title: team: fix null-ptr-deref when team device type is changed
description: In the Linux kernel, the following vulnerability has been resolved:
team: fix null-ptr-deref when team device type is changed
Get a null-ptr-deref bug as follows with reproducer [1].
BUG: kernel NULL pointer dereference, address: 0000000000000228
...
RIP: 0010:vlan_dev_hard_header+0x35/0x140 [8021q]
...
Call Trace:
<TASK>
? __die+0x24/0x70
? page_fault_oops+0x82/0x150
? exc_page_fault+0x69/0x150
? asm_exc_page_fault+0x26/0x30
? vlan_dev_hard_header+0x35/0x140 [8021q]
? vlan_dev_hard_header+0x8e/0x140 [8021q]
neigh_connected_output+0xb2/0x100
ip6_finish_output2+0x1cb/0x520
? nf_hook_slow+0x43/0xc0
? ip6_mtu+0x46/0x80
ip6_finish_output+0x2a/0xb0
mld_sendpack+0x18f/0x250
mld_ifc_work+0x39/0x160
process_one_work+0x1e6/0x3f0
worker_thread+0x4d/0x2f0
? __pfx_worker_thread+0x10/0x10
kthread+0xe5/0x120
? __pfx_kthread+0x10/0x10
ret_from_fork+0x34/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
[1]
$ teamd -t team0 -d -c '{"runner": {"name": "loadbalance"}}'
$ ip link add name t-dummy type dummy
$ ip link add link t-dummy name t-dummy.100 type vlan id 100
$ ip link add name t-nlmon type nlmon
$ ip link set t-nlmon master team0
$ ip link set t-nlmon nomaster
$ ip link set t-dummy up
$ ip link set team0 up
$ ip link set t-dummy.100 down
$ ip link set t-dummy.100 master team0
When enslave a vlan device to team device and team device type is changed
from non-ether to ether, header_ops of team device is changed to
vlan_header_ops. That is incorrect and will trigger null-ptr-deref
for vlan->real_dev in vlan_dev_hard_header() because team device is not
a vlan device.
Cache eth_header_ops in team_setup(), then assign cached header_ops to
header_ops of team net device when its type is changed from non-ether
to ether to fix the bug.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 1d76efe1577b, lessThan: 1779eb51b9cc, status: affected, versionType: git
version: 1d76efe1577b, lessThan: a7fb47b97111, status: affected, versionType: git
version: 1d76efe1577b, lessThan: c5f6478686bb, status: affected, versionType: git
version: 1d76efe1577b, lessThan: b44dd92e2afd, status: affected, versionType: git
version: 1d76efe1577b, lessThan: cd05eec2ee0c, status: affected, versionType: git
version: 1d76efe1577b, lessThan: 2f0acb0736ec, status: affected, versionType: git
version: 1d76efe1577b, lessThan: cac50d9f5d87, status: affected, versionType: git
version: 1d76efe1577b, lessThan: 492032760127, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 3.7, status: affected
version: 0, lessThan: 3.7, status: unaffected, versionType: custom
version: 4.14.327, lessThanOrEqual: 4.14.*, status: unaffected, versionType: custom
version: 4.19.296, lessThanOrEqual: 4.19.*, status: unaffected, versionType: custom
version: 5.4.258, lessThanOrEqual: 5.4.*, status: unaffected, versionType: custom
version: 5.10.198, lessThanOrEqual: 5.10.*, status: unaffected, versionType: custom
version: 5.15.134, lessThanOrEqual: 5.15.*, status: unaffected, versionType: custom
version: 6.1.56, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.5.6, lessThanOrEqual: 6.5.*, status: unaffected, versionType: custom
version: 6.6, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
