fs/ntfs3: Fix slab-out-of-bounds in r_page

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Fix slab-out-of-bounds in r_page When PAGE_SIZE is 64K, if read_log_page is called by log_read_rst for the first time, the size of *buffer would be equal to DefaultLogPageSize(4K).But for *buffer operations like memcpy, if the memory area size(n) which being assigned to buffer is larger than 4K (log->page_size(64K) or bytes(64K-page_off)), it will cause an out of boundary error. Call trace: [...] kasan_report+0x44/0x130 check_memory_region+0xf8/0x1a0 memcpy+0xc8/0x100 ntfs_read_run_nb+0x20c/0x460 read_log_page+0xd0/0x1f4 log_read_rst+0x110/0x75c log_replay+0x1e8/0x4aa0 ntfs_loadlog_and_replay+0x290/0x2d0 ntfs_fill_super+0x508/0xec0 get_tree_bdev+0x1fc/0x34c [...] Fix this by setting variable r_page to NULL in log_read_rst.

References

• https://git.kernel.org/stable/c/ed686e7a26dd19ae6b46bb662f735acfa88ff7bc
• https://git.kernel.org/stable/c/bf86a640a34947d92062996e1a75b9cd9d83dd19
• https://git.kernel.org/stable/c/6d076293e5bffdf897ea5f975669206e09beed6a
• https://git.kernel.org/stable/c/ecfbd57cf9c5ca225184ae266ce44ae473792132