Vulnerability Database

319,703

Total vulnerabilities in the database

CVE-2025-39941

In the Linux kernel, the following vulnerability has been resolved:

zram: fix slot write race condition

Parallel concurrent writes to the same zram index result in leaked zsmalloc handles. Schematically we can have something like this:

CPU0 CPU1 zram_slot_lock() zs_free(handle) zram_slot_lock() zram_slot_lock() zs_free(handle) zram_slot_lock()

compress compress handle = zs_malloc() handle = zs_malloc() zram_slot_lock zram_set_handle(handle) zram_slot_lock zram_slot_lock zram_set_handle(handle) zram_slot_lock

Either CPU0 or CPU1 zsmalloc handle will leak because zs_free() is done too early. In fact, we need to reset zram entry right before we set its new handle, all under the same slot lock scope.

  • Published: Oct 4, 2025
  • Updated: Jan 24, 2026
  • CVE: CVE-2025-39941
  • Severity: Low
  • Exploit:

CVSS v3:

  • Severity: Low
  • Score: 4.7
  • AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

CWEs:

Software From Fixed in
linux / linux_kernel 6.14 6.16.9
linux / linux_kernel 6.17-rc1 6.17-rc1.x
linux / linux_kernel 6.17-rc2 6.17-rc2.x
linux / linux_kernel 6.17-rc3 6.17-rc3.x
linux / linux_kernel 6.17-rc4 6.17-rc4.x
linux / linux_kernel 6.17-rc5 6.17-rc5.x
linux / linux_kernel 6.17-rc6 6.17-rc6.x