Linux Kernel Xen gntalloc: Grant Count Validation Before Allocation
CVE-2026-98900 Published on October 23, 2026
xen/gntalloc: validate grant count before allocation
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.
Products Associated with CVE-2026-98900
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Affected Versions
Linux:- Version dd3140588d9551235ebc2a0dacdca098e7677573 and below e2806390aa1c4d5b3f7a68f10a56ae12c71c00d8 is affected.
- Version dd3140588d9551235ebc2a0dacdca098e7677573 and below 71a0cf87e19fb35c4292ca88985e376e613c900a is affected.
- Version dd3140588d9551235ebc2a0dacdca098e7677573 and below 641de086a05f349de7fc548612432bc2fed721ca is affected.
- Version dd3140588d9551235ebc2a0dacdca098e7677573 and below 720554c04acba80018ded069d3e0984bebaee891 is affected.
- Version dd3140588d9551235ebc2a0dacdca098e7677573 and below 84d5727cef8eb9c8a28210ad248f1c70b223b065 is affected.
- Version dd3140588d9551235ebc2a0dacdca098e7677573 and below 231542f4e43cf9837cb520664545e85fbe666b7b is affected.
- Version dd3140588d9551235ebc2a0dacdca098e7677573 and below 2299822f3f466b5dcad2377bf63986199f881a6b is affected.
- Version 2.6.39 is affected.
- Before 2.6.39 is unaffected.
- Version 5.10.271, <= 5.10.* is unaffected.
- Version 5.15.222, <= 5.15.* is unaffected.
- Version 6.1.189, <= 6.1.* is unaffected.
- Version 6.6.158, <= 6.6.* is unaffected.
- Version 6.12.111, <= 6.12.* is unaffected.
- Version 6.18.53, <= 6.18.* is unaffected.
- Version 7.2, <= * is unaffected.