From: Alexander Potapenko <glider@google.com>
Date: Thu, 28 May 2020 05:20:52 +0000 (-0700)
Subject: fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()
X-Git-Tag: MMI-QSAS30.62-33-12~1
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=cb691c5aacf1b6dab30bc90a13588e14975c452c;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()

[ Upstream commit 1d605416fb7175e1adf094251466caa52093b413 ]

KMSAN reported uninitialized data being written to disk when dumping
core.  As a result, several kilobytes of kmalloc memory may be written
to the core file and then read by a non-privileged user.

Mot-CRs-fixed: (CR)
CVE-Fixed: CVE-2020-10732
Bug: 170658976

Change-Id: I4fee1e083969bdb872a725c4ded238ef29d1d7b1
Reported-by: sam <sunhaoyl@outlook.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200419100848.63472-1-glider@google.com
Link: https://github.com/google/kmsan/issues/76
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jignesh Patel <jignesh@motorola.com>
Reviewed-on: https://gerrit.mot.com/1828648
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key
---

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 469666df91da..f7dbdb5b635b 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1728,7 +1728,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
 		    (!regset->active || regset->active(t->task, regset) > 0)) {
 			int ret;
 			size_t size = regset->n * regset->size;
-			void *data = kmalloc(size, GFP_KERNEL);
+			void *data = kzalloc(size, GFP_KERNEL);
 			if (unlikely(!data))
 				return 0;
 			ret = regset->get(t->task, regset,