linux-hardening - Re: [PATCH] pstore: ram_core: fix possible overflow in persistent_ram_init

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Sat,  2 Dec 2023 12:47:23 -0800
From: Kees Cook <keescook@...omium.org>
To: Tony Luck <tony.luck@...el.com>,
	"Guilherme G. Piccoli" <gpiccoli@...lia.com>,
	linux-hardening@...r.kernel.org,
	Sergey Shtylyov <s.shtylyov@....ru>
Cc: Kees Cook <keescook@...omium.org>
Subject: Re: [PATCH] pstore: ram_core: fix possible overflow in persistent_ram_init_ecc()

On Sun, 05 Nov 2023 23:29:36 +0300, Sergey Shtylyov wrote:
> In persistent_ram_init_ecc(), on 64-bit arches DIV_ROUND_UP() will return
> 64-bit value since persistent_ram_zone::buffer_size has type size_t which
> is derived from the 64-bit *unsigned long*, while the ecc_blocks variable
> this value gets assigned to has (always 32-bit) *int* type.  Even if that
> value fits into *int* type, an overflow is still possible when calculating
> the size_t typed ecc_total variable further below since there's no cast to
> any 64-bit type before multiplication.  Declaring the ecc_blocks variable
> as *unsigned long* should fix this mess...
> 
> [...]

I changed this from unsigned long to size_t, which will do the same thing.

Applied to for-linus/pstore, thanks!

[1/1] pstore: ram_core: fix possible overflow in persistent_ram_init_ecc()
      https://git.kernel.org/kees/c/c92116e01d32

Take care,

-- 
Kees Cook