Fix potential race condition in linux stat(2).

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D25618
This commit is contained in:
Edward Tomasz Napierala 2020-10-20 17:19:10 +00:00
parent bc3d569800
commit 1a34e9fad6
3 changed files with 22 additions and 7 deletions

View File

@ -80,11 +80,8 @@ translate_vnhook_major_minor(struct vnode *vp, struct stat *sb)
if (rootdevmp != NULL && vp->v_mount->mnt_vfc == rootdevmp->mnt_vfc)
sb->st_dev = rootdevmp->mnt_stat.f_fsid.val[0];
if (vp->v_type == VCHR && vp->v_rdev != NULL &&
linux_driver_get_major_minor(devtoname(vp->v_rdev),
&major, &minor) == 0) {
if (linux_vn_get_major_minor(vp, &major, &minor) == 0)
sb->st_rdev = (major << 8 | minor);
}
}
static int
@ -140,9 +137,7 @@ translate_fd_major_minor(struct thread *td, int fd, struct stat *buf)
if (mp != NULL && mp->mnt_vfc == rootdevmp->mnt_vfc)
buf->st_dev = rootdevmp->mnt_stat.f_fsid.val[0];
}
if (vp != NULL && vp->v_rdev != NULL &&
linux_driver_get_major_minor(devtoname(vp->v_rdev),
&major, &minor) == 0) {
if (linux_vn_get_major_minor(vp, &major, &minor) == 0) {
buf->st_rdev = (major << 8 | minor);
} else if (fp->f_type == DTYPE_PTS) {
struct tty *tp = fp->f_data;

View File

@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/lock.h>
#include <sys/malloc.h>
@ -195,6 +196,24 @@ linux_driver_get_major_minor(const char *node, int *major, int *minor)
return (1);
}
int
linux_vn_get_major_minor(const struct vnode *vp, int *major, int *minor)
{
int error;
if (vp->v_type != VCHR)
return (ENOTBLK);
dev_lock();
if (vp->v_rdev == NULL) {
dev_unlock();
return (ENXIO);
}
error = linux_driver_get_major_minor(devtoname(vp->v_rdev),
major, minor);
dev_unlock();
return (error);
}
char *
linux_get_char_devices()
{

View File

@ -123,6 +123,7 @@ int linux_device_register_handler(struct linux_device_handler *h);
int linux_device_unregister_handler(struct linux_device_handler *h);
char *linux_driver_get_name_dev(device_t dev);
int linux_driver_get_major_minor(const char *node, int *major, int *minor);
int linux_vn_get_major_minor(const struct vnode *vn, int *major, int *minor);
char *linux_get_char_devices(void);
void linux_free_get_char_devices(char *string);