git: 3866502e1817 - stable/13 - Revert "vfs_mount.c: Allow mountd(8) to do exports in a vnet prison"
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Date: Fri, 19 May 2023 21:37:42 UTC
The branch stable/13 has been updated by rmacklem:
URL: https://cgit.FreeBSD.org/src/commit/?id=3866502e1817aa28446d5e103277583bde65670d
commit 3866502e1817aa28446d5e103277583bde65670d
Author: Rick Macklem <rmacklem@FreeBSD.org>
AuthorDate: 2023-05-19 21:36:52 +0000
Commit: Rick Macklem <rmacklem@FreeBSD.org>
CommitDate: 2023-05-19 21:36:52 +0000
Revert "vfs_mount.c: Allow mountd(8) to do exports in a vnet prison"
Revert this commit until I can figure out build issue.
This reverts commit 527e6b02d65db8d6294b1e66f7bd063899a4de02.
---
sys/kern/vfs_mount.c | 107 +++++++--------------------------------------------
1 file changed, 14 insertions(+), 93 deletions(-)
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c
index e3a7ca50e792..4c941c2616ff 100644
--- a/sys/kern/vfs_mount.c
+++ b/sys/kern/vfs_mount.c
@@ -76,8 +76,7 @@ __FBSDID("$FreeBSD$");
#define VFS_MOUNTARG_SIZE_MAX (1024 * 64)
static int vfs_domount(struct thread *td, const char *fstype, char *fspath,
- uint64_t fsflags, bool jail_export,
- struct vfsoptlist **optlist);
+ uint64_t fsflags, struct vfsoptlist **optlist);
static void free_mntarg(struct mntarg *ma);
static int usermount = 0;
@@ -664,7 +663,7 @@ vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions)
struct vfsopt *opt, *tmp_opt;
char *fstype, *fspath, *errmsg;
int error, fstypelen, fspathlen, errmsg_len, errmsg_pos;
- bool autoro, has_nonexport, jail_export;
+ bool autoro;
errmsg = fspath = NULL;
errmsg_len = fspathlen = 0;
@@ -700,37 +699,15 @@ vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions)
goto bail;
}
- /*
- * Check to see that "export" is only used with the "update", "fstype",
- * "fspath", "from" and "errmsg" options when in a vnet jail.
- * These are the ones used to set/update exports by mountd(8).
- * If only the above options are set in a jail that can run mountd(8),
- * then the jail_export argument of vfs_domount() will be true.
- * When jail_export is true, the vfs_suser() check does not cause
- * failure, but limits the update to exports only.
- * This allows mountd(8) running within the vnet jail
- * to export file systems visible within the jail, but
- * mounted outside of the jail.
- */
/*
* We need to see if we have the "update" option
* before we call vfs_domount(), since vfs_domount() has special
* logic based on MNT_UPDATE. This is very important
* when we want to update the root filesystem.
*/
- has_nonexport = false;
- jail_export = false;
TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) {
int do_freeopt = 0;
- if (jailed(td->td_ucred) &&
- strcmp(opt->name, "export") != 0 &&
- strcmp(opt->name, "update") != 0 &&
- strcmp(opt->name, "fstype") != 0 &&
- strcmp(opt->name, "fspath") != 0 &&
- strcmp(opt->name, "from") != 0 &&
- strcmp(opt->name, "errmsg") != 0)
- has_nonexport = true;
if (strcmp(opt->name, "update") == 0) {
fsflags |= MNT_UPDATE;
do_freeopt = 1;
@@ -813,10 +790,9 @@ vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions)
fsflags |= MNT_SYNCHRONOUS;
else if (strcmp(opt->name, "union") == 0)
fsflags |= MNT_UNION;
- else if (strcmp(opt->name, "export") == 0) {
+ else if (strcmp(opt->name, "export") == 0)
fsflags |= MNT_EXPORTED;
- jail_export = true;
- } else if (strcmp(opt->name, "automounted") == 0) {
+ else if (strcmp(opt->name, "automounted") == 0) {
fsflags |= MNT_AUTOMOUNTED;
do_freeopt = 1;
} else if (strcmp(opt->name, "nocover") == 0) {
@@ -846,15 +822,7 @@ vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions)
goto bail;
}
- /*
- * If has_nonexport is true or the caller is not running within a
- * vnet prison that can run mountd(8), set jail_export false.
