From 84bb0ac6c86f705af253789d382a684759cb2d72 Mon Sep 17 00:00:00 2001 From: Alexander Usyskin Date: Tue, 8 Mar 2022 11:59:26 +0200 Subject: [PATCH] mei: avoid iterator usage outside of list_for_each_entry commit c10187b1c5ebb8681ca467ab7b0ded5ea415d258 upstream. Usage of the iterator outside of the list_for_each_entry is considered harmful. https://lkml.org/lkml/2022/2/17/1032 Do not reference the loop variable outside of the loop, by rearranging the orders of execution. Instead of performing search loop and checking outside the loop if the end of the list was hit and no matching element was found, the execution is performed inside the loop upon a successful match followed by a goto statement to the next step, therefore no condition has to be performed after the loop has ended. Cc: Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Link: https://lore.kernel.org/r/20220308095926.300412-1-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/interrupt.c | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c index a67f4f2..0706322 100644 --- a/drivers/misc/mei/interrupt.c +++ b/drivers/misc/mei/interrupt.c @@ -424,31 +424,26 @@ int mei_irq_read_handler(struct mei_device *dev, list_for_each_entry(cl, &dev->file_list, link) { if (mei_cl_hbm_equal(cl, mei_hdr)) { cl_dbg(dev, cl, "got a message\n"); - break; + ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list); + goto reset_slots; } } /* if no recipient cl was found we assume corrupted header */ - if (&cl->link == &dev->file_list) { - /* A message for not connected fixed address clients - * should be silently discarded - * On power down client may be force cleaned, - * silently discard such messages - */ - if (hdr_is_fixed(mei_hdr) || - dev->dev_state == MEI_DEV_POWER_DOWN) { - mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length); - ret = 0; - goto reset_slots; - } - dev_err(dev->dev, "no destination client found 0x%08X\n", - dev->rd_msg_hdr[0]); - ret = -EBADMSG; - goto end; + /* A message for not connected fixed address clients + * should be silently discarded + * On power down client may be force cleaned, + * silently discard such messages + */ + if (hdr_is_fixed(mei_hdr) || + dev->dev_state == MEI_DEV_POWER_DOWN) { + mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length); + ret = 0; + goto reset_slots; } - - ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list); - + dev_err(dev->dev, "no destination client found 0x%08X\n", dev->rd_msg_hdr[0]); + ret = -EBADMSG; + goto end; reset_slots: /* reset the number of slots and header */ -- 2.7.4