diff options
Diffstat (limited to 'fs/open.c')
| -rw-r--r-- | fs/open.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/fs/open.c b/fs/open.c index 4401a73d4032..4478adcc4f3a 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1196,13 +1196,21 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op) } /* - * In order to ensure programs get explicit errors when trying to use - * O_TMPFILE on old kernels, O_TMPFILE is implemented such that it - * looks like (O_DIRECTORY|O_RDWR & ~O_CREAT) to old kernels. But we - * have to require userspace to explicitly set it. + * Block bugs where O_DIRECTORY | O_CREAT created regular files. + * Note, that blocking O_DIRECTORY | O_CREAT here also protects + * O_TMPFILE below which requires O_DIRECTORY being raised. */ + if ((flags & (O_DIRECTORY | O_CREAT)) == (O_DIRECTORY | O_CREAT)) + return -EINVAL; + + /* Now handle the creative implementation of O_TMPFILE. */ if (flags & __O_TMPFILE) { - if ((flags & O_TMPFILE_MASK) != O_TMPFILE) + /* + * In order to ensure programs get explicit errors when trying + * to use O_TMPFILE on old kernels we enforce that O_DIRECTORY + * is raised alongside __O_TMPFILE. + */ + if (!(flags & O_DIRECTORY)) return -EINVAL; if (!(acc_mode & MAY_WRITE)) return -EINVAL; |