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From: Kees Cook <keescook@chromium.org>
To: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Justin Stitt <justinstitt@google.com>,
	Charles Bertsch <cbertsch@cox.net>,
	linux-scsi@vger.kernel.org, MPT-FusionLinux.pdl@broadcom.com
Subject: Re: startup BUG at lib/string_helpers.c from scsi fusion mptsas
Date: Thu, 4 Apr 2024 16:57:41 -0700	[thread overview]
Message-ID: <202404041646.7B813E9AD@keescook> (raw)
In-Reply-To: <784db8a20a3ddeb6c0498f2b31719e5198da6581.camel@HansenPartnership.com>

On Thu, Apr 04, 2024 at 06:33:38PM -0400, James Bottomley wrote:
> But additionally this is a common pattern in SCSI: using strncpy to
> zero terminate fields that may be unterminated in the exchange protocol
> so we can send them to sysfs or otherwise treat them as strings.  That
> means we might have this problem in other drivers you've converted ...

This use of copying a maybe-NUL-terminated source is yet another weird
corner-case of strncpy(). :(

But it's also easy to check for this "strncpy used with size
matching source size but destination is bigger" case with some build
instrumentation. I'll see what it turns up.

-- 
Kees Cook

  parent reply	other threads:[~2024-04-04 23:57 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-01 22:43 startup BUG at lib/string_helpers.c from scsi fusion mptsas Charles Bertsch
2024-04-03 23:20 ` Bart Van Assche
2024-04-04 19:58   ` Justin Stitt
2024-04-04 21:38 ` Justin Stitt
2024-04-04 21:53   ` James Bottomley
2024-04-04 22:04     ` Justin Stitt
2024-04-04 22:29       ` James Bottomley
2024-04-04 22:33         ` James Bottomley
2024-04-04 22:43           ` Martin K. Petersen
2024-04-04 22:47           ` Justin Stitt
2024-04-04 23:39             ` Kees Cook
2024-04-05  0:10               ` Justin Stitt
2024-04-05  0:12                 ` Justin Stitt
2024-04-04 23:57           ` Kees Cook [this message]
2024-04-06 20:42   ` Charles Bertsch
2024-04-08 19:59     ` Justin Stitt
2024-04-08 23:19       ` Kees Cook
2024-04-10 20:51         ` Justin Stitt
2024-04-10 21:14           ` Charles Bertsch

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