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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 /fs/fuse | |
| parent | 8fde12ca79aff9b5ba951fce1a2641901b8d8e64 (diff) | |
| download | linux-15fab63e1e57be9fdb5eec1bbc5916e9825e9acb.tar.gz linux-15fab63e1e57be9fdb5eec1bbc5916e9825e9acb.tar.bz2 linux-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/fuse')
| -rw-r--r-- | fs/fuse/dev.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 809c0f2f9942..64f4de983468 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -2034,10 +2034,8 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len; ret = -EINVAL; - if (rem < len) { - pipe_unlock(pipe); - goto out; - } + if (rem < len) + goto out_free; rem = len; while (rem) { @@ -2055,7 +2053,9 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); pipe->nrbufs--; } else { - pipe_buf_get(pipe, ibuf); + if (!pipe_buf_get(pipe, ibuf)) + goto out_free; + *obuf = *ibuf; obuf->flags &= ~PIPE_BUF_FLAG_GIFT; obuf->len = rem; @@ -2078,11 +2078,11 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, ret = fuse_dev_do_write(fud, &cs, len); pipe_lock(pipe); +out_free: for (idx = 0; idx < nbuf; idx++) pipe_buf_release(pipe, &bufs[idx]); pipe_unlock(pipe); -out: kvfree(bufs); return ret; } |