Change the argument to set_dumpable from task->mm to task. This allows us
to later add hooks to modify a task's property according to whether it is
a non-dumpable task. Non dumpable tasks demand a higher level of security.
Changes the dumpable value from in to unsigned int as negative number is
not allowed.
Signed-off-by: Tim Chen <tim.c.c...@linux.intel.com>
---
fs/exec.c | 14 ++++++++------
include/linux/sched/coredump.h | 2 +-
kernel/cred.c | 2 +-
kernel/sys.c | 2 +-
4 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index 1ebf6e5..e204830 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1362,9 +1362,9 @@ void setup_new_exec(struct linux_binprm * bprm)
if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||
!(uid_eq(current_euid(), current_uid()) &&
gid_eq(current_egid(), current_gid())))
- set_dumpable(current->mm, suid_dumpable);
+ set_dumpable(current, (unsigned int) suid_dumpable);
else
- set_dumpable(current->mm, SUID_DUMP_USER);
+ set_dumpable(current, SUID_DUMP_USER);
arch_setup_new_exec();
perf_event_exec();
@@ -1943,17 +1943,19 @@ EXPORT_SYMBOL(set_binfmt);
/*
* set_dumpable stores three-value SUID_DUMP_* into mm->flags.
*/
-void set_dumpable(struct mm_struct *mm, int value)
+void set_dumpable(struct task_struct *tsk, unsigned int value)
{
unsigned long old, new;
- if (WARN_ON((unsigned)value > SUID_DUMP_ROOT))
+ if (WARN_ON(value > SUID_DUMP_ROOT))
+ return;
+ if (WARN_ON(!tsk->mm))
return;
do {
- old = READ_ONCE(mm->flags);
+ old = READ_ONCE(tsk->mm->flags);
new = (old & ~MMF_DUMPABLE_MASK) | value;
- } while (cmpxchg(&mm->flags, old, new) != old);
+ } while (cmpxchg(&tsk->mm->flags, old, new) != old);
}
SYSCALL_DEFINE3(execve,
diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredump.h
index ec912d0..c02b1ab 100644
--- a/include/linux/sched/coredump.h
+++ b/include/linux/sched/coredump.h
@@ -14,7 +14,7 @@
#define MMF_DUMPABLE_BITS 2
#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
-extern void set_dumpable(struct mm_struct *mm, int value);
+extern void set_dumpable(struct task_struct *tsk, unsigned int value);
/*
* This returns the actual value of the suid_dumpable flag. For things
* that are using this for checking for privilege transitions, it must
diff --git a/kernel/cred.c b/kernel/cred.c
index ecf0365..18ef774 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -446,7 +446,7 @@ int commit_creds(struct cred *new)
!gid_eq(old->fsgid, new->fsgid) ||
!cred_cap_issubset(old, new)) {
if (task->mm)
- set_dumpable(task->mm, suid_dumpable);
+ set_dumpable(task, (unsigned int) suid_dumpable);
task->pdeath_signal = 0;
smp_wmb();
}
diff --git a/kernel/sys.c b/kernel/sys.c
index cf5c675..d0892cd 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2292,7 +2292,7 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2,
unsigned long, arg3,
error = -EINVAL;
break;
}
- set_dumpable(me->mm, arg2);
+ set_dumpable(me, (unsigned int) arg2);
break;
case PR_SET_UNALIGN:
--
2.9.4
