CVE-2026-53185

A flaw was found in the Linux kernel, specifically within the zram module. This vulnerability is a use-after-free error, where the system attempts to use a piece of memory after it has been freed. This occurs when the zram_bvec_write_partial() function allows an asynchronous read to write into a page that has already been deallocated. Such a flaw can lead to system instability, causing crashes, or in some scenarios, could be exploited by a local attacker to escalate privileges or execute arbitrary code.

A use-after-free write can occur in zram_bvec_write_partial() when zram_read_page() is called with a parent bio and selects the asynchronous backing device read path for ZRAM_WB slots. The function can return while the read bio is still in flight, after which the caller updates the temporary page, writes it back, and frees it. The pending asynchronous read may then complete into the freed page, causing kernel memory corruption. For the CVSS the PR:L is used because triggering can be possible from a local user context once zram writeback is configured, for example through swap or block I/O activity, even though initial writeback setup is usually administrative.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent module zram from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.