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From: Andrew Morton <akpm@linux-foundation.org>
To: Martin Weiss <martin.githubacc@gmail.com>
Cc: linux-kernel@vger.kernel.org,
	Martin Weiss <Martin.weiss2410@gmail.com>,
	Jason Baron <jbaron@akamai.com>,
	Jim Cromie <jim.cromie@gmail.com>
Subject: Re: [PATCH 1/4] lib/dynamic_debug: add NULL check after kstrdup
Date: Mon, 29 Jun 2026 16:51:46 -0700	[thread overview]
Message-ID: <20260629165146.f8cce11cdd13682d482c0319@linux-foundation.org> (raw)
In-Reply-To: <20260629093056.591498-1-Martin.weiss2410@gmail.com>

On Mon, 29 Jun 2026 16:30:51 +0700 Martin Weiss <martin.githubacc@gmail.com> wrote:

> kstrdup(saved_command_line, GFP_KERNEL) may return NULL under memory
> pressure. Add a check to avoid NULL pointer dereference during boot-time
> dynamic debug parameter parsing.
> 

Thanks.

> --- a/lib/dynamic_debug.c
> +++ b/lib/dynamic_debug.c
> @@ -1479,6 +1479,8 @@ static int __init dynamic_debug_init(void)
>  	 * slightly noisy if verbose, but harmless.
>  	 */
>  	cmdline = kstrdup(saved_command_line, GFP_KERNEL);
> +	if (!cmdline)
> +		return 0; /* prevents a boot-time NULL deref */
>  	parse_args("dyndbg params", cmdline, NULL,
>  		   0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb);
>  	kfree(cmdline);

We conventionally assume that memory allocations at __init time cannot
fail.  Sashiko explains why ;)

	https://sashiko.dev/#/patchset/20260629093056.591498-1-Martin.weiss2410@gmail.com

      parent reply	other threads:[~2026-06-29 23:51 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-29  9:30 Martin Weiss
2026-06-29  9:30 ` [PATCH 2/4] selftests: filesystems: fix spelling mistake in statmount test Martin Weiss
2026-06-29  9:30 ` [PATCH 3/4] selftests: powerpc: fix spelling mistake Martin Weiss
2026-06-29  9:30 ` [PATCH 4/4] tools/build: fix spelling mistake in documentation Martin Weiss
2026-06-29 23:51 ` Andrew Morton [this message]

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