[PATCH] remove redundant defines for dumpable states

From: Kees Cook
Date: Wed Feb 06 2013 - 14:44:32 EST


The existing SUID_DUMP_* defines duplicate the newer SUID_DUMPABLE_*
defines introduced in 54b501992dd2a839e94e76aa392c392b55080ce8. Remove
the new ones, and use the prior values instead.

Reported-by: Chen Gang <gang.chen@xxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Doug Ledford <dledford@xxxxxxxxxx>
Cc: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx>
Cc: James Morris <james.l.morris@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
fs/coredump.c | 2 +-
fs/exec.c | 10 +++++-----
fs/proc/internal.h | 3 ++-
include/linux/sched.h | 5 -----
kernel/sysctl.c | 2 +-
5 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/fs/coredump.c b/fs/coredump.c
index 1774932..57b9bd6 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -501,7 +501,7 @@ void do_coredump(siginfo_t *siginfo)
* so we dump it as root in mode 2, and only into a controlled
* environment (pipe handler or fully qualified path).
*/
- if (__get_dumpable(cprm.mm_flags) == SUID_DUMPABLE_SAFE) {
+ if (__get_dumpable(cprm.mm_flags) == SUID_DUMP_ROOT) {
/* Setuid core dump mode */
flag = O_EXCL; /* Stop rewrite attacks */
cred->fsuid = GLOBAL_ROOT_UID; /* Dump root private */
diff --git a/fs/exec.c b/fs/exec.c
index 20df02c..58841fe 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1111,7 +1111,7 @@ void setup_new_exec(struct linux_binprm * bprm)
current->sas_ss_sp = current->sas_ss_size = 0;

if (uid_eq(current_euid(), current_uid()) && gid_eq(current_egid(), current_gid()))
- set_dumpable(current->mm, SUID_DUMPABLE_ENABLED);
+ set_dumpable(current->mm, SUID_DUMP_USER);
else
set_dumpable(current->mm, suid_dumpable);

@@ -1639,17 +1639,17 @@ EXPORT_SYMBOL(set_binfmt);
void set_dumpable(struct mm_struct *mm, int value)
{
switch (value) {
- case SUID_DUMPABLE_DISABLED:
+ case SUID_DUMP_DISABLE:
clear_bit(MMF_DUMPABLE, &mm->flags);
smp_wmb();
clear_bit(MMF_DUMP_SECURELY, &mm->flags);
break;
- case SUID_DUMPABLE_ENABLED:
+ case SUID_DUMP_USER:
set_bit(MMF_DUMPABLE, &mm->flags);
smp_wmb();
clear_bit(MMF_DUMP_SECURELY, &mm->flags);
break;
- case SUID_DUMPABLE_SAFE:
+ case SUID_DUMP_ROOT:
set_bit(MMF_DUMP_SECURELY, &mm->flags);
smp_wmb();
set_bit(MMF_DUMPABLE, &mm->flags);
@@ -1662,7 +1662,7 @@ int __get_dumpable(unsigned long mm_flags)
int ret;

ret = mm_flags & MMF_DUMPABLE_MASK;
- return (ret > SUID_DUMPABLE_ENABLED) ? SUID_DUMPABLE_SAFE : ret;
+ return (ret > SUID_DUMP_USER) ? SUID_DUMP_ROOT : ret;
}

int get_dumpable(struct mm_struct *mm)
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 252544c..85ff3a4 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -11,6 +11,7 @@

#include <linux/sched.h>
#include <linux/proc_fs.h>
+#include <linux/binfmts.h>
struct ctl_table_header;
struct mempolicy;

@@ -108,7 +109,7 @@ static inline int task_dumpable(struct task_struct *task)
if (mm)
dumpable = get_dumpable(mm);
task_unlock(task);
- if (dumpable == SUID_DUMPABLE_ENABLED)
+ if (dumpable == SUID_DUMP_USER)
return 1;
return 0;
}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index d211247..03ffbdb 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -376,11 +376,6 @@ static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
extern void set_dumpable(struct mm_struct *mm, int value);
extern int get_dumpable(struct mm_struct *mm);

-/* get/set_dumpable() values */
-#define SUID_DUMPABLE_DISABLED 0
-#define SUID_DUMPABLE_ENABLED 1
-#define SUID_DUMPABLE_SAFE 2
-
/* mm flags */
/* dumpable bits */
#define MMF_DUMPABLE 0 /* core dump is permitted */
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c88878d..585015f 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2083,7 +2083,7 @@ int proc_dointvec_minmax(struct ctl_table *table, int write,
static void validate_coredump_safety(void)
{
#ifdef CONFIG_COREDUMP
- if (suid_dumpable == SUID_DUMPABLE_SAFE &&
+ if (suid_dumpable == SUID_DUMP_ROOT &&
core_pattern[0] != '/' && core_pattern[0] != '|') {
printk(KERN_WARNING "Unsafe core_pattern used with "\
"suid_dumpable=2. Pipe handler or fully qualified "\
--
1.7.9.5


--
Kees Cook
Chrome OS Security
--
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