From: Alexander Potapenko <glider@xxxxxxxxxx> Subject: fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info() 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. Link: http://lkml.kernel.org/r/20200419100848.63472-1-glider@xxxxxxxxxx Link: https://github.com/google/kmsan/issues/76 Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> Reported-by: sam <sunhaoyl@xxxxxxxxxxx> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/binfmt_elf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/binfmt_elf.c~fs-binfmt_elfc-allocate-initialized-memory-in-fill_thread_core_info +++ a/fs/binfmt_elf.c @@ -1733,7 +1733,7 @@ static int fill_thread_core_info(struct (!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, _
