{"cve":"CVE-2023-52443","nvd":{"published":"2024-02-22T17:15:08.377","modified":"2026-06-17T06:42:42.347","status":"Modified","description":"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 <TASK>\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 </TASK>\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).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/0a12db736edbb4933e4274932aeea594b5876fa4","https://git.kernel.org/stable/c/1d8e62b5569cc1466ceb8a7e4872cf10160a9dcf","https://git.kernel.org/stable/c/55a8210c9e7d21ff2644809699765796d4bfb200","https://git.kernel.org/stable/c/5c0392fdafb0a2321311900be83ffa572bef8203","https://git.kernel.org/stable/c/5ff00408e5029d3550ee77f62dc15f1e15c47f87"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:45:59.823092188+00:00"},"epss":{"cve":"CVE-2023-52443","score":0.0024,"percentile":0.15153,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}