- */
- if (has_nonexport || !jailed(td->td_ucred) ||
- !prison_check_nfsd(td->td_ucred))
- jail_export = false;
-
- error = vfs_domount(td, fstype, fspath, fsflags, jail_export, &optlist);
+ error = vfs_domount(td, fstype, fspath, fsflags, &optlist);
if (error == ENOENT) {
error = EINVAL;
if (errmsg != NULL)
@@ -872,8 +840,7 @@ vfs_donmount(struct thread *td, uint64_t fsflags, struct uio *fsoptions)
printf("%s: R/W mount failed, possibly R/O media,"
" trying R/O mount\n", __func__);
fsflags |= MNT_RDONLY;
- error = vfs_domount(td, fstype, fspath, fsflags, jail_export,
- &optlist);
+ error = vfs_domount(td, fstype, fspath, fsflags, &optlist);
}
bail:
/* copyout the errmsg */
@@ -1147,7 +1114,6 @@ vfs_domount_update(
struct thread *td, /* Calling thread. */
struct vnode *vp, /* Mount point vnode. */
uint64_t fsflags, /* Flags common to all filesystems. */
- bool jail_export, /* Got export option in vnet prison. */
struct vfsoptlist **optlist /* Options local to the filesystem. */
)
{
@@ -1159,7 +1125,6 @@ vfs_domount_update(
int error, export_error, i, len;
uint64_t flag;
gid_t *grps;
- bool vfs_suser_failed;
ASSERT_VOP_ELOCKED(vp, __func__);
KASSERT((fsflags & MNT_UPDATE) != 0, ("MNT_UPDATE should be here"));
@@ -1188,20 +1153,7 @@ vfs_domount_update(
* Only privileged root, or (if MNT_USER is set) the user that
* did the original mount is permitted to update it.
*/
- /*
- * For the case of mountd(8) doing exports in a jail, the vfs_suser()
- * call does not cause failure. vfs_domount() has already checked
- * that "root" is doing this and vfs_suser() will fail when
- * the file system has been mounted outside the jail.
- * jail_export set true indicates that "export" is not mixed
- * with other options that change mount behaviour.
- */
- vfs_suser_failed = false;
error = vfs_suser(mp, td);
- if (jail_export && error != 0) {
- error = 0;
- vfs_suser_failed = true;
- }
if (error != 0) {
vput(vp);
return (error);
@@ -1231,26 +1183,11 @@ vfs_domount_update(
error = EBUSY;
goto end;
}
- if (vfs_suser_failed) {
- KASSERT((fsflags & (MNT_EXPORTED | MNT_UPDATE)) ==
- (MNT_EXPORTED | MNT_UPDATE),
- ("%s: jailed export did not set expected fsflags",
- __func__));
- /*
- * For this case, only MNT_UPDATE and
- * MNT_EXPORTED have been set in fsflags
- * by the options. Only set MNT_UPDATE,
- * since that is the one that would be set
- * when set in fsflags, below.
- */
- mp->mnt_flag |= MNT_UPDATE;
- } else {
- mp->mnt_flag &= ~MNT_UPDATEMASK;
- mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE |
- MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY);
- if ((mp->mnt_flag & MNT_ASYNC) == 0)
- mp->mnt_kern_flag &= ~MNTK_ASYNC;
- }
+ mp->mnt_flag &= ~MNT_UPDATEMASK;
+ mp->mnt_flag |= fsflags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE |
+ MNT_SNAPSHOT | MNT_ROOTFS | MNT_UPDATEMASK | MNT_RDONLY);
+ if ((mp->mnt_flag & MNT_ASYNC) == 0)
+ mp->mnt_kern_flag &= ~MNTK_ASYNC;
rootvp = vfs_cache_root_clear(mp);
MNT_IUNLOCK(mp);
mp->mnt_optnew = *optlist;
@@ -1261,17 +1198,7 @@ vfs_domount_update(
* XXX The final recipients of VFS_MOUNT just overwrite the ndp they
* get. No freeing of cn_pnbuf.
*/
- /*
- * For the case of mountd(8) doing exports from within a vnet jail,
- * "from" is typically not set correctly such that VFS_MOUNT() will
- * return ENOENT. It is not obvious that VFS_MOUNT() ever needs to be
- * called when mountd is doing exports, but this check only applies to
- * the specific case where it is running inside a vnet jail, to
- * avoid any POLA violation.
- */
- error = 0;
- if (!jail_export)
- error = VFS_MOUNT(mp);
+ error = VFS_MOUNT(mp);
export_error = 0;
/* Process the export option. */
@@ -1409,7 +1336,6 @@ vfs_domount(
const char *fstype, /* Filesystem type. */
char *fspath, /* Mount path. */
uint64_t fsflags, /* Flags common to all filesystems. */
- bool jail_export, /* Got export option in vnet prison. */
struct vfsoptlist **optlist /* Options local to the filesystem. */
)
{
@@ -1427,11 +1353,7 @@ vfs_domount(
if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN)
return (ENAMETOOLONG);
- if (jail_export) {
- error = priv_check(td, PRIV_NFS_DAEMON);
- if (error)
- return (error);
- } else if (jailed(td->td_ucred) || usermount == 0) {
+ if (jailed(td->td_ucred) || usermount == 0) {
if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0)
return (error);
}
@@ -1512,8 +1434,7 @@ vfs_domount(
}
free(pathbuf, M_TEMP);
} else
- error = vfs_domount_update(td, vp, fsflags, jail_export,
- optlist);
+ error = vfs_domount_update(td, vp, fsflags, optlist);
out:
NDFREE(&nd, NDF_ONLY_PNBUF);