linux-kernel - regression from your recent change to x86's copy_user_handle

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-next>] [day] [month] [year] [list]

Message-Id: <55375CC30200007800074A08@mail.emea.novell.com>
Date:	Wed, 22 Apr 2015 07:33:07 +0100
From:	"Jan Beulich" <JBeulich@...e.com>
To:	"Linus Torvalds" <torvalds@...ux-foundation.org>
Cc:	<linux-kernel@...r.kernel.org>
Subject: regression from your recent change to x86's
 copy_user_handle_tail()

Linus,

while the description of commit cae2a173fe certainly makes sense, the
change itself ignores the __probe_kernel_write() code path, for which
the destination address is expected to be in kernel space but accesses
may still fault. I.e. the use of plain memset() causes
__probe_kernel_write() to oops rather than return an error. Shouldn't
the "(unsigned long)to >= TASK_SIZE_MAX" be relaxed to take the
effect of set_fs() into account?

Thanks, Jan

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/