ghsa-39cv-hx7c-vjcq
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net_sched: sch_sfq: move the limit validation
It is not sufficient to directly validate the limit on the data that the user passes as it can be updated based on how the other parameters are changed.
Move the check at the end of the configuration update process to also catch scenarios where the limit is indirectly updated, for example with the following configurations:
tc qdisc add dev dummy0 handle 1: root sfq limit 2 flows 1 depth 1 tc qdisc add dev dummy0 handle 1: root sfq limit 2 flows 1 divisor 1
This fixes the following syzkaller reported crash:
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:203:6
index 65535 is out of range for type 'struct sfq_head[128]'
CPU: 1 UID: 0 PID: 3037 Comm: syz.2.16 Not tainted 6.14.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
{
"affected": [],
"aliases": [
"CVE-2025-37752"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-05-01T13:15:53Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet_sched: sch_sfq: move the limit validation\n\nIt is not sufficient to directly validate the limit on the data that\nthe user passes as it can be updated based on how the other parameters\nare changed.\n\nMove the check at the end of the configuration update process to also\ncatch scenarios where the limit is indirectly updated, for example\nwith the following configurations:\n\ntc qdisc add dev dummy0 handle 1: root sfq limit 2 flows 1 depth 1\ntc qdisc add dev dummy0 handle 1: root sfq limit 2 flows 1 divisor 1\n\nThis fixes the following syzkaller reported crash:\n\n------------[ cut here ]------------\nUBSAN: array-index-out-of-bounds in net/sched/sch_sfq.c:203:6\nindex 65535 is out of range for type \u0027struct sfq_head[128]\u0027\nCPU: 1 UID: 0 PID: 3037 Comm: syz.2.16 Not tainted 6.14.0-rc2-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x201/0x300 lib/dump_stack.c:120\n ubsan_epilogue lib/ubsan.c:231 [inline]\n __ubsan_handle_out_of_bounds+0xf5/0x120 lib/ubsan.c:429\n sfq_link net/sched/sch_sfq.c:203 [inline]\n sfq_dec+0x53c/0x610 net/sched/sch_sfq.c:231\n sfq_dequeue+0x34e/0x8c0 net/sched/sch_sfq.c:493\n sfq_reset+0x17/0x60 net/sched/sch_sfq.c:518\n qdisc_reset+0x12e/0x600 net/sched/sch_generic.c:1035\n tbf_reset+0x41/0x110 net/sched/sch_tbf.c:339\n qdisc_reset+0x12e/0x600 net/sched/sch_generic.c:1035\n dev_reset_queue+0x100/0x1b0 net/sched/sch_generic.c:1311\n netdev_for_each_tx_queue include/linux/netdevice.h:2590 [inline]\n dev_deactivate_many+0x7e5/0xe70 net/sched/sch_generic.c:1375",
"id": "GHSA-39cv-hx7c-vjcq",
"modified": "2025-06-27T12:31:13Z",
"published": "2025-05-01T15:31:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-37752"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1348214fa042a71406964097e743c87a42c85a49"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5e5e1fcc1b8ed57f902c424c5d9b328a3a19073d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6c589aa318023690f1606c666a7fb5f4c1c9c219"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7d62ded97db6b7c94c891f704151f372b1ba4688"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b36a68192037d1614317a09b0d78c7814e2eecf9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b3bf8f63e6179076b57c9de660c9f80b5abefe70"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d2718324f9e329b10ddc091fba5a0ba2b9d4d96a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f86293adce0c201cfabb283ef9d6f21292089bb8"
}
],
"schema_version": "1.4.0",
"severity": []
}
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.