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# HG changeset patch
# User Timo Lindfors <timo.lindfors@iki.fi>
# Date 1647554321 -7200
# Thu Mar 17 23:58:41 2022 +0200
# Node ID 97aaba204e327e32dc064418e67bad7045aaaccf
# Parent 9c625ab2035bae1fc38787025f74d2937600223b
Ignore modules that overlap with internal data structures
Without this patch the system can go to an infinite reboot loop as
corrupted module causes the system to reset.
Signed-off-by: Timo Lindfors <timo.lindfors@iki.fi>
diff -r 9c625ab2035b -r 97aaba204e32 include/config.h
--- a/include/config.h Thu Mar 10 10:28:11 2022 +0200
+++ b/include/config.h Thu Mar 17 23:58:41 2022 +0200
@@ -52,9 +52,10 @@
/* these addrs must be in low memory so that they are mapped by the */
/* kernel at startup */
+#define TBOOT_LOWMEM_START 0x60000
/* address/size for memory-resident serial log (when enabled) */
-#define TBOOT_SERIAL_LOG_ADDR 0x60000
+#define TBOOT_SERIAL_LOG_ADDR TBOOT_LOWMEM_START
#define TBOOT_SERIAL_LOG_SIZE 0x08000
/* address/size for modified e820 table */
@@ -72,6 +73,8 @@
TBOOT_EFI_MEMMAP_COPY_SIZE)
#define TBOOT_KERNEL_CMDLINE_SIZE 0x0400
+#define TBOOT_LOWMEM_END (TBOOT_KERNEL_CMDLINE_ADDR + \
+ TBOOT_KERNEL_CMDLINE_SIZE)
#ifndef NR_CPUS
#define NR_CPUS 1024
diff -r 9c625ab2035b -r 97aaba204e32 tboot/common/loader.c
--- a/tboot/common/loader.c Thu Mar 10 10:28:11 2022 +0200
+++ b/tboot/common/loader.c Thu Mar 17 23:58:41 2022 +0200
@@ -1807,6 +1807,42 @@
}
/*
+ * Check if two memory regions overlap
+ */
+static bool
+regions_overlap(const void *base1, size_t size1, const void *base2, size_t size2) {
+ /*
+ 11111
+ 22222
+ */
+ if (base1 <= base2 && base2 < base1 + size1) {
+ return true;
+ }
+ /*
+ 11111
+ 22222
+ */
+ if (base2 <= base1 && base1 < base2 + size2) {
+ return true;
+ }
+ /*
+ 1
+ 22222
+ */
+ if (base2 <= base1 && base1 + size1 < base2 + size2) {
+ return true;
+ }
+ /*
+ 11111
+ 2
+ */
+ if (base1 <= base2 && base2 + size2 < base1 + size1) {
+ return true;
+ }
+ return false;
+}
+
+/*
* will go through all modules to find an SINIT that matches the platform
* (size can be NULL)
*/
@@ -1836,6 +1872,11 @@
void *base2 = (void *)m->mod_start;
uint32_t size2 = m->mod_end - (unsigned long)(base2);
+ if (regions_overlap(base2, size2,
+ (void*)TBOOT_LOWMEM_START, TBOOT_LOWMEM_END - TBOOT_LOWMEM_START)) {
+ printk(TBOOT_DETA "Ignoring module as it overlaps with tboot's internal data structures\n");
+ continue;
+ }
if ( is_sinit_acmod(base2, size2, false) &&
does_acmod_match_platform((acm_hdr_t *)base2, NULL) ) {
if ( base != NULL )
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