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| 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 /kernel | |
| parent | 8fde12ca79aff9b5ba951fce1a2641901b8d8e64 (diff) | |
| download | linux-15fab63e1e57be9fdb5eec1bbc5916e9825e9acb.tar.gz | |
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 'kernel')
| -rw-r--r-- | kernel/trace/trace.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c4238b441624..0f300d488c9f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6835,12 +6835,16 @@ static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, buf->private = 0; } -static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, +static bool buffer_pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { struct buffer_ref *ref = (struct buffer_ref *)buf->private; + if (ref->ref > INT_MAX/2) + return false; + ref->ref++; + return true; } /* Pipe buffer operations for a buffer. */ |