First published: Sat Mar 02 2024(Updated: )
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.
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Software | Affected Version | How to fix |
---|---|---|
redhat/kernel | <4.14.327 | 4.14.327 |
redhat/kernel | <4.19.296 | 4.19.296 |
redhat/kernel | <5.4.258 | 5.4.258 |
redhat/kernel | <5.10.198 | 5.10.198 |
redhat/kernel | <5.15.134 | 5.15.134 |
redhat/kernel | <6.1.56 | 6.1.56 |
redhat/kernel | <6.5.6 | 6.5.6 |
redhat/kernel | <6.6 | 6.6 |
Linux Linux kernel | >=3.7<4.14.327 | |
Linux Linux kernel | >=4.15<4.19.296 | |
Linux Linux kernel | >=4.20<5.4.258 | |
Linux Linux kernel | >=5.5<5.10.198 | |
Linux Linux kernel | >=5.11<5.15.134 | |
Linux Linux kernel | >=5.16<6.1.56 | |
Linux Linux kernel | >=6.2<6.5.6 | |
Linux Linux kernel | =6.6-rc1 | |
Linux Linux kernel | =6.6-rc2 |
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