation")
Signed-off-by: Paolo Valerio <pvalerio@redhat.com>
---
net/openvswitch/flow_netlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 7176156d3844..4c09cf8a0ab2 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -2465,7 +2465,7 @@ static struct nlattr *reserve_sfa_size(struct sw_flow_actions **sfa,
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) {
+ if ((next_offset + req_size) > MAX_ACTIONS_BUFSIZE) {
OVS_NLERR(log, "Flow action size exceeds max %u",
MAX_ACTIONS_BUFSIZE);
return ERR_PTR(-EMSGSIZE);
^ permalink raw reply related [flat|nested] 4+ messages in thread
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Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2022-09-01 0:56 [PATCH] openvswitch: fix OOB access in reserve_sfa_size() chen zhang
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2022-04-15 8:08 Paolo Valerio
2022-04-15 11:00 ` patchwork-bot+netdevbpf
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