From: Jakob Koschel jkl820.git@gmail.com
[ 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=EHreAsk5SqXPwr9Y7k9sA6cWX... [1] Signed-off-by: Jakob Koschel jkl820.git@gmail.com Link: https://lore.kernel.org/r/20230301-scsi-lpfc-avoid-list-iterator-after-loop-... Reviewed-by: Justin Tee justin.tee@broadcom.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/lpfc/lpfc_sli.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 755d68b981602..923ceaba0bf30 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -20816,20 +20816,20 @@ 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; } }