vfs/splice: Fix missed checks in new __kernel_write() helper
Commit 06ae43f34bcc ("Don't bother with redoing rw_verify_area() from
default_file_splice_from()") lost the checks to test existence of the
write/aio_write methods. My apologies ;-/
Eventually, we want that in fs/splice.c side of things (no point
repeating it for every buffer, after all), but for now this is the
obvious minimal fix.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/read_write.c b/fs/read_write.c
index f7b5a23..e6ddc8d 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -424,6 +424,9 @@
const char __user *p;
ssize_t ret;
+ if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write))
+ return -EINVAL;
+
old_fs = get_fs();
set_fs(get_ds());
p = (__force const char __user *)buf;