From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793906960; b=gjYxXONgTw7qGu68/19Z6xmQQjovw6uKUfJEh7BhtibR2Ok6sXgHD/hZBay+tSe+Q/8s dwUawyXJYUpykn7yXWJQgeboMYPzfcuH8hO4RPqbUSDYoxmd+N2ys1iq+3s31gHTJnq0B 3W2W+/FLT3L+pBuSLC/9A/mWs8Z8VV+p9YnLUcFSP+NAGzGFyf0SFW4r600xrelyBO/Hi fhzlwwaAEItHjP3Yapp6Hx2vLYBt2OTMHwj6kU+fA8L0mxAfaAfXO2s8ZX8zVMhn+h9bi zVbiP+qFEJQ6MLAICrYPFjbEgueN8zMtzmoXDOGtm66sAuh6jqzcbIWDsDPlz4PIeLA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793906960; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=Qw513NKzixnVetQs2aPch799inLwFwvqjGlTZsHFgHc=; b=JF7A80URZJsZxlv9VeG7Uhz532Ydulkk0bZZxjcFowAIy2ifVW5j0SpMh3tO0eZPfK6Y lIoHbRqmBsQ3q41yn3EPbELK/1FhdE9W1kOdmi98P1GBxrz2rj9iWBKlnv7PPhweYkdrz tZd8DJh98nsc7YFk5HU/mQdD691bQGZlwlb74E0BQHQFwKbpToF0h1aylFmslTO/o+7XY d4JTv5SAiGLjCBYEzgEvYOSLFn4tBGFnwFOJy/RgWqMTNaGZitTOX1INC0WOLdc0w70Oc qMxMv3habGhWfICaVsKyA93S/N/P3ZWJrLtyRbyvL3sOq9cvjmVpTINFT9QtZYJ6GkQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=WP5zysBl; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 910BB606D83D; Thu, 5 Nov 2026 19:29:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=WP5zysBl Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF3F21F000C1; Thu, 5 Nov 2026 19:29:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793906960; bh=Qw513NKzixnVetQs2aPch799inLwFwvqjGlTZsHFgHc=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=WP5zysBlV6QoE+ebdO994NPOQCHtVK69BSl7GA0TkgCejzw4yv+Qi/dIb/BiTtwJI CtwiPcppWeOxu8qxGDLb2NNs4muOnWOkbdTfgMZetnT6EYIraiEzVZgwrSfKYuy20p lq1YQ+ODYgN/fNYKxtV+Y3MBG2phtgSlbN/PnX4DhhLfO11dC92+odtKZZNAdRC5BY cOK2uw6yB5xGSlQ2pqLEJNTrF9NrssiHaYNsRIIVDX79TmltA0T6xLv6ahSmhYnicd 7xH40xuqXjCm2XXdHJHYyElfh7nUle5CnSYYX4imcJF/N71eKI1RK/06V3FFapNV/j F1VfvpFqH1/NA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH RESEND v2 15/51] PCI/proc: don't truncate the position of config space accesses Reply-To: sashiko-reviews@lists.linux.dev To: "Christian Brauner" Cc: "Linus Torvalds" , "Jann Horn" , "Josef Bacik" , "Chris Mason" , "Jeff Layton" , NeilBrown , "Eric Dumazet" , "Thomas Gleixner" , "Al Viro" , "Jonathan Corbet" , "Christoph Hellwig" , "Greg Kroah-Hartman" , "Joel Granados" , "Kees Cook" , "Jan Kara" , "Jan Kara" , linux-s390@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, linux-m68k@lists.linux-m68k.org, linux-serial@vger.kernel.org, "Takashi Iwai" , linux-ext4@vger.kernel.org, "Chuck Lever" , tytso@mit.edu, "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261104-work-procfs-bugfixes-v2-15-021c84d852e0@kernel.org> References: <20261104-work-procfs-bugfixes-v2-0-021c84d852e0@kernel.org> <20261104-work-procfs-bugfixes-v2-15-021c84d852e0@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 05 Nov 2026 19:29:18 +0000 X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > proc_bus_pci_write() truncates the file position to an int. A pwrite() > at an offset like 0xfffff000 turns it negative, the check against the > size of the config space passes and the count it clamps to ends up > larger than what was written. The loop then reads past the end of the > caller's buffer and writes all of it into config space at negative > offsets, which pci_user_write_config_*() pass on to the config > accessors unchecked. The write also returns more than it was asked to > write. >=20 > An offset above 4G that truncates to a small positive value writes to > the start of config space instead. proc_bus_pci_read() keeps the > position in an unsigned int, so a read at such an offset returns the > start of config space instead of hitting EOF. >=20 > Check the position against the size of the config space before > narrowing it. >=20 > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Cc: stable@vger.kernel.org > Signed-off-by: Christian Brauner (Amutable) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261104-work-procf= s-bugfixes-v2-0-021c84d852e0@kernel.org?part=3D15