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.

Fixes: 2e98940f123d9 ("iommu/amd: Add support for device id user input")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Ankit Soni <Ankit.Soni@amd.com>
Signed-off-by: Will Deacon <will@kernel.org>

0 files changed, 0 insertions, 0 deletions