From: Kees Cook <kees@kernel.org>
To: Jan Hendrik Farr <kernel@jfarr.cc>
Cc: Alan Huang <mmpgouride@gmail.com>,
kent.overstreet@linux.dev,
Thorsten Blum <thorsten.blum@toblux.com>,
Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
Nathan Chancellor <nathan@kernel.org>,
Bill Wendling <morbo@google.com>,
regressions@lists.linux.dev, linux-bcachefs@vger.kernel.org,
linux-hardening@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
ardb@kernel.org, ojeda@kernel.org
Subject: Re: [REGRESSION][BISECTED] erroneous buffer overflow detected in bch2_xattr_validate
Date: Thu, 1 May 2025 11:10:43 -0700 [thread overview]
Message-ID: <202505011109.046221D857@keescook> (raw)
In-Reply-To: <aBO2XVSisMXtU8nD@archlinux>
On Thu, May 01, 2025 at 07:58:53PM +0200, Jan Hendrik Farr wrote:
> So let's say you have a simple struct like so:
>
> struct foo{
> int val_len;
> char val[] __counted_by(val_len);
> }
>
> If val_len is 10 then foo->val[10] will be considered out of bounds.
> Even if you did a malloc for enough space.
Correct. The "counted_by" attribute takes precedence over the "alloc_size"
attribute (which is also generally limited only to the function-scope
where the allocation takes place).
--
Kees Cook
next prev parent reply other threads:[~2025-05-01 18:10 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-26 15:14 [REGRESSION][BISECTED] erroneous buffer overflow detected in bch2_xattr_validate Jan Hendrik Farr
2024-09-26 15:28 ` Thorsten Blum
2024-09-26 16:09 ` Thorsten Blum
2024-09-26 16:37 ` Jan Hendrik Farr
2024-09-26 17:01 ` Jan Hendrik Farr
2024-09-26 17:45 ` Jan Hendrik Farr
2024-09-26 19:58 ` Ard Biesheuvel
2024-09-26 22:18 ` Bill Wendling
2024-09-27 1:30 ` Bill Wendling
2024-09-27 3:41 ` Jan Hendrik Farr
2024-09-28 20:50 ` Kees Cook
2024-09-28 23:33 ` Jan Hendrik Farr
2024-09-29 19:59 ` Jan Hendrik Farr
2024-09-28 17:36 ` Jan Hendrik Farr
2024-09-28 17:49 ` Jan Hendrik Farr
2024-09-28 20:34 ` Kees Cook
2024-10-02 9:18 ` Thorsten Blum
2024-10-03 11:33 ` Jan Hendrik Farr
2024-10-03 13:07 ` Thorsten Blum
2024-10-03 13:12 ` Jan Hendrik Farr
2024-10-03 15:02 ` Thorsten Blum
2024-10-03 15:22 ` Jan Hendrik Farr
2024-10-03 15:30 ` Thorsten Blum
2024-10-03 15:35 ` Jan Hendrik Farr
2024-10-03 15:43 ` Thorsten Blum
2024-10-03 16:32 ` Jan Hendrik Farr
2024-10-03 15:17 ` Jan Hendrik Farr
2024-10-03 21:28 ` Kees Cook
2024-10-03 21:48 ` Jan Hendrik Farr
2024-10-04 17:13 ` Kees Cook
2024-10-07 3:56 ` Jan Hendrik Farr
2024-10-07 15:10 ` Jan Hendrik Farr
2024-10-16 21:13 ` Kees Cook
2024-10-16 23:41 ` Bill Wendling
2024-10-17 0:09 ` Bill Wendling
2024-10-17 3:04 ` Jan Hendrik Farr
2024-10-17 16:55 ` Nathan Chancellor
2024-10-17 17:39 ` Miguel Ojeda
2024-10-17 18:55 ` Nathan Chancellor
2024-10-18 11:52 ` Miguel Ojeda
2024-10-21 1:33 ` Jan Hendrik Farr
2024-10-21 6:04 ` Miguel Ojeda
2024-10-21 17:01 ` Jan Hendrik Farr
2024-10-21 19:25 ` Nathan Chancellor
2024-10-24 13:16 ` Jan Hendrik Farr
2024-10-25 1:15 ` Nathan Chancellor
2024-10-25 8:10 ` Miguel Ojeda
2024-10-25 15:27 ` Jan Hendrik Farr
2025-05-01 14:30 ` Alan Huang
2025-05-01 16:45 ` Jan Hendrik Farr
2025-05-01 17:22 ` Jan Hendrik Farr
2025-05-01 17:28 ` Alan Huang
2025-05-01 17:58 ` Jan Hendrik Farr
2025-05-01 18:10 ` Kees Cook [this message]
2025-05-01 18:18 ` Alan Huang
2024-10-17 0:41 ` Jan Hendrik Farr
2024-10-14 21:39 ` Bill Wendling
2024-10-16 1:22 ` Bill Wendling
2024-10-16 2:18 ` Jan Hendrik Farr
2024-10-16 20:43 ` Kees Cook
2024-10-03 21:23 ` Kees Cook
2024-10-03 22:05 ` Jan Hendrik Farr
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