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filedesc: cleanup setugidsafety a little

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Rename it to fdsetugidsafety for consistency with other functions.

There is no need to take filedesc lock if not closing any files.

The loop has to verify each file and we are guaranteed fdtable has space
for at least 20 fds. As such there is no need to check fd_lastfile.

While here tidy up is_unsafe.
This commit is contained in:
Mateusz Guzik 2014-10-22 00:23:43 +00:00
parent 07b384cbe2
commit 11888da8d9
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=273441
3 changed files with 12 additions and 16 deletions
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24
sys/kern/kern_descrip.c
View File

@ -2078,23 +2078,23 @@ fdescfree(struct thread *td)
* Since setugidsafety calls this only for fd 0, 1 and 2, this check is
* sufficient. We also don't check for setugidness since we know we are.
*/
static int
static bool
is_unsafe(struct file *fp)
{
if (fp->f_type == DTYPE_VNODE) {
struct vnode *vp = fp->f_vnode;
struct vnode *vp;
if ((vp->v_vflag & VV_PROCDEP) != 0)
return (1);
}
return (0);
if (fp->f_type != DTYPE_VNODE)
return (false);
vp = fp->f_vnode;
return ((vp->v_vflag & VV_PROCDEP) != 0);
}
/*
* Make this setguid thing safe, if at all possible.
*/
void
setugidsafety(struct thread *td)
fdsetugidsafety(struct thread *td)
{
struct filedesc *fdp;
struct file *fp;
@ -2102,12 +2102,10 @@ setugidsafety(struct thread *td)
fdp = td->td_proc->p_fd;
KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared"));
FILEDESC_XLOCK(fdp);
for (i = 0; i <= fdp->fd_lastfile; i++) {
if (i > 2)
break;
for (i = 0; i <= 2; i++) {
fp = fdp->fd_ofiles[i].fde_file;
if (fp != NULL && is_unsafe(fp)) {
FILEDESC_XLOCK(fdp);
knote_fdclose(td, i);
/*
* NULL-out descriptor prior to close to avoid
@ -2116,10 +2114,8 @@ setugidsafety(struct thread *td)
fdfree(fdp, i);
FILEDESC_XUNLOCK(fdp);
(void) closef(fp, td);
FILEDESC_XLOCK(fdp);
}
}
FILEDESC_XUNLOCK(fdp);
}
/*

2
sys/kern/kern_exec.c
View File

@ -695,7 +695,7 @@ do_execve(td, args, mac_p)
*/
PROC_UNLOCK(p);
VOP_UNLOCK(imgp->vp, 0);
setugidsafety(td);
fdsetugidsafety(td);
error = fdcheckstd(td);
if (error != 0)
goto done1;

2
sys/sys/filedesc.h
View File

@ -148,6 +148,7 @@ int fdallocn(struct thread *td, int minfd, int *fds, int n);
int fdcheckstd(struct thread *td);
void fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td);
void fdcloseexec(struct thread *td);
void fdsetugidsafety(struct thread *td);
struct filedesc *fdcopy(struct filedesc *fdp);
void fdunshare(struct thread *td);
void fdescfree(struct thread *td);
@ -159,7 +160,6 @@ struct filedesc_to_leader *
int getvnode(struct filedesc *fdp, int fd, cap_rights_t *rightsp,
struct file **fpp);
void mountcheckdirs(struct vnode *olddp, struct vnode *newdp);
void setugidsafety(struct thread *td);
/* Return a referenced file from an unlocked descriptor. */
int fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,