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-rw-r--r--fs/coredump.c66
1 files changed, 61 insertions, 5 deletions
diff --git a/fs/coredump.c b/fs/coredump.c
index 7dece20b162b..1c060c0a2d72 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -41,6 +41,7 @@
#include <linux/fs.h>
#include <linux/path.h>
#include <linux/timekeeping.h>
+#include <linux/sysctl.h>
#include <linux/uaccess.h>
#include <asm/mmu_context.h>
@@ -52,9 +53,9 @@
#include <trace/events/sched.h>
-int core_uses_pid;
-unsigned int core_pipe_limit;
-char core_pattern[CORENAME_MAX_SIZE] = "core";
+static int core_uses_pid;
+static unsigned int core_pipe_limit;
+static char core_pattern[CORENAME_MAX_SIZE] = "core";
static int core_name_size = CORENAME_MAX_SIZE;
struct core_name {
@@ -62,8 +63,6 @@ struct core_name {
int used, size;
};
-/* The maximal length of core_pattern is also specified in sysctl.c */
-
static int expand_corename(struct core_name *cn, int size)
{
char *corename = krealloc(cn->corename, size, GFP_KERNEL);
@@ -893,6 +892,63 @@ int dump_align(struct coredump_params *cprm, int align)
}
EXPORT_SYMBOL(dump_align);
+#ifdef CONFIG_SYSCTL
+
+void validate_coredump_safety(void)
+{
+ if (suid_dumpable == SUID_DUMP_ROOT &&
+ core_pattern[0] != '/' && core_pattern[0] != '|') {
+ pr_warn(
+"Unsafe core_pattern used with fs.suid_dumpable=2.\n"
+"Pipe handler or fully qualified core dump path required.\n"
+"Set kernel.core_pattern before fs.suid_dumpable.\n"
+ );
+ }
+}
+
+static int proc_dostring_coredump(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp, loff_t *ppos)
+{
+ int error = proc_dostring(table, write, buffer, lenp, ppos);
+
+ if (!error)
+ validate_coredump_safety();
+ return error;
+}
+
+static struct ctl_table coredump_sysctls[] = {
+ {
+ .procname = "core_uses_pid",
+ .data = &core_uses_pid,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "core_pattern",
+ .data = core_pattern,
+ .maxlen = CORENAME_MAX_SIZE,
+ .mode = 0644,
+ .proc_handler = proc_dostring_coredump,
+ },
+ {
+ .procname = "core_pipe_limit",
+ .data = &core_pipe_limit,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ { }
+};
+
+static int __init init_fs_coredump_sysctls(void)
+{
+ register_sysctl_init("kernel", coredump_sysctls);
+ return 0;
+}
+fs_initcall(init_fs_coredump_sysctls);
+#endif /* CONFIG_SYSCTL */
+
/*
* The purpose of always_dump_vma() is to make sure that special kernel mappings
* that are useful for post-mortem analysis are included in every core dump.