From a02c130efbbce91af1e9dd99a5a381dd43494e15 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Wed, 27 May 2020 22:20:52 -0700 Subject: [PATCH] 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 Signed-off-by: Alexander Potapenko Signed-off-by: Andrew Morton Acked-by: Kees Cook Cc: Al Viro Cc: Alexey Dobriyan Cc: 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 Signed-off-by: Sasha Levin --- fs/binfmt_elf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index c5642bcb6b46..7ce3cfd965d2 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -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,