[PATCH v1 4/4] powerpc/iommu: fix debugfs name buffer for 64-bit it_index
From: Xixin Liu <hidden>
Date: 2026-08-07 03:31:44
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
iommu debugfs names sprintf() "%08lx" into char name[10]. The "8" in %08lx is a minimum width, so a 64-bit it_index can need up to 16 hex digits plus NUL. Size the buffer for an unsigned long and use snprintf. Signed-off-by: Xixin Liu <redacted> --- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index ee1b5cb557c9..e8f48aef7832 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c@@ -53,10 +53,11 @@ static void iommu_debugfs_add(struct iommu_table *tbl) { - char name[10]; + /* unsigned long hex + NUL; %08lx is a minimum width only */ + char name[2 * sizeof(unsigned long) + 1]; struct dentry *liobn_entry; - sprintf(name, "%08lx", tbl->it_index); + snprintf(name, sizeof(name), "%08lx", tbl->it_index); liobn_entry = debugfs_create_dir(name, iommu_debugfs_dir); debugfs_create_file_unsafe("weight", 0400, liobn_entry, tbl, &iommu_debugfs_fops_weight);
@@ -70,9 +71,9 @@ static void iommu_debugfs_del(struct iommu_table *tbl) { - char name[10]; + char name[2 * sizeof(unsigned long) + 1]; - sprintf(name, "%08lx", tbl->it_index); + snprintf(name, sizeof(name), "%08lx", tbl->it_index); debugfs_lookup_and_remove(name, iommu_debugfs_dir); } #else
--
2.43.0