diff options
| author |   Matthew Wilcox <willy@infradead.org> | 2019-04-05 14:02:10 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-04-14 10:00:04 -0700 |
| commit | 15fab63e1e57be9fdb5eec1bbc5916e9825e9acb (patch) | |
| tree | 1353971310401012cf4b108a375e525065d8bec0 /fs/splice.c | |
| parent | mm: prevent get_user_pages() from overflowing page refcount (diff) | |
| download | linux-dev-15fab63e1e57be9fdb5eec1bbc5916e9825e9acb.tar.xz linux-dev-15fab63e1e57be9fdb5eec1bbc5916e9825e9acb.zip | |
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>
Diffstat (limited to 'fs/splice.c')
| -rw-r--r-- | fs/splice.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/splice.c b/fs/splice.c index de2ede048473..f30af82b850d 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1588,7 +1588,11 @@ retry: * Get a reference to this pipe buffer, * so we can copy the contents over. */ - pipe_buf_get(ipipe, ibuf); + if (!pipe_buf_get(ipipe, ibuf)) { + if (ret == 0) + ret = -EFAULT; + break; + } *obuf = *ibuf; /* @@ -1660,7 +1664,11 @@ static int link_pipe(struct pipe_inode_info *ipipe, * Get a reference to this pipe buffer, * so we can copy the contents over. */ - pipe_buf_get(ipipe, ibuf); + if (!pipe_buf_get(ipipe, ibuf)) { + if (ret == 0) + ret = -EFAULT; + break; + } obuf = opipe->bufs + nbuf; *obuf = *ibuf; |