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

glider
2020-04-19T10:08:58Z

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>

---

Note: Reported-by: line is subject to change
---
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 13f25e241ac4..25d489bc9453 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1733,7 +1733,7 @@ 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,
--
2.26.1.301.g55bc3eb7cb9-goog