In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map use-after-free when adding pages to compressed bio At add_ra_bio_pages() we are accessing the extent map to calculate 'add_size' after we dropped our reference on the extent map, resulting in a use-after-free. Fix this by computing 'add_size' before dropping our extent map reference.
https://git.kernel.org/stable/c/c205565e0f2f439f278a4a94ee97b67ef7b56ae8
https://git.kernel.org/stable/c/c1cc3326e27b0bd7a2806b40bc48e49afaf951e7
https://git.kernel.org/stable/c/b7859ff398b6b656e1689daa860eb34837b4bb89
https://git.kernel.org/stable/c/8e7860543a94784d744c7ce34b78a2e11beefa5c