Messages in this thread Patch in this message | | | Date | Wed, 25 Nov 2009 10:59:03 -0800 | From | Sukadev Bhattiprolu <> | Subject | [v13][PATCH 06/12] Check invalid clone flags |
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From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Subject: [v13][PATCH 06/12] Check invalid clone flags
As pointed out by Oren Laadan, we want to ensure that unused bits in the clone-flags remain unused and available for future. To ensure this, define a mask of clone-flags and check the flags in the clone() system calls.
Changelog[v9]: - Include the unused clone-flag (CLONE_UNUSED) to VALID_CLONE_FLAGS to avoid breaking any applications that may have set it. IOW, this patch/check only applies to clone-flags bits 33 and higher.
Changelog[v8]: - New patch in set
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> --- include/linux/sched.h | 12 ++++++++++++ kernel/fork.c | 3 +++ 2 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h index 75e6e60..a4d2c23 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -29,6 +29,18 @@ #define CLONE_NEWNET 0x40000000 /* New network namespace */ #define CLONE_IO 0x80000000 /* Clone io context */ +#define CLONE_UNUSED 0x00001000 /* Can be reused ? */ + +#define VALID_CLONE_FLAGS (CSIGNAL | CLONE_VM | CLONE_FS | CLONE_FILES |\ + CLONE_SIGHAND | CLONE_UNUSED | CLONE_PTRACE |\ + CLONE_VFORK | CLONE_PARENT | CLONE_THREAD |\ + CLONE_NEWNS | CLONE_SYSVSEM | CLONE_SETTLS |\ + CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID |\ + CLONE_DETACHED | CLONE_UNTRACED |\ + CLONE_CHILD_SETTID | CLONE_STOPPED |\ + CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWUSER |\ + CLONE_NEWPID | CLONE_NEWNET | CLONE_IO) + /* * Scheduling policies */ diff --git a/kernel/fork.c b/kernel/fork.c index 72c76a1..317adcf 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -982,6 +982,9 @@ static struct task_struct *copy_process(unsigned long clone_flags, struct task_struct *p; int cgroup_callbacks_done = 0; + if (clone_flags & ~VALID_CLONE_FLAGS) + return ERR_PTR(-EINVAL); + if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS)) return ERR_PTR(-EINVAL); -- 1.6.0.4
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