GHSA-4H38-C385-VWJX
Vulnerability from github – Published: 2024-10-21 21:30 – Updated: 2024-10-25 21:31In the Linux kernel, the following vulnerability has been resolved:
net: napi: Prevent overflow of napi_defer_hard_irqs
In commit 6f8b12d661d0 ("net: napi: add hard irqs deferral feature") napi_defer_irqs was added to net_device and napi_defer_irqs_count was added to napi_struct, both as type int.
This value never goes below zero, so there is not reason for it to be a signed int. Change the type for both from int to u32, and add an overflow check to sysfs to limit the value to S32_MAX.
The limit of S32_MAX was chosen because the practical limit before this patch was S32_MAX (anything larger was an overflow) and thus there are no behavioral changes introduced. If the extra bit is needed in the future, the limit can be raised.
Before this patch:
$ sudo bash -c 'echo 2147483649 > /sys/class/net/eth4/napi_defer_hard_irqs' $ cat /sys/class/net/eth4/napi_defer_hard_irqs -2147483647
After this patch:
$ sudo bash -c 'echo 2147483649 > /sys/class/net/eth4/napi_defer_hard_irqs' bash: line 0: echo: write error: Numerical result out of range
Similarly, /sys/class/net/XXXXX/tx_queue_len is defined as unsigned:
include/linux/netdevice.h: unsigned int tx_queue_len;
And has an overflow check:
dev_change_tx_queue_len(..., unsigned long new_len):
if (new_len != (unsigned int)new_len) return -ERANGE;
{
"affected": [],
"aliases": [
"CVE-2024-50018"
],
"database_specific": {
"cwe_ids": [
"CWE-190"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-10-21T19:15:05Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: napi: Prevent overflow of napi_defer_hard_irqs\n\nIn commit 6f8b12d661d0 (\"net: napi: add hard irqs deferral feature\")\nnapi_defer_irqs was added to net_device and napi_defer_irqs_count was\nadded to napi_struct, both as type int.\n\nThis value never goes below zero, so there is not reason for it to be a\nsigned int. Change the type for both from int to u32, and add an\noverflow check to sysfs to limit the value to S32_MAX.\n\nThe limit of S32_MAX was chosen because the practical limit before this\npatch was S32_MAX (anything larger was an overflow) and thus there are\nno behavioral changes introduced. If the extra bit is needed in the\nfuture, the limit can be raised.\n\nBefore this patch:\n\n$ sudo bash -c \u0027echo 2147483649 \u003e /sys/class/net/eth4/napi_defer_hard_irqs\u0027\n$ cat /sys/class/net/eth4/napi_defer_hard_irqs\n-2147483647\n\nAfter this patch:\n\n$ sudo bash -c \u0027echo 2147483649 \u003e /sys/class/net/eth4/napi_defer_hard_irqs\u0027\nbash: line 0: echo: write error: Numerical result out of range\n\nSimilarly, /sys/class/net/XXXXX/tx_queue_len is defined as unsigned:\n\ninclude/linux/netdevice.h: unsigned int tx_queue_len;\n\nAnd has an overflow check:\n\ndev_change_tx_queue_len(..., unsigned long new_len):\n\n if (new_len != (unsigned int)new_len)\n return -ERANGE;",
"id": "GHSA-4h38-c385-vwjx",
"modified": "2024-10-25T21:31:26Z",
"published": "2024-10-21T21:30:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-50018"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/08062af0a52107a243f7608fd972edb54ca5b7f8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5e753b743d3b38a3e10be666c32c5434423d0093"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d694ad8b7e5004df86ecd415cb2320d543723672"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.