CVE - CVE-2023-52443

CVE-ID
CVE-2023-52443	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
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: <TASK> ? strlen+0x1e/0xa0 aa_policy_init+0x1bb/0x230 aa_alloc_profile+0xb1/0x480 unpack_profile+0x3bc/0x4960 aa_unpack+0x309/0x15e0 aa_replace_profiles+0x213/0x33c0 policy_update+0x261/0x370 profile_replace+0x20e/0x2a0 vfs_write+0x2af/0xe00 ksys_write+0x126/0x250 do_syscall_64+0x46/0xf0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 </TASK> ---[ end trace 0000000000000000 ]--- RIP: 0010:strlen+0x1e/0xa0 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).
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/0a12db736edbb4933e4274932aeea594b5876fa4 URL:https://git.kernel.org/stable/c/0a12db736edbb4933e4274932aeea594b5876fa4 MISC:https://git.kernel.org/stable/c/1d8e62b5569cc1466ceb8a7e4872cf10160a9dcf URL:https://git.kernel.org/stable/c/1d8e62b5569cc1466ceb8a7e4872cf10160a9dcf MISC:https://git.kernel.org/stable/c/55a8210c9e7d21ff2644809699765796d4bfb200 URL:https://git.kernel.org/stable/c/55a8210c9e7d21ff2644809699765796d4bfb200 MISC:https://git.kernel.org/stable/c/5c0392fdafb0a2321311900be83ffa572bef8203 URL:https://git.kernel.org/stable/c/5c0392fdafb0a2321311900be83ffa572bef8203 MISC:https://git.kernel.org/stable/c/5ff00408e5029d3550ee77f62dc15f1e15c47f87 URL:https://git.kernel.org/stable/c/5ff00408e5029d3550ee77f62dc15f1e15c47f87 MISC:https://git.kernel.org/stable/c/77ab09b92f16c8439a948d1af489196953dc4a0e URL:https://git.kernel.org/stable/c/77ab09b92f16c8439a948d1af489196953dc4a0e MISC:https://git.kernel.org/stable/c/9286ee97aa4803d99185768735011d0d65827c9e URL:https://git.kernel.org/stable/c/9286ee97aa4803d99185768735011d0d65827c9e MISC:https://git.kernel.org/stable/c/9d4fa5fe2b1d56662afd14915a73b4d0783ffa45 URL:https://git.kernel.org/stable/c/9d4fa5fe2b1d56662afd14915a73b4d0783ffa45
Assigning CNA
kernel.org
Date Record Created
20240220	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240220)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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