Commit a02c130e authored May 27, 2020 by Alexander Potapenko Committed by Greg Kroah-Hartman Jun 03, 2020

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.

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>

parent de482c44

fs/binfmt_elf.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1731,7 +1731,7 @@ 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_size(t->task, regset);
		void *data = kmalloc(size, GFP_KERNEL);
		void *data = kzalloc(size, GFP_KERNEL);
		if (unlikely(!data))
		return 0;
		ret = regset->get(t->task, regset,