CVE-2024-44947 PoC — fuse: Initialize beyond-EOF page contents before setting uptodate

Title:fuse: Initialize beyond-EOF page contents before setting uptodate (CVE-2024-44947)
Description:In the Linux kernel, the following vulnerability has been resolved: fuse: Initialize beyond-EOF page contents before setting uptodate fuse_notify_store(), unlike fuse_do_readpage(), does not enable page zeroing (because it can be used to change partial page contents). So fuse_notify_store() must be more careful to fully initialize page contents (including parts of the page that are beyond end-of-file) before marking the page uptodate. The current code can leave beyond-EOF page contents uninitialized, which makes these uninitialized page contents visible to userspace via mmap(). This is an information leak, but only affects systems which do not enable init-on-alloc (via CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y or the corresponding kernel command line parameter).

 [4.0K]  /data/pocs/6f5b737ab40e4574c49606f952fe0ec48491e4e4
├── [4.1K]  fuse_poc_advanced.c
└── [2.2K]  readme.md

0 directories, 2 files