ghsa-3hp3-h35p-gqg4
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
apparmor: avoid crash when parsed profile name is empty
When processing a packed profile in unpack_profile() described like
"profile :ns::samba-dcerpcd /usr/lib*/samba/{,samba/}samba-dcerpcd {...}"
a string ":samba-dcerpcd" is unpacked as a fully-qualified name and then passed to aa_splitn_fqname().
aa_splitn_fqname() treats ":samba-dcerpcd" as only containing a namespace. Thus it returns NULL for tmpname, meanwhile tmpns is non-NULL. Later aa_alloc_profile() crashes as the new profile name is NULL now.
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 6 PID: 1657 Comm: apparmor_parser Not tainted 6.7.0-rc2-dirty #16
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
RIP: 0010:strlen+0x1e/0xa0
Call Trace:
It seems such behaviour of aa_splitn_fqname() is expected and checked in other places where it is called (e.g. aa_remove_profiles). Well, there is an explicit comment "a ns name without a following profile is allowed" inside.
AFAICS, nothing can prevent unpacked "name" to be in form like ":samba-dcerpcd" - it is passed from userspace.
Deny the whole profile set replacement in such case and inform user with EPROTO and an explaining message.
Found by Linux Verification Center (linuxtesting.org).
{
"affected": [],
"aliases": [
"CVE-2023-52443"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-02-22T17:15:08Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: avoid crash when parsed profile name is empty\n\nWhen processing a packed profile in unpack_profile() described like\n\n \"profile :ns::samba-dcerpcd /usr/lib*/samba/{,samba/}samba-dcerpcd {...}\"\n\na string \":samba-dcerpcd\" is unpacked as a fully-qualified name and then\npassed to aa_splitn_fqname().\n\naa_splitn_fqname() treats \":samba-dcerpcd\" as only containing a namespace.\nThus it returns NULL for tmpname, meanwhile tmpns is non-NULL. Later\naa_alloc_profile() crashes as the new profile name is NULL now.\n\ngeneral protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI\nKASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\nCPU: 6 PID: 1657 Comm: apparmor_parser Not tainted 6.7.0-rc2-dirty #16\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014\nRIP: 0010:strlen+0x1e/0xa0\nCall Trace:\n \u003cTASK\u003e\n ? strlen+0x1e/0xa0\n aa_policy_init+0x1bb/0x230\n aa_alloc_profile+0xb1/0x480\n unpack_profile+0x3bc/0x4960\n aa_unpack+0x309/0x15e0\n aa_replace_profiles+0x213/0x33c0\n policy_update+0x261/0x370\n profile_replace+0x20e/0x2a0\n vfs_write+0x2af/0xe00\n ksys_write+0x126/0x250\n do_syscall_64+0x46/0xf0\n entry_SYSCALL_64_after_hwframe+0x6e/0x76\n \u003c/TASK\u003e\n---[ end trace 0000000000000000 ]---\nRIP: 0010:strlen+0x1e/0xa0\n\nIt seems such behaviour of aa_splitn_fqname() is expected and checked in\nother places where it is called (e.g. aa_remove_profiles). Well, there\nis an explicit comment \"a ns name without a following profile is allowed\"\ninside.\n\nAFAICS, nothing can prevent unpacked \"name\" to be in form like\n\":samba-dcerpcd\" - it is passed from userspace.\n\nDeny the whole profile set replacement in such case and inform user with\nEPROTO and an explaining message.\n\nFound by Linux Verification Center (linuxtesting.org).",
"id": "GHSA-3hp3-h35p-gqg4",
"modified": "2024-06-27T12:30:43Z",
"published": "2024-02-22T18:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-52443"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0a12db736edbb4933e4274932aeea594b5876fa4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1d8e62b5569cc1466ceb8a7e4872cf10160a9dcf"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/55a8210c9e7d21ff2644809699765796d4bfb200"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5c0392fdafb0a2321311900be83ffa572bef8203"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5ff00408e5029d3550ee77f62dc15f1e15c47f87"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/77ab09b92f16c8439a948d1af489196953dc4a0e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9286ee97aa4803d99185768735011d0d65827c9e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9d4fa5fe2b1d56662afd14915a73b4d0783ffa45"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00016.html"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html"
}
],
"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"
}
]
}
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