| Message ID | 20220924035226.3359297-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dlm: Split memcpy() of struct dlm_message flexible array | expand |
On Fri, Sep 23, 2022 at 08:52:26PM -0700, Kees Cook wrote: > To work around a misbehavior of the compiler's ability to see into > composite flexible array structs (as detailed in the coming memcpy() > hardening series[1]), split the memcpy() of the header and the payload > so no false positive run-time overflow warning will be generated. > > [1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@chromium.org/ > > Cc: Christine Caulfield <ccaulfie@redhat.com> > Cc: David Teigland <teigland@redhat.com> > Cc: cluster-devel@redhat.com > Reported-by: "Gustavo A. R. Silva" <gustavoars@kernel.org> > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks! -- Gustavo > --- > fs/dlm/requestqueue.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/dlm/requestqueue.c b/fs/dlm/requestqueue.c > index 036a9a0078f6..63f45c3c53a2 100644 > --- a/fs/dlm/requestqueue.c > +++ b/fs/dlm/requestqueue.c > @@ -44,7 +44,8 @@ void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, struct dlm_message *ms) > > e->recover_seq = ls->ls_recover_seq & 0xFFFFFFFF; > e->nodeid = nodeid; > - memcpy(&e->request, ms, le16_to_cpu(ms->m_header.h_length)); > + e->request = *ms; > + memcpy(&e->request.m_extra, ms->m_extra, length); > > atomic_inc(&ls->ls_requestqueue_cnt); > mutex_lock(&ls->ls_requestqueue_mutex); > -- > 2.34.1 >
diff --git a/fs/dlm/requestqueue.c b/fs/dlm/requestqueue.c index 036a9a0078f6..63f45c3c53a2 100644 --- a/fs/dlm/requestqueue.c +++ b/fs/dlm/requestqueue.c @@ -44,7 +44,8 @@ void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, struct dlm_message *ms) e->recover_seq = ls->ls_recover_seq & 0xFFFFFFFF; e->nodeid = nodeid; - memcpy(&e->request, ms, le16_to_cpu(ms->m_header.h_length)); + e->request = *ms; + memcpy(&e->request.m_extra, ms->m_extra, length); atomic_inc(&ls->ls_requestqueue_cnt); mutex_lock(&ls->ls_requestqueue_mutex);
To work around a misbehavior of the compiler's ability to see into composite flexible array structs (as detailed in the coming memcpy() hardening series[1]), split the memcpy() of the header and the payload so no false positive run-time overflow warning will be generated. [1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@chromium.org/ Cc: Christine Caulfield <ccaulfie@redhat.com> Cc: David Teigland <teigland@redhat.com> Cc: cluster-devel@redhat.com Reported-by: "Gustavo A. R. Silva" <gustavoars@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> --- fs/dlm/requestqueue.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)