linux-kernel - Re: [PATCH v7 06/17] mm/nommu: fix the last places where vma is not locked before being attached

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: <lravkk2p3gm4x75d7ut4d4godowaguliciuixs5exlpgfzpc5o@nwtcwqyf46mq>
Date: Tue, 7 Jan 2025 12:51:31 -0500
From: "Liam R. Howlett" <Liam.Howlett@...cle.com>
To: Suren Baghdasaryan <surenb@...gle.com>
Cc: akpm@...ux-foundation.org, peterz@...radead.org, willy@...radead.org,
        lorenzo.stoakes@...cle.com, mhocko@...e.com, vbabka@...e.cz,
        hannes@...xchg.org, mjguzik@...il.com, oliver.sang@...el.com,
        mgorman@...hsingularity.net, david@...hat.com, peterx@...hat.com,
        oleg@...hat.com, dave@...olabs.net, paulmck@...nel.org,
        brauner@...nel.org, dhowells@...hat.com, hdanton@...a.com,
        hughd@...gle.com, lokeshgidra@...gle.com, minchan@...gle.com,
        jannh@...gle.com, shakeel.butt@...ux.dev, souravpanda@...gle.com,
        pasha.tatashin@...een.com, klarasmodin@...il.com, corbet@....net,
        linux-doc@...r.kernel.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, kernel-team@...roid.com
Subject: Re: [PATCH v7 06/17] mm/nommu: fix the last places where vma is not
 locked before being attached

* Suren Baghdasaryan <surenb@...gle.com> [241226 12:07]:
> nommu configuration has two places where vma gets attached to the vma tree
> without write-locking it. Add the missing locks to ensure vma is always
> locked before it's attached.

Does the delete side need to write lock as well?

> 
> Signed-off-by: Suren Baghdasaryan <surenb@...gle.com>
> ---
>  mm/nommu.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/mm/nommu.c b/mm/nommu.c
> index 72c8c505836c..1754e84e5758 100644
> --- a/mm/nommu.c
> +++ b/mm/nommu.c
> @@ -1189,6 +1189,7 @@ unsigned long do_mmap(struct file *file,
>  		goto error_just_free;
>  
>  	setup_vma_to_mm(vma, current->mm);
> +	vma_start_write(vma);
>  	current->mm->map_count++;
>  	/* add the VMA to the tree */
>  	vma_iter_store(&vmi, vma, true);
> @@ -1356,6 +1357,7 @@ static int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
>  
>  	setup_vma_to_mm(vma, mm);
>  	setup_vma_to_mm(new, mm);
> +	vma_start_write(new);
>  	vma_iter_store(vmi, new, true);
>  	mm->map_count++;
>  	return 0;
> -- 
> 2.47.1.613.gc27f4b7a9f-goog
>