Re: [RFC PATCH v1 1/2] mm/memfd: Add support for F_SEAL_FUTURE_EXEC to memfd

On Fri, Dec 06, 2024 at 09:49:35AM -0800, Kalesh Singh wrote:

On Thu, Dec 5, 2024 at 5:09 PM Isaac J. Manjarres isaacmanjarres@google.com wrote:

...

--- a/mm/mmap.c +++ b/mm/mmap.c @@ -375,6 +375,17 @@ unsigned long do_mmap(struct file *file, unsigned long addr, if (!file_mmap_ok(file, inode, pgoff, len)) return -EOVERFLOW;

•           if (is_exec_sealed(seals)) {
  

•                   /* No new executable mappings if the file is exec sealed. */
  

•                   if (prot & PROT_EXEC)
  

•                           return -EACCES;
  

I think this should be -EPERM to be consistent with seal_check_write() and mmap(2) man page:

" EPERM The operation was prevented by a file seal; see fcntl(2)."

Thanks, Kalesh

Thanks for catching that Kalesh! I agree and will fix this in v2 of the series.

Thanks, Isaac