CVE-2026-52992

Description

In the Linux kernel, the following vulnerability has been resolved: fs/adfs: validate nzones in adfs_validate_bblk() Reject ADFS disc records with a zero zone count during boot block validation, before the disc record is used. When nzones is 0, adfs_read_map() passes it to kmalloc_array(0, ...) which returns ZERO_SIZE_PTR, and adfs_map_layout() then writes to dm[-1], causing an out-of-bounds write before the allocated buffer. adfs_validate_dr0() already rejects nzones != 1 for old-format images. Add the equivalent check to adfs_validate_bblk() for new-format images so that a crafted image with nzones == 0 is rejected at probe time. Found by syzkaller.

References

• https://git.kernel.org/stable/c/1586bd2d2fb436a26df20a70e78b000d34a7d159
• https://git.kernel.org/stable/c/1f0ed0f57f0fc87e46fe19a05435c214dc464be2
• https://git.kernel.org/stable/c/33aafd2418a59c96c0389d47ea09026661fa9ec6
• https://git.kernel.org/stable/c/60d82592ac8b5637fbed871381eb0a16df0a492e
• https://git.kernel.org/stable/c/6ff8cca5cdb4f2e0ea6d28ecd78479dd3f221ebc