Synopsis
The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.
Description
The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.
- In the Linux kernel, the following vulnerability has been resolved: mm: fix unexpected zeroed page mapping with zram swap Two processes under CLONE_VM cloning, user process can be corrupted by seeing zeroed page unexpectedly. CPU A CPU B do_swap_page do_swap_page SWP_SYNCHRONOUS_IO path SWP_SYNCHRONOUS_IO path swap_readpage valid data swap_slot_free_notify delete zram entry swap_readpage zeroed(invalid) data pte_lock map the *zero data* to userspace pte_unlock pte_lock if (!pte_same) goto out_nomap; pte_unlock return and next refault will read zeroed data The swap_slot_free_notify is bogus for CLONE_VM case since it doesn't increase the refcount of swap slot at copy_mm so it couldn't catch up whether it's safe or not to discard data from backing device. In the case, only the lock it could rely on to synchronize swap slot freeing is page table lock. Thus, this patch gets rid of the swap_slot_free_notify function. With this patch, CPU A will see correct data. CPU A CPU B do_swap_page do_swap_page SWP_SYNCHRONOUS_IO path SWP_SYNCHRONOUS_IO path swap_readpage original data pte_lock map the original data swap_free swap_range_free bd_disk->fops->swap_slot_free_notify swap_readpage read zeroed data pte_unlock pte_lock if (!pte_same) goto out_nomap; pte_unlock return on next refault will see mapped data by CPU B The concern of the patch would increase memory consumption since it could keep wasted memory with compressed form in zram as well as uncompressed form in address space. However, most of cases of zram uses no readahead and do_swap_page is followed by swap_free so it will free the compressed form from in zram quickly.
(CVE-2022-49052)
Note that Nessus relies on the presence of the package as reported by the vendor.
Solution
There is no known solution at this time.
Plugin Details
File Name: unpatched_CVE_2022_49052.nasl
Agent: unix
Supported Sensors: Nessus Agent, Nessus
Risk Information
Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched
Exploit Ease: No known exploits are available
Vulnerability Publication Date: 2/26/2025