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authorTodd Kjos <tkjos@android.com>2019-12-13 23:25:31 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-12-14 11:10:47 +0300
commit16981742717b04644a41052570fb502682a315d2 (patch)
tree81e6f0d2bf4db7382e7aaf6064ffd0e481dca03b /drivers/android/binder.c
parent3e42fe5c73108a6e68c98bc0df937888e35af97f (diff)
downloadlinux-16981742717b04644a41052570fb502682a315d2.tar.xz
binder: fix incorrect calculation for num_valid
For BINDER_TYPE_PTR and BINDER_TYPE_FDA transactions, the num_valid local was calculated incorrectly causing the range check in binder_validate_ptr() to miss out-of-bounds offsets. Fixes: bde4a19fc04f ("binder: use userspace pointer as base of buffer space") Signed-off-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191213202531.55010-1-tkjos@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/android/binder.c')
-rw-r--r--drivers/android/binder.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index e9bc9fcc7ea5..b2dad43dbf82 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -3310,7 +3310,7 @@ static void binder_transaction(struct binder_proc *proc,
binder_size_t parent_offset;
struct binder_fd_array_object *fda =
to_binder_fd_array_object(hdr);
- size_t num_valid = (buffer_offset - off_start_offset) *
+ size_t num_valid = (buffer_offset - off_start_offset) /
sizeof(binder_size_t);
struct binder_buffer_object *parent =
binder_validate_ptr(target_proc, t->buffer,
@@ -3384,7 +3384,7 @@ static void binder_transaction(struct binder_proc *proc,
t->buffer->user_data + sg_buf_offset;
sg_buf_offset += ALIGN(bp->length, sizeof(u64));
- num_valid = (buffer_offset - off_start_offset) *
+ num_valid = (buffer_offset - off_start_offset) /
sizeof(binder_size_t);
ret = binder_fixup_parent(t, thread, bp,
off_start_offset,