Eric Lee / smarc-ti-linux-kernel

Download as
Browse Code ยป

Commit 28d7a6ae92c099d81cbea08c20be0d2cf7ccd7ca

Authored by Graff Yang
Committed by Linus Torvalds
1 parent 1915297566

nommu: check fd read permission in validate_mmap_request() 

According to the POSIX (1003.1-2008), the file descriptor shall have been
opened with read permission, regardless of the protection options specified to
mmap().  The ltp test cases mmap06/07 need this.

Signed-off-by: Graff Yang <graff.yang@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

... ... @@ -919,6 +919,10 @@
919 919 if (!file->f_op->read)
920 920 capabilities &= ~BDI_CAP_MAP_COPY;
921 921  
  922 + /* The file shall have been opened with read permission. */
  923 + if (!(file->f_mode & FMODE_READ))
  924 + return -EACCES;
  925 +
922 926 if (flags & MAP_SHARED) {
923 927 /* do checks for writing, appending and locking */
924 928 if ((prot & PROT_WRITE) &&