pagemap: do not leak physical addresses to non-privileged userspace

[pandora-kernel.git] / fs / proc / task_mmu.c

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ef1740d..d1bd6a9 100644 (file)
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -864,9 +864,19 @@ out:
        return ret;
 }
 
+static int pagemap_open(struct inode *inode, struct file *file)
+{
+       /* do not disclose physical addresses to unprivileged
+          userspace (closes a rowhammer attack vector) */
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+       return 0;
+}
+
 const struct file_operations proc_pagemap_operations = {
        .llseek         = mem_lseek, /* borrow this */
        .read           = pagemap_read,
+       .open           = pagemap_open,
 };
 #endif /* CONFIG_PROC_PAGE_MONITOR */