#include <linux/path.h>
#include <linux/timekeeping.h>
#include <linux/sysctl.h>
+#include <linux/elf.h>
#include <linux/uaccess.h>
#include <asm/mmu_context.h>
return false;
}
+#define DUMP_SIZE_MAYBE_ELFHDR_PLACEHOLDER 1
+
/*
* Decide how much of @vma's contents should be included in a core dump.
*/
* dump the first page to aid in determining what was mapped here.
*/
if (FILTER(ELF_HEADERS) &&
- vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ) &&
- (READ_ONCE(file_inode(vma->vm_file)->i_mode) & 0111) != 0)
- return PAGE_SIZE;
+ vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
+ if ((READ_ONCE(file_inode(vma->vm_file)->i_mode) & 0111) != 0)
+ return PAGE_SIZE;
+
+ /*
+ * ELF libraries aren't always executable.
+ * We'll want to check whether the mapping starts with the ELF
+ * magic, but not now - we're holding the mmap lock,
+ * so copy_from_user() doesn't work here.
+ * Use a placeholder instead, and fix it up later in
+ * dump_vma_snapshot().
+ */
+ return DUMP_SIZE_MAYBE_ELFHDR_PLACEHOLDER;
+ }
#undef FILTER
m->end = vma->vm_end;
m->flags = vma->vm_flags;
m->dump_size = vma_dump_size(vma, cprm->mm_flags);
-
- vma_data_size += m->dump_size;
}
mmap_write_unlock(mm);
return -EFAULT;
}
+ for (i = 0; i < *vma_count; i++) {
+ struct core_vma_metadata *m = (*vma_meta) + i;
+
+ if (m->dump_size == DUMP_SIZE_MAYBE_ELFHDR_PLACEHOLDER) {
+ char elfmag[SELFMAG];
+
+ if (copy_from_user(elfmag, (void __user *)m->start, SELFMAG) ||
+ memcmp(elfmag, ELFMAG, SELFMAG) != 0) {
+ m->dump_size = 0;
+ } else {
+ m->dump_size = PAGE_SIZE;
+ }
+ }
+
+ vma_data_size += m->dump_size;
+ }
+
*vma_data_size_ptr = vma_data_size;
return 0;
}