cvelist/2024/41xxx/CVE-2024-41045.json
2024-11-05 10:01:30 +00:00

102 lines
5.8 KiB
JSON

{
"data_version": "4.0",
"data_type": "CVE",
"data_format": "MITRE",
"CVE_data_meta": {
"ID": "CVE-2024-41045",
"ASSIGNER": "cve@kernel.org",
"STATE": "PUBLIC"
},
"description": {
"description_data": [
{
"lang": "eng",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Defer work in bpf_timer_cancel_and_free\n\nCurrently, the same case as previous patch (two timer callbacks trying\nto cancel each other) can be invoked through bpf_map_update_elem as\nwell, or more precisely, freeing map elements containing timers. Since\nthis relies on hrtimer_cancel as well, it is prone to the same deadlock\nsituation as the previous patch.\n\nIt would be sufficient to use hrtimer_try_to_cancel to fix this problem,\nas the timer cannot be enqueued after async_cancel_and_free. Once\nasync_cancel_and_free has been done, the timer must be reinitialized\nbefore it can be armed again. The callback running in parallel trying to\narm the timer will fail, and freeing bpf_hrtimer without waiting is\nsufficient (given kfree_rcu), and bpf_timer_cb will return\nHRTIMER_NORESTART, preventing the timer from being rearmed again.\n\nHowever, there exists a UAF scenario where the callback arms the timer\nbefore entering this function, such that if cancellation fails (due to\ntimer callback invoking this routine, or the target timer callback\nrunning concurrently). In such a case, if the timer expiration is\nsignificantly far in the future, the RCU grace period expiration\nhappening before it will free the bpf_hrtimer state and along with it\nthe struct hrtimer, that is enqueued.\n\nHence, it is clear cancellation needs to occur after\nasync_cancel_and_free, and yet it cannot be done inline due to deadlock\nissues. We thus modify bpf_timer_cancel_and_free to defer work to the\nglobal workqueue, adding a work_struct alongside rcu_head (both used at\n_different_ points of time, so can share space).\n\nUpdate existing code comments to reflect the new state of affairs."
}
]
},
"problemtype": {
"problemtype_data": [
{
"description": [
{
"lang": "eng",
"value": "n/a"
}
]
}
]
},
"affects": {
"vendor": {
"vendor_data": [
{
"vendor_name": "Linux",
"product": {
"product_data": [
{
"product_name": "Linux",
"version": {
"version_data": [
{
"version_affected": "<",
"version_name": "b00628b1c7d5",
"version_value": "7aa5a19279c3"
},
{
"version_value": "not down converted",
"x_cve_json_5_version_data": {
"versions": [
{
"version": "5.15",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.15",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.9.10",
"lessThanOrEqual": "6.9.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.10",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
],
"defaultStatus": "affected"
}
}
]
}
}
]
}
}
]
}
},
"references": {
"reference_data": [
{
"url": "https://git.kernel.org/stable/c/7aa5a19279c3639ae8b758b63f05d0c616a39fa1",
"refsource": "MISC",
"name": "https://git.kernel.org/stable/c/7aa5a19279c3639ae8b758b63f05d0c616a39fa1"
},
{
"url": "https://git.kernel.org/stable/c/a6fcd19d7eac1335eb76bc16b6a66b7f574d1d69",
"refsource": "MISC",
"name": "https://git.kernel.org/stable/c/a6fcd19d7eac1335eb76bc16b6a66b7f574d1d69"
}
]
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