In the Linux kernel, the following vulnerability has been resolved:
net/sched: flower: Fix chain template offload
When a qdisc is deleted from a net device the stack instructs the
underlying driver to remove its flow offload callback from the
associated filter block using the 'FLOW_BLOCK_UNBIND' command. The stack
then continues to replay the removal of the filters in the block for
this driver by iterating over the chains in the block and invoking the
'reoffload' operation of the classifier being used. In turn, the
classifier in its 'reoffload' operation prepares and emits a
'FLOW_CLS_DESTROY' command for each filter.
However, the stack does not do the same for chain templates and the
underlying driver never receives a 'FLOW_CLS_TMPLT_DESTROY' command when
a qdisc is deleted. This results in a memory leak [1] which can be
reproduced using [2].
Fix by introducing a 'tmplt_reoffload' operation and have the stack
invoke it with the appropriate arguments as part of the replay.
Implement the operation in the sole classifier that supports chain
templates (flower) by emitting the 'FLOW_CLS_TMPLT_{CREATE,DESTROY}'
command based on whether a flow offload callback is being bound to a
filter block or being unbound from one.
As far as I can tell, the issue happens since cited commit which
reordered tcf_block_offload_unbind() before tcf_block_flush_all_chains()
in __tcf_block_put(). The order cannot be reversed as the filter block
is expected to be freed after flushing all the chains.
[1]
unreferenced object 0xffff888107e28800 (size 2048):
comm "tc", pid 1079, jiffies 4294958525 (age 3074.287s)
hex dump (first 32 bytes):
b1 a6 7c 11 81 88 ff ff e0 5b b3 10 81 88 ff ff ..|......[......
01 00 00 00 00 00 00 00 e0 aa b0 84 ff ff ff ff ................
backtrace:
[<ffffffff81c06a68>] __kmem_cache_alloc_node+0x1e8/0x320
[<ffffffff81ab374e>] __kmalloc+0x4e/0x90
[<ffffffff832aec6d>] mlxsw_sp_acl_ruleset_get+0x34d/0x7a0
[<ffffffff832bc195>] mlxsw_sp_flower_tmplt_create+0x145/0x180
[<ffffffff832b2e1a>] mlxsw_sp_flow_block_cb+0x1ea/0x280
[<ffffffff83a10613>] tc_setup_cb_call+0x183/0x340
[<ffffffff83a9f85a>] fl_tmplt_create+0x3da/0x4c0
[<ffffffff83a22435>] tc_ctl_chain+0xa15/0x1170
[<ffffffff838a863c>] rtnetlink_rcv_msg+0x3cc/0xed0
[<ffffffff83ac87f0>] netlink_rcv_skb+0x170/0x440
[<ffffffff83ac6270>] netlink_unicast+0x540/0x820
[<ffffffff83ac6e28>] netlink_sendmsg+0x8d8/0xda0
[<ffffffff83793def>] ____sys_sendmsg+0x30f/0xa80
[<ffffffff8379d29a>] ___sys_sendmsg+0x13a/0x1e0
[<ffffffff8379d50c>] __sys_sendmsg+0x11c/0x1f0
[<ffffffff843b9ce0>] do_syscall_64+0x40/0xe0
unreferenced object 0xffff88816d2c0400 (size 1024):
comm "tc", pid 1079, jiffies 4294958525 (age 3074.287s)
hex dump (first 32 bytes):
40 00 00 00 00 00 00 00 57 f6 38 be 00 00 00 00 @.......W.8.....
10 04 2c 6d 81 88 ff ff 10 04 2c 6d 81 88 ff ff ..,m......,m....
backtrace:
[<ffffffff81c06a68>] __kmem_cache_alloc_node+0x1e8/0x320
[<ffffffff81ab36c1>] __kmalloc_node+0x51/0x90
[<ffffffff81a8ed96>] kvmalloc_node+0xa6/0x1f0
[<ffffffff82827d03>] bucket_table_alloc.isra.0+0x83/0x460
[<ffffffff82828d2b>] rhashtable_init+0x43b/0x7c0
[<ffffffff832aed48>] mlxsw_sp_acl_ruleset_get+0x428/0x7a0
[<ffffffff832bc195>] mlxsw_sp_flower_tmplt_create+0x145/0x180
[<ffffffff832b2e1a>] mlxsw_sp_flow_block_cb+0x1ea/0x280
[<ffffffff83a10613>] tc_setup_cb_call+0x183/0x340
[<ffffffff83a9f85a>] fl_tmplt_create+0x3da/0x4c0
[<ffffffff83a22435>] tc_ctl_chain+0xa15/0x1170
[<ffffffff838a863c>] rtnetlink_rcv_msg+0x3cc/0xed0
[<ffffffff83ac87f0>] netlink_rcv_skb+0x170/0x440
[<ffffffff83ac6270>] netlink_unicast+0x540/0x820
[<ffffffff83ac6e28>] netlink_sendmsg+0x8d8/0xda0
[<ffffffff83793def>] ____sys_sendmsg+0x30f/0xa80
[2]
# tc qdisc add dev swp1 clsact
# tc chain add dev swp1 ingress proto ip chain 1 flower dst_ip 0.0.0.0/32
# tc qdisc del dev
---truncated---
Metrics
Affected Vendors & Products
References
History
Wed, 13 Nov 2024 02:45:00 +0000
Type | Values Removed | Values Added |
---|---|---|
CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:9 |
Mon, 04 Nov 2024 18:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
Metrics |
ssvc
|
Thu, 08 Aug 2024 19:15:00 +0000
Type | Values Removed | Values Added |
---|---|---|
First Time appeared |
Redhat
Redhat enterprise Linux |
|
CPEs | cpe:/a:redhat:enterprise_linux:8::nfv cpe:/o:redhat:enterprise_linux:8 |
|
Vendors & Products |
Redhat
Redhat enterprise Linux |
MITRE
Status: PUBLISHED
Assigner: Linux
Published: 2024-04-02T06:43:30.378Z
Updated: 2024-11-05T09:13:33.802Z
Reserved: 2024-02-19T14:20:24.150Z
Link: CVE-2024-26669
Vulnrichment
Updated: 2024-08-02T00:14:12.714Z
NVD
Status : Awaiting Analysis
Published: 2024-04-02T07:15:43.697
Modified: 2024-11-21T09:02:48.477
Link: CVE-2024-26669
Redhat