From: Jeff Xu <jeffxu@chromium.org>
Seal PROT and PKEY of the address range, in other words, mprotect()
and pkey_mprotect() will be denied if the memory is sealed with
MM_SEAL_PROT_PKEY.
Signed-off-by: Jeff Xu <jeffxu@chromium.org>
---
mm/mprotect.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/mm/mprotect.c b/mm/mprotect.c
index b94fbb45d5c7..1527188b1e92 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -32,6 +32,7 @@
#include <linux/sched/sysctl.h>
#include <linux/userfaultfd_k.h>
#include <linux/memory-tiers.h>
+#include <uapi/linux/mman.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>
@@ -753,6 +754,15 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
}
}
+ /*
+ * checking if PROT and PKEY is sealed.
+ * can_modify_mm assumes we have acquired the lock on MM.
+ */
+ if (!can_modify_mm(current->mm, start, end, MM_SEAL_PROT_PKEY)) {
+ error = -EACCES;
+ goto out;
+ }
+
prev = vma_prev(&vmi);
if (start > vma->vm_start)
prev = vma;
--
2.43.0.472.g3155946c3a-goog