[RHEL8,COMMIT] ms/fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()

Submitted by Konstantin Khorenko on Sept. 30, 2020, 2:25 p.m.


Message ID 202009301425.08UEPbA7067426@finist-co8.sw.ru
State New
Series "ms/fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()"
Headers show

Commit Message

Konstantin Khorenko Sept. 30, 2020, 2:25 p.m.
The commit is pushed to "branch-rh8-4.18.0-193.6.3.vz8.4.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-193.6.3.vz8.4.9
commit 7d9c95d8798f29365b9a317c22d58e2749186337
Author: Alexander Potapenko <glider@google.com>
Date:   Wed Sep 30 17:25:37 2020 +0300

    ms/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.
    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>
    Commit 1d605416fb7175e1adf094251466caa52093b413 in the mainline
    kernel. Re-diffed for vz8.4.x, context change only.
    Signed-off-by: Evgenii Shatokhin <eshatokhin@virtuozzo.com>
 fs/binfmt_elf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index dd3e56edd2f3..c9fdad31fb37 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1766,7 +1766,7 @@  static int fill_thread_core_info(struct elf_thread_core_info *t,
 		    (!regset->active || regset->active(t->task, regset))) {
 			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,