From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: + =?US-ASCII?Q?kernel-sysctl-ignore-out-of-range-taint-bits-introduced-via?= =?US-ASCII?Q?-kerneltainted.patch?= added to -mm tree Date: Wed, 13 May 2020 13:56:12 -0700 Message-ID: <20200513205612.Yo0fgCLIb%akpm@linux-foundation.org> References: <20200507183509.c5ef146c5aaeb118a25a39a8@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Return-path: Received: from mail.kernel.org ([198.145.29.99]:58314 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725943AbgEMU4P (ORCPT ); Wed, 13 May 2020 16:56:15 -0400 In-Reply-To: <20200507183509.c5ef146c5aaeb118a25a39a8@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: aquini@redhat.com, keescook@chromium.org, mcgrof@kernel.org, mm-commits@vger.kernel.org, tytso@mit.edu, yzaikin@google.com The patch titled Subject: kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.tainted has been added to the -mm tree. Its filename is kernel-sysctl-ignore-out-of-range-taint-bits-introduced-via-kerneltainted.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/kernel-sysctl-ignore-out-of-range-taint-bits-introduced-via-kerneltainted.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/kernel-sysctl-ignore-out-of-range-taint-bits-introduced-via-kerneltainted.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Rafael Aquini Subject: kernel/sysctl.c: ignore out-of-range taint bits introduced via kernel.tainted Users with SYS_ADMIN capability can add arbitrary taint flags to the running kernel by writing to /proc/sys/kernel/tainted or issuing the command 'sysctl -w kernel.tainted=...'. This interface, however, is open for any integer value and this might cause an invalid set of flags being committed to the tainted_mask bitset. This patch introduces a simple way for proc_taint() to ignore any eventual invalid bit coming from the user input before committing those bits to the kernel tainted_mask. Link: http://lkml.kernel.org/r/20200512223946.888020-1-aquini@redhat.com Signed-off-by: Rafael Aquini Reviewed-by: Luis Chamberlain Cc: Kees Cook Cc: Iurii Zaikin Cc: "Theodore Ts'o" Signed-off-by: Andrew Morton --- kernel/sysctl.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/kernel/sysctl.c~kernel-sysctl-ignore-out-of-range-taint-bits-introduced-via-kerneltainted +++ a/kernel/sysctl.c @@ -870,10 +870,9 @@ static int proc_taint(struct ctl_table * * to everyone's atomic.h for this */ int i; - for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) { - if ((tmptaint >> i) & 1) + for (i = 0; i < TAINT_FLAGS_COUNT; i++) + if ((1UL << i) & tmptaint) add_taint(i, LOCKDEP_STILL_OK); - } } return err; _ Patches currently in -mm which might be from aquini@redhat.com are mm-slub-add-panic_on_error-to-the-debug-facilities.patch kernel-sysctl-ignore-out-of-range-taint-bits-introduced-via-kerneltainted.patch