Restrict visibility of per-dataset kstats inside FreeBSD jails

When inside a jail, visibility on datasets not "jailed" to the
jail is restricted. However, it was possible to enumerate all
datasets in the pool by looking at the kstats sysctl MIB.

Only the kstats corresponding to datasets that the user has
visibility on are accessible now.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Closes #14254
This commit is contained in:
Allan Jude 2022-12-09 14:04:29 -05:00 committed by Tony Hutter
parent 24a6d8316a
commit 6219190d7f
1 changed files with 79 additions and 10 deletions

View File

@ -39,6 +39,7 @@ __FBSDID("$FreeBSD$");
#include <sys/sysctl.h> #include <sys/sysctl.h>
#include <sys/kstat.h> #include <sys/kstat.h>
#include <sys/sbuf.h> #include <sys/sbuf.h>
#include <sys/zone.h>
static MALLOC_DEFINE(M_KSTAT, "kstat_data", "Kernel statistics"); static MALLOC_DEFINE(M_KSTAT, "kstat_data", "Kernel statistics");
@ -134,6 +135,55 @@ kstat_sysctl_string(SYSCTL_HANDLER_ARGS)
return (sysctl_handle_string(oidp, val, len, req)); return (sysctl_handle_string(oidp, val, len, req));
} }
static int
kstat_sysctl_dataset(SYSCTL_HANDLER_ARGS)
{
kstat_t *ksp = arg1;
kstat_named_t *ksent;
kstat_named_t *ksent_ds;
uint64_t val;
char *ds_name;
uint32_t ds_len = 0;
ksent_ds = ksent = ksp->ks_data;
ds_name = KSTAT_NAMED_STR_PTR(ksent_ds);
ds_len = KSTAT_NAMED_STR_BUFLEN(ksent_ds);
ds_name[ds_len-1] = '\0';
if (!zone_dataset_visible(ds_name, NULL)) {
return (EPERM);
}
/* Select the correct element */
ksent += arg2;
/* Update the aggsums before reading */
(void) ksp->ks_update(ksp, KSTAT_READ);
val = ksent->value.ui64;
return (sysctl_handle_64(oidp, &val, 0, req));
}
static int
kstat_sysctl_dataset_string(SYSCTL_HANDLER_ARGS)
{
kstat_t *ksp = arg1;
kstat_named_t *ksent = ksp->ks_data;
char *val;
uint32_t len = 0;
/* Select the correct element */
ksent += arg2;
val = KSTAT_NAMED_STR_PTR(ksent);
len = KSTAT_NAMED_STR_BUFLEN(ksent);
val[len-1] = '\0';
if (!zone_dataset_visible(val, NULL)) {
return (EPERM);
}
return (sysctl_handle_string(oidp, val, len, req));
}
static int static int
kstat_sysctl_io(SYSCTL_HANDLER_ARGS) kstat_sysctl_io(SYSCTL_HANDLER_ARGS)
{ {
@ -422,11 +472,20 @@ kstat_install_named(kstat_t *ksp)
ksp, i, kstat_sysctl, "Q", namelast); ksp, i, kstat_sysctl, "Q", namelast);
break; break;
case KSTAT_DATA_UINT64: case KSTAT_DATA_UINT64:
SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx, if (strcmp(ksp->ks_class, "dataset") == 0) {
SYSCTL_CHILDREN(ksp->ks_sysctl_root), SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
OID_AUTO, namelast, SYSCTL_CHILDREN(ksp->ks_sysctl_root),
CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE, OID_AUTO, namelast,
ksp, i, kstat_sysctl, "QU", namelast); CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE,
ksp, i, kstat_sysctl_dataset, "QU",
namelast);
} else {
SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
SYSCTL_CHILDREN(ksp->ks_sysctl_root),
OID_AUTO, namelast,
CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE,
ksp, i, kstat_sysctl, "QU", namelast);
}
break; break;
case KSTAT_DATA_LONG: case KSTAT_DATA_LONG:
SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx, SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
@ -443,11 +502,21 @@ kstat_install_named(kstat_t *ksp)
ksp, i, kstat_sysctl, "LU", namelast); ksp, i, kstat_sysctl, "LU", namelast);
break; break;
case KSTAT_DATA_STRING: case KSTAT_DATA_STRING:
SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx, if (strcmp(ksp->ks_class, "dataset") == 0) {
SYSCTL_CHILDREN(ksp->ks_sysctl_root), SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
OID_AUTO, namelast, SYSCTL_CHILDREN(ksp->ks_sysctl_root),
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, OID_AUTO, namelast, CTLTYPE_STRING |
ksp, i, kstat_sysctl_string, "A", namelast); CTLFLAG_RD | CTLFLAG_MPSAFE,
ksp, i, kstat_sysctl_dataset_string, "A",
namelast);
} else {
SYSCTL_ADD_PROC(&ksp->ks_sysctl_ctx,
SYSCTL_CHILDREN(ksp->ks_sysctl_root),
OID_AUTO, namelast, CTLTYPE_STRING |
CTLFLAG_RD | CTLFLAG_MPSAFE,
ksp, i, kstat_sysctl_string, "A",
namelast);
}
break; break;
default: default:
panic("unsupported type: %d", typelast); panic("unsupported type: %d", typelast);