From: Keith Busch <kbusch@kernel.org>
To: veygax <veyga@veygax.dev>
Cc: Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@kernel.dk>,
"io-uring@vger.kernel.org" <io-uring@vger.kernel.org>,
Caleb Sander Mateos <csander@purestorage.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] io_uring/rsrc: fix slab-out-of-bounds in io_buffer_register_bvec
Date: Thu, 18 Dec 2025 08:56:43 +0800 [thread overview]
Message-ID: <aUNRS1Qiaiqo1scX@kbusch-mbp> (raw)
In-Reply-To: <f1522c5d-febf-4e51-b534-c0ffa719d555@veygax.dev>
On Thu, Dec 18, 2025 at 12:37:47AM +0000, veygax wrote:
> /*
> * Add pages to bio manually.
> * We use physically contiguous pages to trick blk_rq_nr_phys_segments
> * into returning 1 segment.
> * We use multiple bvec entries to trick the loop in io_buffer_register_bvec
> * into writing out of bounds.
> */
> for (i = 0; i < num_bvecs; i++) {
> struct bio_vec *bv = &bio->bi_io_vec[i];
> bv->bv_page = page + i;
> bv->bv_len = PAGE_SIZE;
> bv->bv_offset = 0;
> bio->bi_vcnt++;
> bio->bi_iter.bi_size += PAGE_SIZE;
> }
I believe you're supposed to use the bio_add_page() API rather than open
code the bvec setup.
next prev parent reply other threads:[~2025-12-18 0:56 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-17 21:04 [PATCH] io_uring/rsrc: fix slab-out-of-bounds in io_buffer_register_bvec veygax
2025-12-17 21:22 ` Caleb Sander Mateos
2025-12-18 0:32 ` Ming Lei
2025-12-18 0:37 ` veygax
2025-12-18 0:56 ` Keith Busch [this message]
2025-12-18 1:13 ` veygax
2025-12-18 2:58 ` Ming Lei
2025-12-18 23:00 ` Keith Busch
2025-12-19 3:28 ` Jens Axboe
2025-12-19 5:33 ` Christoph Hellwig
2025-12-21 23:29 ` Keith Busch
2025-12-22 22:08 ` Christoph Hellwig
2025-12-22 1:02 ` veygax
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