[ Upstream commit dfe28c4167a9259fc0c372d9f9473e1ac95cff67 ]
The validation of the set(nsh(...)) action is completely wrong.
It runs through the nsh_key_put_from_nlattr() function that is the
same function that validates NSH keys for the flow match and the
push_nsh() action. However, the set(nsh(...)) has a very different
memory layout. Nested attributes in there are doubled in size in
case of the masked set(). That makes proper validation impossible.
There is also confusion in the code between the 'masked' flag, that
says that the nested attributes are doubled in size containing both
the value and the mask, and the 'is_mask' that says that the value
we're parsing is the mask. This is causing kernel crash on trying to
write into mask part of the match with SW_FLOW_KEY_PUT() during
validation, while validate_nsh() doesn't allocate any memory for it:
BUG: kernel NULL pointer dereference, address: 0000000000000018
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 1c2383067 P4D 1c2383067 PUD 20b703067 PMD 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 8 UID: 0 Kdump: loaded Not tainted 6.17.0-rc4+ #107 PREEMPT(voluntary)
RIP: 0010:nsh_key_put_from_nlattr+0x19d/0x610 [openvswitch]
Call Trace:
<TASK>
validate_nsh+0x60/0x90 [openvswitch]
validate_set.constprop.0+0x270/0x3c0 [openvswitch]
__ovs_nla_copy_actions+0x477/0x860 [openvswitch]
ovs_nla_copy_actions+0x8d/0x100 [openvswitch]
ovs_packet_cmd_execute+0x1cc/0x310 [openvswitch]
genl_family_rcv_msg_doit+0xdb/0x130
genl_family_rcv_msg+0x14b/0x220
genl_rcv_msg+0x47/0xa0
netlink_rcv_skb+0x53/0x100
genl_rcv+0x24/0x40
netlink_unicast+0x280/0x3b0
netlink_sendmsg+0x1f7/0x430
____sys_sendmsg+0x36b/0x3a0
___sys_sendmsg+0x87/0xd0
__sys_sendmsg+0x6d/0xd0
do_syscall_64+0x7b/0x2c0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The third issue with this process is that while trying to convert
the non-masked set into masked one, validate_set() copies and doubles
the size of the OVS_KEY_ATTR_NSH as if it didn't have any nested
attributes. It should be copying each nested attribute and doubling
them in size independently. And the process must be properly reversed
during the conversion back from masked to a non-masked variant during
the flow dump.
In the end, the only two outcomes of trying to use this action are
either validation failure or a kernel crash. And if somehow someone
manages to install a flow with such an action, it will most definitely
not do what it is supposed to, since all the keys and the masks are
mixed up.
Fixing all the issues is a complex task as it requires re-writing
most of the validation code.
Given that and the fact that this functionality never worked since
introduction, let's just remove it altogether. It's better to
re-introduce it later with a proper implementation instead of trying
to fix it in stable releases.
Fixes: b2d0f5d5dc53 ("openvswitch: enable NSH support")
Reported-by: Junvy Yang <zhuque@tencent.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20251112112246.95064-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 65d91192aa66f05710cfddf6a14b5a25ee554dba ]
It's not safe to access nla_len(ovs_key) if the data is smaller than
the netlink header. Check that the attribute is OK first.
Fixes: ccb1352e76cf ("net: Add Open vSwitch kernel components.")
Reported-by: syzbot+b07a9da40df1576b8048@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b07a9da40df1576b8048
Tested-by: syzbot+b07a9da40df1576b8048@syzkaller.appspotmail.com
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20250412104052.2073688-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1f30fb9166d4f15a1aa19449b9da871fe0ed4796 upstream.
While parsing user-provided actions, openvswitch module may dynamically
allocate memory and store pointers in the internal copy of the actions.
So this memory has to be freed while destroying the actions.
Currently there are only two such actions: ct() and set(). However,
there are many actions that can hold nested lists of actions and
ovs_nla_free_flow_actions() just jumps over them leaking the memory.
For example, removal of the flow with the following actions will lead
to a leak of the memory allocated by nf_ct_tmpl_alloc():
actions:clone(ct(commit),0)
Non-freed set() action may also leak the 'dst' structure for the
tunnel info including device references.
