Eric Lee / linux-smarc-t335x-v3.2

Download as
Browse Code ยป

Commit 5a211a5deabcafdc764817d5b4510c767d317ddc

Authored by Eric Paris
Committed by James Morris
1 parent 7cd94146cd
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

VM/Security: add security hook to do_brk 

Given a specifically crafted binary do_brk() can be used to get low
pages available in userspace virtually memory and can thus be used to
circumvent the mmap_min_addr low memory protection.  Add security checks
in do_brk().

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

Showing 1 changed file with 4 additions and 0 deletions Side-by-side Diff

... ... @@ -1941,6 +1941,10 @@
1941 1941 if (is_hugepage_only_range(mm, addr, len))
1942 1942 return -EINVAL;
1943 1943  
  1944 + error = security_file_mmap(0, 0, 0, 0, addr, 1);
  1945 + if (error)
  1946 + return error;
  1947 +
1944 1948 flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
1945 1949  
1946 1950 error = arch_mmap_check(addr, len, flags);