Include FMODE_EXEC when building the f_mode field, so that code can
actually test the correct field and values. Only three places actually
examine f_flags for FMODE_EXEC:
fs/open.c: if (unlikely((f->f_mode & FMODE_EXEC) && !S_ISREG(inode->i_mode))) {
include/linux/fsnotify.h: if (file->f_mode & FMODE_EXEC) {
include/linux/fsnotify.h: if (file->f_mode & FMODE_EXEC)
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
I assume there must be some reason for FMODE_EXEC not being pulled into
f_mode, but I couldn't find it. I guess this is my attempt to either fix
an oversight or to learn by flames. :)
---
fs/namei.c | 4 ++--
include/linux/fs.h | 3 ++-
include/linux/fsnotify.h | 4 ++--
3 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 6bb1b6624bad..362b1cc75f5c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3213,8 +3213,8 @@ static int do_open(struct nameidata *nd,
return -ENOTDIR;
/* Opening for execution requires a regular file on an exec mnt. */
- if ((file->f_flags & FMODE_EXEC) && (!d_is_reg(nd->path.dentry) ||
- path_noexec(&nd->path)))
+ if ((file->f_mode & FMODE_EXEC) && (!d_is_reg(nd->path.dentry) ||
+ path_noexec(&nd->path)))
return -EACCES;
do_truncate = false;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4f6f59b4f22a..8a2cabdcf531 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3545,10 +3545,11 @@ int __init get_filesystem_list(char *buf);
#define __FMODE_EXEC ((__force int) FMODE_EXEC)
#define __FMODE_NONOTIFY ((__force int) FMODE_NONOTIFY)
+#define __SMUGGLED_FMODE_FLAGS (__FMODE_EXEC | __FMODE_NONOTIFY)
#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
#define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
- (flag & __FMODE_NONOTIFY)))
+ (flag & __SMUGGLED_FMODE_FLAGS)))
static inline bool is_sxid(umode_t mode)
{
diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index 5ab28f6c7d26..86761ed4b434 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -90,7 +90,7 @@ static inline int fsnotify_perm(struct file *file, int mask)
if (mask & MAY_OPEN) {
fsnotify_mask = FS_OPEN_PERM;
- if (file->f_flags & __FMODE_EXEC) {
+ if (file->f_mode & FMODE_EXEC) {
ret = fsnotify_file(file, FS_OPEN_EXEC_PERM);
if (ret)
@@ -264,7 +264,7 @@ static inline void fsnotify_open(struct file *file)
{
__u32 mask = FS_OPEN;
- if (file->f_flags & __FMODE_EXEC)
+ if (file->f_mode & FMODE_EXEC)
mask |= FS_OPEN_EXEC;
fsnotify_file(file, mask);
--
2.20.1
