Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
md: use kzalloc() when bitmap is disabled
commit b6878d9e03043695dbf3fa1caa6dfc09db225b16 upstream. In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a mdu_bitmap_file_t called "file". 5769 file = kmalloc(sizeof(*file), GFP_NOIO); 5770 if (!file) 5771 return -ENOMEM; This structure is copied to user space at the end of the function. 5786 if (err == 0 && 5787 copy_to_user(arg, file, sizeof(*file))) 5788 err = -EFAULT But if bitmap is disabled only the first byte of "file" is initialized with zero, so it's possible to read some bytes (up to 4095) of kernel space memory from user space. This is an information leak. 5775 /* bitmap disabled, zero the first byte and copy out */ 5776 if (!mddev->bitmap_info.file) 5777 file->pathname[0] = '\0'; Change-Id: I7cd2a3c7fad2e2cb9edb8b4eff2af8a3a8f40149 Signed-off-by: Benjamin Randazzo <[email protected]> Signed-off-by: NeilBrown <[email protected]> [lizf: Backported to 3.4: fix both branches] Signed-off-by: Zefan Li <[email protected]>
- Loading branch information