CVE-2026-89751 - x86/tdx: Fix off-by-one in port I/O handling
Brief
CVE ID : CVE-2026-89751
Published : Sept. 11, 2026, 8:20 p. m.
- 32 minutes ago
Description : In the Linux kernel, the following vulnerability has been resolved:
x86/tdx: Fix off-by-one in port I/O handling
handle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use:
u64 mask = GENMASK(BITS_PER_BYTE * size, 0);
GENMASK(h, l) includes bit h. For size=1 (INB), this produces GENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8 bits). The mask is one bit too wide for all I/O sizes.