{"id":"CVE-2023-52443","summary":"apparmor: avoid crash when parsed profile name is empty","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).","modified":"2026-04-02T09:42:17.694885Z","published":"2024-02-22T16:13:31.154Z","related":["SUSE-SU-2024:0855-1","SUSE-SU-2024:0856-1","SUSE-SU-2024:0857-1","SUSE-SU-2024:0858-1","SUSE-SU-2024:0900-1","SUSE-SU-2024:0900-2","SUSE-SU-2024:0910-1","SUSE-SU-2024:0925-1","SUSE-SU-2024:0926-1","SUSE-SU-2024:0975-1","SUSE-SU-2024:0976-1","SUSE-SU-2024:0977-1","USN-6818-2","USN-6819-2"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52443.json","cna_assigner":"Linux"},"references":[{"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"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52443.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-52443"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"04dc715e24d0820bf8740e1a1135ed61fe162bc8"},{"fixed":"9286ee97aa4803d99185768735011d0d65827c9e"},{"fixed":"1d8e62b5569cc1466ceb8a7e4872cf10160a9dcf"},{"fixed":"5ff00408e5029d3550ee77f62dc15f1e15c47f87"},{"fixed":"0a12db736edbb4933e4274932aeea594b5876fa4"},{"fixed":"9d4fa5fe2b1d56662afd14915a73b4d0783ffa45"},{"fixed":"5c0392fdafb0a2321311900be83ffa572bef8203"},{"fixed":"77ab09b92f16c8439a948d1af489196953dc4a0e"},{"fixed":"55a8210c9e7d21ff2644809699765796d4bfb200"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-52443.json"}}],"schema_version":"1.7.5"}