CVE-2025-21736 Information

Description

In the Linux kernel the following vulnerability has been resolved:

nilfs2: fix possible int overflows in nilfs_fiemap()

Since nilfs_bmap_lookup_contig() in nilfs_fiemap() calculates its result by being prepared to go through potentially maxblocks == INT_MAX blocks the value in n may experience an overflow caused by left shift of blkbits.

While it is extremely unlikely to occur play it safe and cast right hand expression to wider type to mitigate the issue.

Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE.

Reference

https://git.kernel.org/stable/c/250423300b4b0335918be187ef3cade248c06e6a https://git.kernel.org/stable/c/6438ef381c183444f7f9d1de18f22661cba1e946 https://git.kernel.org/stable/c/b9495a9109abc31d3170f7aad7d48aa64610a1a2 https://git.kernel.org/stable/c/f2bd0f1ab47822fe5bd699c8458b896c4b2edea1 https://git.kernel.org/stable/c/f3d80f34f58445355fa27b9579a449fb186aa64e