CVE-2026-89765

Summary

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

timers/itimer: Zero-init old itimerval before copy to userspace

On native sparc64, struct __kernel_old_timeval contains a four-byte hole after tv_usec because tv_sec is 64-bit while __kernel_suseconds_t is 32-bit. put_itimerval() fills only the named fields in a stack-allocated __kernel_old_itimerval and copies the entire object to userspace, so getitimer() can expose the two padding holes.

Zero-initialize the aggregate before assigning the fields so implicit padding is deterministic before it crosses the user/kernel boundary.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 4c66719dd1e4023c5e3f7d050f1bbefec3dfbeb4affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 2bf5e8f7c9bf4ad3be343a9a6e3e50a34264d25eaffected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 00ef529a5402f41eb1d227916437e237450719f9affected
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 18c7d85864e554adc8fad1e8d2e9d2cb6c3911c8affected
LinuxLinux0 < 6.12.109affected
LinuxLinux0 < 6.18.50affected
LinuxLinux0 < 7.2.4affected
LinuxLinux6.12.109 <= 6.12.*unaffected
LinuxLinux6.18.50 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References