Received-SPF: pass (google.com: domain of linux-kernel+bounces-180159-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
From: Christian Brauner <brauner@kernel.org>
To: Justin Stitt <justinstitt@google.com>
Cc: Christian Brauner <brauner@kernel.org>,
	linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev,
	linux-hardening@vger.kernel.org,
	Kees Cook <keescook@chromium.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Jan Kara <jack@suse.cz>,
	Nathan Chancellor <nathan@kernel.org>,
	Bill Wendling <morbo@google.com>,
	Nick Desaulniers <ndesaulniers@google.com>
Subject: Re: [PATCH v2] fs: remove accidental overflow during wraparound check
Date: Wed, 15 May 2024 18:44:45 +0200
Message-ID: <20240515-rentier-abwinken-f9c282783235@brauner>
In-Reply-To: <20240513-b4-sio-vfs_fallocate-v2-1-db415872fb16@google.com>
References: <20240513-b4-sio-vfs_fallocate-v2-1-db415872fb16@google.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit

On Mon, 13 May 2024 17:50:30 +0000, Justin Stitt wrote:
> Running syzkaller with the newly enabled signed integer overflow
> sanitizer produces this report:
> 
> [  195.401651] ------------[ cut here ]------------
> [  195.404808] UBSAN: signed-integer-overflow in ../fs/open.c:321:15
> [  195.408739] 9223372036854775807 + 562984447377399 cannot be represented in type 'loff_t' (aka 'long long')
> [  195.414683] CPU: 1 PID: 703 Comm: syz-executor.0 Not tainted 6.8.0-rc2-00039-g14de58dbe653-dirty #11
> [  195.420138] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
> [  195.425804] Call Trace:
> [  195.427360]  <TASK>
> [  195.428791]  dump_stack_lvl+0x93/0xd0
> [  195.431150]  handle_overflow+0x171/0x1b0
> [  195.433640]  vfs_fallocate+0x459/0x4f0
> ...
> [  195.490053] ------------[ cut here ]------------
> [  195.493146] UBSAN: signed-integer-overflow in ../fs/open.c:321:61
> [  195.497030] 9223372036854775807 + 562984447377399 cannot be represented in type 'loff_t' (aka 'long long)
> [  195.502940] CPU: 1 PID: 703 Comm: syz-executor.0 Not tainted 6.8.0-rc2-00039-g14de58dbe653-dirty #11
> [  195.508395] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
> [  195.514075] Call Trace:
> [  195.515636]  <TASK>
> [  195.517000]  dump_stack_lvl+0x93/0xd0
> [  195.519255]  handle_overflow+0x171/0x1b0
> [  195.521677]  vfs_fallocate+0x4cb/0x4f0
> [  195.524033]  __x64_sys_fallocate+0xb2/0xf0
> 
> [...]

Applied to the vfs.misc branch of the vfs/vfs.git tree.
Patches in the vfs.misc branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.misc

[1/1] fs: remove accidental overflow during wraparound check
      https://git.kernel.org/vfs/vfs/c/c01a23b6fbd1