CVE-2026-98900

Published: October 28, 2026Last modified: October 28, 2026

Description

In the Linux kernel, the following vulnerability has been resolved: xen/gntalloc: validate grant count before allocation gntalloc_ioctl_alloc() allocates the grant-id array before checking whether the requested count fits within the global grant limit. Counts above that limit cannot succeed, so reject them before the user-controlled allocation reaches kcalloc(). Use a subtraction-based check while holding gref_mutex so adding the requested count cannot wrap. Also cast the count before advancing the per-file index so the page-size multiplication is performed in 64-bit arithmetic.

Status

References

• https://git.kernel.org/stable/c/2299822f3f466b5dcad2377bf63986199f881a6b
• https://git.kernel.org/stable/c/231542f4e43cf9837cb520664545e85fbe666b7b
• https://git.kernel.org/stable/c/641de086a05f349de7fc548612432bc2fed721ca
• https://git.kernel.org/stable/c/71a0cf87e19fb35c4292ca88985e376e613c900a
• https://git.kernel.org/stable/c/720554c04acba80018ded069d3e0984bebaee891
• https://git.kernel.org/stable/c/84d5727cef8eb9c8a28210ad248f1c70b223b065
• https://git.kernel.org/stable/c/e2806390aa1c4d5b3f7a68f10a56ae12c71c00d8