- Description
- In the Linux kernel, the following vulnerability has been resolved: sch_htb: fix refcount leak in htb_parent_to_leaf_offload The commit ae81feb7338c ("sch_htb: fix null pointer dereference on a null new_q") fixes a NULL pointer dereference bug, but it is not correct. Because htb_graft_helper properly handles the case when new_q is NULL, and after the previous patch by skipping this call which creates an inconsistency : dev_queue->qdisc will still point to the old qdisc, but cl->parent->leaf.q will point to the new one (which will be noop_qdisc, because new_q was NULL). The code is based on an assumption that these two pointers are the same, so it can lead to refcount leaks. The correct fix is to add a NULL pointer check to protect qdisc_refcount_inc inside htb_parent_to_leaf_offload.
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- NVD status
- Analyzed
CVSS 3.1
- Type
- Primary
- Base score
- 5.5
- Impact score
- 3.6
- Exploitability score
- 1.8
- Vector string
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Severity
- MEDIUM
- Hype score
- Not currently trending
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "C68A4290-9FFF-4037-9467-4FF878E3085F",
"versionEndExcluding": "5.12.10",
"versionStartIncluding": "5.12"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "0CBAD0FC-C281-4666-AB2F-F8E6E1165DF7"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "96AC23B2-D46A-49D9-8203-8E1BEDCA8532"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "DA610E30-717C-4700-9F77-A3C9244F3BFD"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "1ECD33F5-85BE-430B-8F86-8D7BD560311D"
}
],
"operator": "OR"
}
]
}
]