On Fri, 7 Jul 2023 at 05:11, Mahesh Salgaonkar <mah...@linux.ibm.com> wrote: > > opal_prd_msg_notifier extracts the opal prd message size from the message > header and uses it for allocating opal_prd_msg_queue_item that includes > the correct message size to be copied. However, while running under > CONFIG_FORTIFY_SOURCE=y, it triggers following run-time warning: > > [ 6458.234352] memcpy: detected field-spanning write (size 32) of single > field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355 (size 4) > [ 6458.234390] WARNING: CPU: 9 PID: 660 at > arch/powerpc/platforms/powernv/opal-prd.c:355 > opal_prd_msg_notifier+0x174/0x188 [opal_prd] > [...] > [ 6458.234709] NIP [c00800000e0c0e6c] opal_prd_msg_notifier+0x174/0x188 > [opal_prd] > [ 6458.234723] LR [c00800000e0c0e68] opal_prd_msg_notifier+0x170/0x188 > [opal_prd] > [ 6458.234736] Call Trace: > [ 6458.234742] [c0000002acb23c10] [c00800000e0c0e68] > opal_prd_msg_notifier+0x170/0x188 [opal_prd] (unreliable) > [ 6458.234759] [c0000002acb23ca0] [c00000000019ccc0] > notifier_call_chain+0xc0/0x1b0 > [ 6458.234774] [c0000002acb23d00] [c00000000019ceac] > atomic_notifier_call_chain+0x2c/0x40 > [ 6458.234788] [c0000002acb23d20] [c0000000000d69b4] > opal_message_notify+0xf4/0x2c0 > [...] > > Split the copy to avoid false positive run-time warning. > > Reported-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> > Signed-off-by: Mahesh Salgaonkar <mah...@linux.ibm.com>
I hit this on a box running the Ubuntu 6.2.0-27-generic kernel. Do we plan on merging this fix? > --- > Change from v1: > - Rework the memcpy to copy message header and rest of the message > separately without adding flex array. > --- > arch/powerpc/platforms/powernv/opal-prd.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/platforms/powernv/opal-prd.c > b/arch/powerpc/platforms/powernv/opal-prd.c > index 113bdb151f687..a068cbc4d43c0 100644 > --- a/arch/powerpc/platforms/powernv/opal-prd.c > +++ b/arch/powerpc/platforms/powernv/opal-prd.c > @@ -352,7 +352,9 @@ static int opal_prd_msg_notifier(struct notifier_block > *nb, > if (!item) > return -ENOMEM; > > - memcpy(&item->msg, msg->params, msg_size); > + item->msg = *hdr; > + hdr++; > + memcpy((char *)&item->msg + sizeof(*hdr), hdr, msg_size - > sizeof(*hdr)); > > spin_lock_irqsave(&opal_prd_msg_queue_lock, flags); > list_add_tail(&item->list, &opal_prd_msg_queue); > >
