Commit a2477b0e authored by Andrey Ryabinin's avatar Andrey Ryabinin Committed by Miklos Szeredi

fuse: Don't access pipe->buffers without pipe_lock()

fuse_dev_splice_write() reads pipe->buffers to determine the size of
'bufs' array before taking the pipe_lock(). This is not safe as
another thread might change the 'pipe->buffers' between the allocation
and taking the pipe_lock(). So we end up with too small 'bufs' array.

Move the bufs allocations inside pipe_lock()/pipe_unlock() to fix this.

Fixes: dd3bb14f ("fuse: support splice() writing to fuse device")
Signed-off-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Cc: <stable@vger.kernel.org> # v2.6.35
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 63576c13
......@@ -1955,12 +1955,15 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
if (!fud)
return -EPERM;
pipe_lock(pipe);
bufs = kmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
GFP_KERNEL);
if (!bufs)
if (!bufs) {
pipe_unlock(pipe);
return -ENOMEM;
}
pipe_lock(pipe);
nbuf = 0;
rem = 0;
for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
......
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