Mercurial > vim
diff src/fileio.c @ 12771:8984342ab09e v8.0.1263
patch 8.0.1263: others can read the swap file if a user is careless
commit https://github.com/vim/vim/commit/5a73e0ca54c77e067c3b12ea6f35e3e8681e8cf8
Author: Bram Moolenaar <Bram@vim.org>
Date: Sat Nov 4 21:35:01 2017 +0100
patch 8.0.1263: others can read the swap file if a user is careless
Problem: Others can read the swap file if a user is careless with his
primary group.
Solution: If the group permission allows for reading but the world
permissions doesn't, make sure the group is right.
| author | Christian Brabandt <cb@256bit.org> |
|---|---|
| date | Sat, 04 Nov 2017 21:45:04 +0100 |
| parents | 351cf7c67bbe |
| children | 9d51b8c6b84e |
line wrap: on
line diff
--- a/src/fileio.c +++ b/src/fileio.c @@ -716,7 +716,29 @@ readfile( /* Set swap file protection bits after creating it. */ if (swap_mode > 0 && curbuf->b_ml.ml_mfp != NULL && curbuf->b_ml.ml_mfp->mf_fname != NULL) - (void)mch_setperm(curbuf->b_ml.ml_mfp->mf_fname, (long)swap_mode); + { + char_u *swap_fname = curbuf->b_ml.ml_mfp->mf_fname; + + /* + * If the group-read bit is set but not the world-read bit, then + * the group must be equal to the group of the original file. If + * we can't make that happen then reset the group-read bit. This + * avoids making the swap file readable to more users when the + * primary group of the user is too permissive. + */ + if ((swap_mode & 044) == 040) + { + stat_T swap_st; + + if (mch_stat((char *)swap_fname, &swap_st) >= 0 + && st.st_gid != swap_st.st_gid + && fchown(curbuf->b_ml.ml_mfp->mf_fd, -1, st.st_gid) + == -1) + swap_mode &= 0600; + } + + (void)mch_setperm(swap_fname, (long)swap_mode); + } #endif }