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Reeves" To: Mikulas Patocka Cc: dm-devel@lists.linux.dev, Tony Asleson , Alasdair Kergon , Zdenek Kabelac , Benjamin Marzinski Subject: Re: [PATCH] dm: fix a buffer overflow in ioctl processing Message-ID: References: <510b5754-3944-6b4e-03b8-f3a7dc137944@redhat.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <510b5754-3944-6b4e-03b8-f3a7dc137944@redhat.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 7bU_4HrOahUIAL9qhy2MLbdON4mZFSghbmob1L8jPIs_1775752971 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Apr 09, 2026 at 05:49:58PM +0200, Mikulas Patocka wrote: > Luckily, this bug has no security implications because: > 1. Only root can issue device mapper ioctls > 2. The commonly used libraries that communicate with device mapper > (libdevmapper and devicemapper-rs) use buffer size that is aligned to > 8 bytes - thus, "outptr = align_ptr(outptr)" can't overshoot the input > buffer and the bug can't happen accidentally > > Reported-by: Tony Asleson > Signed-off-by: Mikulas Patocka Reviewed-by: Bryn M. Reeves