On 7/1/26 4:49 PM, Zhuoying Cai wrote:
Add address range tracking and overlap checks to ensure that no
component overlaps with a signed component during secure IPL.
Signed-off-by: Zhuoying Cai <[email protected]>
---
pc-bios/s390-ccw/secure-ipl.c | 19 +++++++++++++++++++
pc-bios/s390-ccw/secure-ipl.h | 6 ++++++
2 files changed, 25 insertions(+)
diff --git a/pc-bios/s390-ccw/secure-ipl.c b/pc-bios/s390-ccw/secure-ipl.c
index 2d9a4cbc02..af98881aa5 100644
--- a/pc-bios/s390-ccw/secure-ipl.c
+++ b/pc-bios/s390-ccw/secure-ipl.c
@@ -193,6 +193,23 @@ static void init_lists(IplDeviceComponentList *comp_list,
cert_list->ipl_info_header.len = sizeof(IplInfoBlockHeader);
}
+static void check_comp_overlap(IplDeviceComponentList *comp_list,
+ IplDeviceComponentEntry comp_entry)
+{
+ IplDeviceComponentEntry *comp;
+
+ /*
+ * Check component's address range does not overlap with any
+ * signed component's address range.
+ */
+ for_each_rb_entry(comp, comp_list) {
+ if (comp->flags & S390_IPL_DEV_COMP_FLAG_SC &&
+ intersects(comp->addr, comp->len, comp_entry.addr,
comp_entry.len)) {
+ zipl_secure_error("Component addresses overlap");
+ }
+ }
+}
+
static int zipl_load_signature(ComponentEntry *entry, uint64_t sig)
{
if (entry->compdat.sig_info.format != DER_SIGNATURE_FORMAT) {
@@ -287,6 +304,8 @@ int zipl_run_secure(ComponentEntry **entry_ptr, uint8_t
*tmp_sec,
comp_entry.addr = comp_addr;
comp_entry.len = (uint64_t)comp_len;
+ check_comp_overlap(comp_list, comp_entry);
+
/* no signature present (unsigned component) */
if (!sig_entry.len) {
comp_list_add(comp_list, comp_entry);
diff --git a/pc-bios/s390-ccw/secure-ipl.h b/pc-bios/s390-ccw/secure-ipl.h
index d5d6d6f7ac..1b1287858b 100644
--- a/pc-bios/s390-ccw/secure-ipl.h
+++ b/pc-bios/s390-ccw/secure-ipl.h
@@ -113,4 +113,10 @@ static inline bool
verify_signature(IplDeviceComponentEntry comp_entry,
return false;
}
+static inline bool intersects(uint64_t addr0, uint64_t size0,
+ uint64_t addr1, uint64_t size1)
+{
+ return addr0 + size0 > addr1 && addr1 + size1 > addr0;
+}
+
#endif /* _PC_BIOS_S390_CCW_SECURE_IPL_H */
Reviewed-by: Jared Rossi <[email protected]>
