linux-kernel - Re: [PATCH] iommufd: viommu: free memory allocated by kvcalloc() using kvfree()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5f0fa597-2f60-4110-8c52-6d006f5707b3@foss.arm.com>
Date: Fri, 15 Aug 2025 15:15:33 +0100
From: Robin Murphy <robin.murphy@...s.arm.com>
To: Markus Elfring <Markus.Elfring@....de>,
 Akhilesh Patil <akhilesh@...iitb.ac.in>, iommu@...ts.linux.dev
Cc: akhileshpatilvnit@...il.com, LKML <linux-kernel@...r.kernel.org>,
 Jason Gunthorpe <jgg@...dia.com>, Jason Gunthorpe <jgg@...pe.ca>,
 Jörg Rödel <joro@...tes.org>,
 Kevin Tian <kevin.tian@...el.com>, Lu Baolu <baolu.lu@...ux.intel.com>,
 Nicolin Chen <nicolinc@...dia.com>, Pranjal Shrivastava <praan@...gle.com>,
 Shuah Khan <skhan@...uxfoundation.org>, Will Deacon <will@...nel.org>
Subject: Re: [PATCH] iommufd: viommu: free memory allocated by kvcalloc()
 using kvfree()

On 15/08/2025 2:42 pm, Markus Elfring wrote:
>> Use kvfree() instead of kfree() to free pages allocated by kvcalloc()
>> in iommufs_hw_queue_alloc_phys() to fix potential memory corruption.
>> Ensure the memory is properly freed, as kvcalloc may internally use
>> vmalloc or kmalloc depending on available memory in the system.
> 
> Will another bit of background information become helpful
> for an improved change description?

No it will not. Please stop pointlessly nitpicking. A thing that is 
allocated with kv*alloc() must be freed with kvfree(); that alone is all 
that needs to be said to explain and justify any patch fixing this 
particular bug.

Thanks,
Robin.