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authorJames Morris <jmorris@namei.org>2018-02-22 10:50:24 -0800
committerJames Morris <jmorris@namei.org>2018-02-22 10:50:24 -0800
commit645ae5c51e85d7dbb25177866d5016a89d5243ad (patch)
treea4d638616c5db0bde980c6bf5b494f70b6bbef0c
parentaf3e79d29555b97dd096e2f8e36a0f50213808a8 (diff)
parentd057dc4e35e16050befa3dda943876dab39cbf80 (diff)
Merge tag 'seccomp-v4.16-rc3' of https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into fixes-v4.16-rc3
- Fix seccomp GET_METADATA to deal with field sizes correctly (Tycho Andersen) - Add selftest to make sure GET_METADATA doesn't regress (Tycho Andersen)
-rw-r--r--include/uapi/linux/ptrace.h4
-rw-r--r--kernel/seccomp.c6
-rw-r--r--tools/testing/selftests/seccomp/seccomp_bpf.c61
3 files changed, 67 insertions, 4 deletions
diff --git a/include/uapi/linux/ptrace.h b/include/uapi/linux/ptrace.h
index e46d82b91166..d5a1b8a492b9 100644
--- a/include/uapi/linux/ptrace.h
+++ b/include/uapi/linux/ptrace.h
@@ -69,8 +69,8 @@ struct ptrace_peeksiginfo_args {
#define PTRACE_SECCOMP_GET_METADATA 0x420d
struct seccomp_metadata {
- unsigned long filter_off; /* Input: which filter */
- unsigned int flags; /* Output: filter's flags */
+ __u64 filter_off; /* Input: which filter */
+ __u64 flags; /* Output: filter's flags */
};
/* Read signals from a shared (process wide) queue */
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 940fa408a288..dc77548167ef 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1076,14 +1076,16 @@ long seccomp_get_metadata(struct task_struct *task,
size = min_t(unsigned long, size, sizeof(kmd));
- if (copy_from_user(&kmd, data, size))
+ if (size < sizeof(kmd.filter_off))
+ return -EINVAL;
+
+ if (copy_from_user(&kmd.filter_off, data, sizeof(kmd.filter_off)))
return -EFAULT;
filter = get_nth_filter(task, kmd.filter_off);
if (IS_ERR(filter))
return PTR_ERR(filter);
- memset(&kmd, 0, sizeof(kmd));
if (filter->log)
kmd.flags |= SECCOMP_FILTER_FLAG_LOG;
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 0b457e8e0f0c..5df609950a66 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -141,6 +141,15 @@ struct seccomp_data {
#define SECCOMP_FILTER_FLAG_LOG 2
#endif
+#ifndef PTRACE_SECCOMP_GET_METADATA
+#define PTRACE_SECCOMP_GET_METADATA 0x420d
+
+struct seccomp_metadata {
+ __u64 filter_off; /* Input: which filter */
+ __u64 flags; /* Output: filter's flags */
+};
+#endif
+
#ifndef seccomp
int seccomp(unsigned int op, unsigned int flags, void *args)
{
@@ -2845,6 +2854,58 @@ TEST(get_action_avail)
EXPECT_EQ(errno, EOPNOTSUPP);
}
+TEST(get_metadata)
+{
+ pid_t pid;
+ int pipefd[2];
+ char buf;
+ struct seccomp_metadata md;
+
+ ASSERT_EQ(0, pipe(pipefd));
+
+ pid = fork();
+ ASSERT_GE(pid, 0);
+ if (pid == 0) {
+ struct sock_filter filter[] = {
+ BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
+ };
+ struct sock_fprog prog = {
+ .len = (unsigned short)ARRAY_SIZE(filter),
+ .filter = filter,
+ };
+
+ /* one with log, one without */
+ ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER,
+ SECCOMP_FILTER_FLAG_LOG, &prog));
+ ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog));
+
+ ASSERT_EQ(0, close(pipefd[0]));
+ ASSERT_EQ(1, write(pipefd[1], "1", 1));
+ ASSERT_EQ(0, close(pipefd[1]));
+
+ while (1)
+ sleep(100);
+ }
+
+ ASSERT_EQ(0, close(pipefd[1]));
+ ASSERT_EQ(1, read(pipefd[0], &buf, 1));
+
+ ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid));
+ ASSERT_EQ(pid, waitpid(pid, NULL, 0));
+
+ md.filter_off = 0;
+ ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md));
+ EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG);
+ EXPECT_EQ(md.filter_off, 0);
+
+ md.filter_off = 1;
+ ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md));
+ EXPECT_EQ(md.flags, 0);
+ EXPECT_EQ(md.filter_off, 1);
+
+ ASSERT_EQ(0, kill(pid, SIGKILL));
+}
+
/*
* TODO:
* - add microbenchmarks