In the Linux kernel, the following vulnerability has been resolved: iommu/amd: Fix undefined behavior in devid_write debugfs function When for_each_pci_segment() loop completes without finding a matching segment, the pci_seg pointer is not NULL but points to an invalid memory location (the list head). Accessing pci_seg->id after the loop causes undefined behavior. Fix this by handling the successful case inside the loop and returning -EINVAL after the loop if no matching segment is found.
https://git.kernel.org/stable/c/99d42aef089a07cfb1d404a7227ac9dc7628b497
https://git.kernel.org/stable/c/8aabe0fba01486b5d893e708b05a8fa7f1b7efbb
https://git.kernel.org/stable/c/843e149989665f8309ad2efe6048dc76591e1f94