Linux Kernel up to 7.2.7/7.3-rc3 dma-buf calc_sg_nents integer overflow

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 7.2.7/7.3-rc3. This affects the function calc_sg_nents of the component dma-buf. Performing a manipulation results in integer overflow. This vulnerability was named CVE-2026-98242. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2.7/7.3-rc3. It has been classified as very critical. This affects the function calc_sg_nents of the component dma-buf. The manipulation with an unknown input leads to a integer overflow vulnerability. CWE is classifying the issue as CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: dma-buf: Fix silent overflow for phys vec to sgt In case MMIO size is bigger than 4G and peer2peer DMA goes through host bridge, we trigger a code path that assigns the total linked IOVA (which is greater than 4G) to mapped_len. Previously, `mapped_len` was declared as 32-bit `unsigned int`. When accumulating `size_t` lengths, this leads to a silent wrap-around. This truncation causes truncated lengths to be passed to functions like `fill_sg_entry()`. Fix this by changing `mapped_len` to `size_t` (64-bit). While at it, fix similar potential overflow issues in `calc_sg_nents` by using `check_add_overflow()` for `nents` and using `unsigned int` for the loop iterator in `fill_sg_entry` to match.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-98242 since 09/25/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 10/06/2026).

Upgrading to version 7.2.8 or 7.3-rc4 eliminates this vulnerability. Applying the patch 6b98fd7106d4e486f432664893dcd4d6fa3a9693/b344ca94e8cc85796f16ea25e2e5a8e0303fe813 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.2.7
• 7.3-rc1
• 7.3-rc2
• 7.3-rc3

License

• open-source

Website

• Vendor: https://www.kernel.org/

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