From: Jakob Koschel Date: Wed, 1 Mar 2023 17:19:14 +0000 (+0100) Subject: scsi: lpfc: Avoid usage of list iterator variable after loop X-Git-Tag: baikal/mips/sdk5.8.2~68 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=777ed4bbe3eaa3a63de4c884cea655c4b81c6440;p=kernel.git scsi: lpfc: Avoid usage of list iterator variable after loop [ Upstream commit 2850b23e9f9ae3696e472d2883ea1b43aafa884e ] If the &epd_pool->list is empty when executing lpfc_get_io_buf_from_expedite_pool() the function would return an invalid pointer. Even in the case if the list is guaranteed to be populated, the iterator variable should not be used after the loop to be more robust for future changes. Linus proposed to avoid any use of the list iterator variable after the loop, in the attempt to move the list iterator variable declaration into the macro to avoid any potential misuse after the loop [1]. Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Signed-off-by: Jakob Koschel Link: https://lore.kernel.org/r/20230301-scsi-lpfc-avoid-list-iterator-after-loop-v1-1-325578ae7561@gmail.com Reviewed-by: Justin Tee Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index bd908dd273078..e489c68cfb631 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -20407,20 +20407,20 @@ lpfc_get_io_buf_from_private_pool(struct lpfc_hba *phba, static struct lpfc_io_buf * lpfc_get_io_buf_from_expedite_pool(struct lpfc_hba *phba) { - struct lpfc_io_buf *lpfc_ncmd; + struct lpfc_io_buf *lpfc_ncmd = NULL, *iter; struct lpfc_io_buf *lpfc_ncmd_next; unsigned long iflag; struct lpfc_epd_pool *epd_pool; epd_pool = &phba->epd_pool; - lpfc_ncmd = NULL; spin_lock_irqsave(&epd_pool->lock, iflag); if (epd_pool->count > 0) { - list_for_each_entry_safe(lpfc_ncmd, lpfc_ncmd_next, + list_for_each_entry_safe(iter, lpfc_ncmd_next, &epd_pool->list, list) { - list_del(&lpfc_ncmd->list); + list_del(&iter->list); epd_pool->count--; + lpfc_ncmd = iter; break; } }