Merge tag 'seccomp-v5.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull seccomp fixes from Kees Cook:
 "Syzbot found a use-after-free bug in seccomp due to flags that should
  not be allowed to be used together.

  Tycho fixed this, I updated the self-tests, and the syzkaller PoC has
  been running for several days without triggering KASan (before this
  fix, it would reproduce). These patches have also been in -next for
  almost a week, just to be sure.

   - Add logic for making some seccomp flags exclusive (Tycho)

   - Update selftests for exclusivity testing (Kees)"

* tag 'seccomp-v5.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  seccomp: Make NEW_LISTENER and TSYNC flags exclusive
  selftests/seccomp: Prepare for exclusive seccomp flags
This commit is contained in:
Linus Torvalds
2019-04-29 13:24:34 -07:00
2 changed files with 40 additions and 11 deletions

View File

@@ -2166,11 +2166,14 @@ TEST(detect_seccomp_filter_flags)
SECCOMP_FILTER_FLAG_LOG,
SECCOMP_FILTER_FLAG_SPEC_ALLOW,
SECCOMP_FILTER_FLAG_NEW_LISTENER };
unsigned int flag, all_flags;
unsigned int exclusive[] = {
SECCOMP_FILTER_FLAG_TSYNC,
SECCOMP_FILTER_FLAG_NEW_LISTENER };
unsigned int flag, all_flags, exclusive_mask;
int i;
long ret;
/* Test detection of known-good filter flags */
/* Test detection of individual known-good filter flags */
for (i = 0, all_flags = 0; i < ARRAY_SIZE(flags); i++) {
int bits = 0;
@@ -2197,16 +2200,29 @@ TEST(detect_seccomp_filter_flags)
all_flags |= flag;
}
/* Test detection of all known-good filter flags */
ret = seccomp(SECCOMP_SET_MODE_FILTER, all_flags, NULL);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EFAULT, errno) {
TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
all_flags);
/*
* Test detection of all known-good filter flags combined. But
* for the exclusive flags we need to mask them out and try them
* individually for the "all flags" testing.
*/
exclusive_mask = 0;
for (i = 0; i < ARRAY_SIZE(exclusive); i++)
exclusive_mask |= exclusive[i];
for (i = 0; i < ARRAY_SIZE(exclusive); i++) {
flag = all_flags & ~exclusive_mask;
flag |= exclusive[i];
ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EFAULT, errno) {
TH_LOG("Failed to detect that all known-good filter flags (0x%X) are supported!",
flag);
}
}
/* Test detection of an unknown filter flag */
/* Test detection of an unknown filter flags, without exclusives. */
flag = -1;
flag &= ~exclusive_mask;
ret = seccomp(SECCOMP_SET_MODE_FILTER, flag, NULL);
EXPECT_EQ(-1, ret);
EXPECT_EQ(EINVAL, errno) {