From: Kent Overstreet <kent.overstreet@linux.dev>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
linux-bcachefs@vger.kernel.org, linux-mm@kvack.org,
Vlastimil Babka <vbabka@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
Uladzislau Rezki <urezki@gmail.com>,
Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH] mm: Drop INT_MAX limit from kvmalloc()
Date: Sun, 20 Oct 2024 16:10:51 -0400 [thread overview]
Message-ID: <6eo3gekf6twbnzhpsi2emz2s6sgtof6iba2rvbor7himmejoq5@qbfwtpbpvqoe> (raw)
In-Reply-To: <CAHk-=wiW_QZ9VS3Ho2Ff8ZDp-T6SomDFrVPWG3abs45LMZpxZQ@mail.gmail.com>
On Sun, Oct 20, 2024 at 12:09:58PM -0700, Linus Torvalds wrote:
> On Sun, 20 Oct 2024 at 12:09, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > How about you limit the amount of memory you use in the first place instead?
>
> .. and to clarify: we're not making other parts of the kernel less
> robust because *you* are doing something stupid and odd.
But back to the actual topic at hand, the security angle - while we
don't have ubsan style checks for integer truncation (the real concern),
we do have sysbot + kasan, which does cover this pretty thoroughly.
And the INT_MAX check wouldn't catch truncation anyways - it'd only
catch integer _underflow_, but allocation size calculations pretty much
as a rule never use subtractions, so I don't think this check was ever
worth much to begin with.
next prev parent reply other threads:[~2024-10-20 20:11 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-19 21:00 Kent Overstreet
2024-10-20 11:45 ` Lorenzo Stoakes
2024-10-20 13:00 ` Kent Overstreet
2024-10-20 16:44 ` Lorenzo Stoakes
2024-10-20 17:03 ` Kent Overstreet
2024-10-20 18:46 ` Linus Torvalds
2024-10-20 18:53 ` Kent Overstreet
2024-10-20 19:09 ` Linus Torvalds
2024-10-20 19:09 ` Linus Torvalds
2024-10-20 19:16 ` Kent Overstreet
2024-10-21 16:15 ` Uladzislau Rezki
2024-10-20 20:10 ` Kent Overstreet [this message]
2024-10-20 20:19 ` Linus Torvalds
2024-10-20 20:29 ` Kent Overstreet
2024-10-20 20:54 ` Linus Torvalds
2024-10-20 21:21 ` Linus Torvalds
2024-10-20 21:40 ` Kent Overstreet
2024-10-27 19:58 ` Kent Overstreet
2024-10-20 21:29 ` Kent Overstreet
2024-10-20 21:30 ` Linus Torvalds
2024-10-20 21:42 ` Kent Overstreet
2024-10-20 21:51 ` Joshua Ashton
2024-10-20 21:57 ` Kent Overstreet
2024-10-21 8:46 ` Janpieter Sollie
2024-10-21 9:22 ` Janpieter Sollie
2024-10-20 19:10 ` Kent Overstreet
2024-10-20 19:53 ` Vlastimil Babka
2024-10-20 20:08 ` Kent Overstreet
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