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Correct handling of locking for chroot() and chdir() cases: rather

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than having change_dir() release the vnode lock on success, hold the
lock so that we can use it later when invoking MAC checks and
VOP_ACCESS() in the chroot() code.  Update the comment to reflect
this calling convention.  Update callers to unlock the vnode
lock.  Correct a typo regarding vnode naming in the MAC case that
crept in via the previous patch applied.
This commit is contained in:
Robert Watson 2003-01-31 21:13:25 +00:00
parent 1b1cf40164
commit 565211b27f
2 changed files with 16 additions and 14 deletions
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15
sys/kern/vfs_extattr.c
View File

@ -465,6 +465,7 @@ kern_chdir(struct thread *td, char *path, enum uio_seg pathseg)
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, pathseg, path, td);
if ((error = change_dir(&nd, td)) != 0)
return (error);
VOP_UNLOCK(nd.ni_vp, 0, td);
NDFREE(&nd, NDF_ONLY_PNBUF);
FILEDESC_LOCK(fdp);
vp = fdp->fd_cdir;
@ -543,10 +544,11 @@ chroot(td, uap)
goto error;
#ifdef MAC
if ((error = mac_check_vnode_chroot(td->td_ucred, nd.ni_vp))) {
vput(vp);
vput(nd.ni_vp);
goto error;
}
#endif
VOP_UNLOCK(nd.ni_vp, 0, td);
FILEDESC_LOCK(fdp);
if (chroot_allow_open_directories == 0 ||
(chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) {
@ -574,7 +576,8 @@ chroot(td, uap)
}
/*
* Common routine for chroot and chdir.
* Common routine for chroot and chdir. On success, the directory vnode
* is returned locked, and must be unlocked by the caller.
*/
static int
change_dir(ndp, td)
@ -591,15 +594,13 @@ change_dir(ndp, td)
if (vp->v_type != VDIR)
error = ENOTDIR;
#ifdef MAC
else if ((error = mac_check_vnode_chdir(td->td_ucred, vp)) != 0) {
}
if (error == 0)
error = mac_check_vnode_chdir(td->td_ucred, vp);
#endif
else
if (error == 0)
error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
if (error)
vput(vp);
else
VOP_UNLOCK(vp, 0, td);
return (error);
}

15
sys/kern/vfs_syscalls.c
View File

@ -465,6 +465,7 @@ kern_chdir(struct thread *td, char *path, enum uio_seg pathseg)
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, pathseg, path, td);
if ((error = change_dir(&nd, td)) != 0)
return (error);
VOP_UNLOCK(nd.ni_vp, 0, td);
NDFREE(&nd, NDF_ONLY_PNBUF);
FILEDESC_LOCK(fdp);
vp = fdp->fd_cdir;
@ -543,10 +544,11 @@ chroot(td, uap)
goto error;
#ifdef MAC
if ((error = mac_check_vnode_chroot(td->td_ucred, nd.ni_vp))) {
vput(vp);
vput(nd.ni_vp);
goto error;
}
#endif
VOP_UNLOCK(nd.ni_vp, 0, td);
FILEDESC_LOCK(fdp);
if (chroot_allow_open_directories == 0 ||
(chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) {
@ -574,7 +576,8 @@ chroot(td, uap)
}
/*
* Common routine for chroot and chdir.
* Common routine for chroot and chdir. On success, the directory vnode
* is returned locked, and must be unlocked by the caller.
*/
static int
change_dir(ndp, td)
@ -591,15 +594,13 @@ change_dir(ndp, td)
if (vp->v_type != VDIR)
error = ENOTDIR;
#ifdef MAC
else if ((error = mac_check_vnode_chdir(td->td_ucred, vp)) != 0) {
}
if (error == 0)
error = mac_check_vnode_chdir(td->td_ucred, vp);
#endif
else
if (error == 0)
error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
if (error)
vput(vp);
else
VOP_UNLOCK(vp, 0, td);
return (error);
}