fs: prevent page refcount overflow in pipe_buf_get
authorMatthew Wilcox <willy@infradead.org>
Fri, 5 Apr 2019 21:02:10 +0000 (14:02 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sun, 14 Apr 2019 17:00:04 +0000 (10:00 -0700)
commit15fab63e1e57be9fdb5eec1bbc5916e9825e9acb
tree1353971310401012cf4b108a375e525065d8bec0
parent8fde12ca79aff9b5ba951fce1a2641901b8d8e64
fs: prevent page refcount overflow in pipe_buf_get

Change pipe_buf_get() to return a bool indicating whether it succeeded
in raising the refcount of the page (if the thing in the pipe is a page).
This removes another mechanism for overflowing the page refcount.  All
callers converted to handle a failure.

Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/fuse/dev.c
fs/pipe.c
fs/splice.c
include/linux/pipe_fs_i.h
kernel/trace/trace.c