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| author | Eugene Syromiatnikov <esyr@redhat.com> | 2020-04-12 22:26:58 +0200 |
|---|---|---|
| committer | Christian Brauner <christian.brauner@ubuntu.com> | 2020-04-15 09:56:32 +0200 |
| commit | a966dcfe153ab0a3d8d79cd971a079411a489be7 (patch) | |
| tree | 13ef1715ea1d89059e4e6738d7fd19dea930d5e2 /kernel | |
| parent | 62173872ca65767c586217dec0a32485da8a2f07 (diff) | |
| download | lwn-a966dcfe153ab0a3d8d79cd971a079411a489be7.tar.gz lwn-a966dcfe153ab0a3d8d79cd971a079411a489be7.zip | |
clone3: add build-time CLONE_ARGS_SIZE_VER* validity checks
CLONE_ARGS_SIZE_VER* macros are defined explicitly and not via
the offsets of the relevant struct clone_args fields, which makes
it rather error-prone, so it probably makes sense to add some
compile-time checks for them (including the one that breaks
on struct clone_args extension as a reminder to add a relevant
size macro and a similar check). Function copy_clone_args_from_user
seems to be a good place for such checks.
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20200412202658.GA31499@asgard.redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/fork.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 3ab7cf88e455..8c700f881d92 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2605,6 +2605,14 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs, struct clone_args args; pid_t *kset_tid = kargs->set_tid; + BUILD_BUG_ON(offsetofend(struct clone_args, tls) != + CLONE_ARGS_SIZE_VER0); + BUILD_BUG_ON(offsetofend(struct clone_args, set_tid_size) != + CLONE_ARGS_SIZE_VER1); + BUILD_BUG_ON(offsetofend(struct clone_args, cgroup) != + CLONE_ARGS_SIZE_VER2); + BUILD_BUG_ON(sizeof(struct clone_args) != CLONE_ARGS_SIZE_VER2); + if (unlikely(usize > PAGE_SIZE)) return -E2BIG; if (unlikely(usize < CLONE_ARGS_SIZE_VER0)) |