ghsa-vhwp-83w8-m7pm
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: felix: suppress non-changes to the tagging protocol
The way in which dsa_tree_change_tag_proto() works is that when dsa_tree_notify() fails, it doesn't know whether the operation failed mid way in a multi-switch tree, or it failed for a single-switch tree. So even though drivers need to fail cleanly in ds->ops->change_tag_protocol(), DSA will still call dsa_tree_notify() again, to restore the old tag protocol for potential switches in the tree where the change did succeeed (before failing for others).
This means for the felix driver that if we report an error in felix_change_tag_protocol(), we'll get another call where proto_ops == old_proto_ops. If we proceed to act upon that, we may do unexpected things. For example, we will call dsa_tag_8021q_register() twice in a row, without any dsa_tag_8021q_unregister() in between. Then we will actually call dsa_tag_8021q_unregister() via old_proto_ops->teardown, which (if it manages to run at all, after walking through corrupted data structures) will leave the ports inoperational anyway.
The bug can be readily reproduced if we force an error while in tag_8021q mode; this crashes the kernel.
echo ocelot-8021q > /sys/class/net/eno2/dsa/tagging echo edsa > /sys/class/net/eno2/dsa/tagging # -EPROTONOSUPPORT
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000014 Call trace: vcap_entry_get+0x24/0x124 ocelot_vcap_filter_del+0x198/0x270 felix_tag_8021q_vlan_del+0xd4/0x21c dsa_switch_tag_8021q_vlan_del+0x168/0x2cc dsa_switch_event+0x68/0x1170 dsa_tree_notify+0x14/0x34 dsa_port_tag_8021q_vlan_del+0x84/0x110 dsa_tag_8021q_unregister+0x15c/0x1c0 felix_tag_8021q_teardown+0x16c/0x180 felix_change_tag_protocol+0x1bc/0x230 dsa_switch_event+0x14c/0x1170 dsa_tree_change_tag_proto+0x118/0x1c0
{
"affected": [],
"aliases": [
"CVE-2022-50063"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-06-18T11:15:35Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: felix: suppress non-changes to the tagging protocol\n\nThe way in which dsa_tree_change_tag_proto() works is that when\ndsa_tree_notify() fails, it doesn\u0027t know whether the operation failed\nmid way in a multi-switch tree, or it failed for a single-switch tree.\nSo even though drivers need to fail cleanly in\nds-\u003eops-\u003echange_tag_protocol(), DSA will still call dsa_tree_notify()\nagain, to restore the old tag protocol for potential switches in the\ntree where the change did succeeed (before failing for others).\n\nThis means for the felix driver that if we report an error in\nfelix_change_tag_protocol(), we\u0027ll get another call where proto_ops ==\nold_proto_ops. If we proceed to act upon that, we may do unexpected\nthings. For example, we will call dsa_tag_8021q_register() twice in a\nrow, without any dsa_tag_8021q_unregister() in between. Then we will\nactually call dsa_tag_8021q_unregister() via old_proto_ops-\u003eteardown,\nwhich (if it manages to run at all, after walking through corrupted data\nstructures) will leave the ports inoperational anyway.\n\nThe bug can be readily reproduced if we force an error while in\ntag_8021q mode; this crashes the kernel.\n\necho ocelot-8021q \u003e /sys/class/net/eno2/dsa/tagging\necho edsa \u003e /sys/class/net/eno2/dsa/tagging # -EPROTONOSUPPORT\n\nUnable to handle kernel NULL pointer dereference at virtual address 0000000000000014\nCall trace:\n vcap_entry_get+0x24/0x124\n ocelot_vcap_filter_del+0x198/0x270\n felix_tag_8021q_vlan_del+0xd4/0x21c\n dsa_switch_tag_8021q_vlan_del+0x168/0x2cc\n dsa_switch_event+0x68/0x1170\n dsa_tree_notify+0x14/0x34\n dsa_port_tag_8021q_vlan_del+0x84/0x110\n dsa_tag_8021q_unregister+0x15c/0x1c0\n felix_tag_8021q_teardown+0x16c/0x180\n felix_change_tag_protocol+0x1bc/0x230\n dsa_switch_event+0x14c/0x1170\n dsa_tree_change_tag_proto+0x118/0x1c0",
"id": "GHSA-vhwp-83w8-m7pm",
"modified": "2025-06-18T12:30:45Z",
"published": "2025-06-18T12:30:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-50063"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4c46bb49460ee14c69629e813640d8b929e88941"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8e432f157c3edc5a97a7244c666589a438f5e4d4"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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