sysctl: fix write access to dmesg_restrict/kptr_restrict
Commit bfdc0b4 adds code to restrict access to dmesg_restrict,
however, it incorrectly alters kptr_restrict rather than
dmesg_restrict.
The original patch from Richard Weinberger
(https://lkml.org/lkml/2011/3/14/362) alters dmesg_restrict as
expected, and so the patch seems to have been misapplied.
This adds the CAP_SYS_ADMIN check to both dmesg_restrict and
kptr_restrict, since both are sensitive.
Reported-by: Phillip Lougher <plougher@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 52b3a06..4ab1187 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -170,7 +170,7 @@
#endif
#ifdef CONFIG_PRINTK
-static int proc_dmesg_restrict(struct ctl_table *table, int write,
+static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos);
#endif
@@ -703,7 +703,7 @@
.data = &dmesg_restrict,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = proc_dointvec_minmax,
+ .proc_handler = proc_dointvec_minmax_sysadmin,
.extra1 = &zero,
.extra2 = &one,
},
@@ -712,7 +712,7 @@
.data = &kptr_restrict,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = proc_dmesg_restrict,
+ .proc_handler = proc_dointvec_minmax_sysadmin,
.extra1 = &zero,
.extra2 = &two,
},
@@ -1943,7 +1943,7 @@
}
#ifdef CONFIG_PRINTK
-static int proc_dmesg_restrict(struct ctl_table *table, int write,
+static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
if (write && !capable(CAP_SYS_ADMIN))