Under certain conditions with a high rate of flow rotation that may
cause significant memory leak problem (2MB per second in reporter's
case). The problem is also hard to mitigate, because the user doesn't
have direct control over the datapath flows generated by OVS.
Fix that by iterating over all the nested actions and freeing
everything that needs to be freed recursively.
New build time assertion should protect us from this problem if new
actions will be added in the future.
Unfortunately, openvswitch module doesn't use NLA_F_NESTED, so all
attributes has to be explicitly checked. sample() and clone() actions
are mixing extra attributes into the user-provided action list. That
prevents some code generalization too.
Fixes: 34ae932a4036 ("openvswitch: Make tunnel set action attach a metadata dst")
Link: https://mail.openvswitch.org/pipermail/ovs-dev/2022-March/392922.html
Reported-by: Stéphane Graber <stgraber@ubuntu.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[Backport for 5.4: Removed handling of OVS_ACTION_ATTR_DEC_TTL as it
doesn't exist in this version. BUILD_BUG_ON condition adjusted
accordingly.]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cefa91b2332d7009bc0be5d951d6cbbf349f90f8 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: 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3f2a3050b4a3e7f32fc0ea3c9b0183090ae00522 ]
'OVS_CLONE_ATTR_EXEC' is an internal attribute that is used for
performance optimization inside the kernel. It's added by the kernel
while parsing user-provided actions and should not be sent during the
flow dump as it's not part of the uAPI.
The issue doesn't cause any significant problems to the ovs-vswitchd
process, because reported actions are not really used in the
application lifecycle and only supposed to be shown to a human via
ovs-dpctl flow dump. However, the action list is still incorrect
and causes the following error if the user wants to look at the
datapath flows:
# ovs-dpctl add-dp system@ovs-system
# ovs-dpctl add-flow "<flow match>" "clone(ct(commit),0)"
# ovs-dpctl dump-flows
<flow match>, packets:0, bytes:0, used:never,
actions:clone(bad length 4, expected -1 for: action0(01 00 00 00),
ct(commit),0)
With the fix:
# ovs-dpctl dump-flows
<flow match>, packets:0, bytes:0, used:never,
actions:clone(ct(commit),0)
Additionally fixed an incorrect attribute name in the comment.
Fixes: b233504033db ("openvswitch: kernel datapath clone action")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/20220404104150.2865736-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f19c44452b58a84d95e209b847f5495d91c9983a upstream. IPv6 nd target mask was not getting populated in flow dump. In the function __ovs_nla_put_key the icmp code mask field was checked instead of icmp code key field to classify the flow as neighbour discovery. ufid:bdfbe3e5-60c2-43b0-a5ff-dfcac1c37328, recirc_id(0),dp_hash(0/0), skb_priority(0/0),in_port(ovs-nm1),skb_mark(0/0),ct_state(0/0), ct_zone(0/0),ct_mark(0/0),ct_label(0/0), eth(src=00:00:00:00:00:00/00:00:00:00:00:00, dst=00:00:00:00:00:00/00:00:00:00:00:00), eth_type(0x86dd), ipv6(src=::/::,dst=::/::,label=0/0,proto=58,tclass=0/0,hlimit=0/0,frag=no), icmpv6(type=135,code=0), nd(target=2001::2/::, sll=00:00:00:00:00:00/00:00:00:00:00:00, tll=00:00:00:00:00:00/00:00:00:00:00:00), packets:10, bytes:860, used:0.504s, dp:ovs, actions:ovs-nm2 Fixes: e64457191a25 (openvswitch: Restructure datapath.c and flow.c) Signed-off-by: Martin Varghese <martin.varghese@nokia.com> Link: https://lore.kernel.org/r/20220328054148.3057-1-martinvarghesenokia@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin street fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 21 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141334.228102212@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We currently have two levels of strict validation:
1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size
The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().
Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.
We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated
Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)
@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)
@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)
For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.
Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.
Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.
In effect then, this adds fully strict validation for any new command.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Minor comment merge conflict in mlx5. Staging driver has a fixup due to the skb->xmit_more changes in 'net-next', but was removed in 'net'. Signed-off-by: David S. Miller <davem@davemloft.net>