diff mbox series

[v6,1/9] libata: fix ata_host_alloc_pinfo()

Message ID 20210812024403.765819-2-damien.lemoal@wdc.com (mailing list archive)
State New, archived
Headers show
Series libata cleanups and improvements | expand

Commit Message

Damien Le Moal Aug. 12, 2021, 2:43 a.m. UTC
Avoid static checkers warnings about a potential NULL pointer
dereference for the port info variable pi. To do so, test that at least
one port info is available on entry to ata_host_alloc_pinfo() and start
the ata port initialization for() loop with pi initialized to the first
port info passed as argument (which is already checked to be non NULL).
Within the for() loop, get the next port info, if it is not NULL,
after initializing the ata port using the previous port info.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
---
 drivers/ata/libata-core.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 61c762961ca8..b237a718ea0f 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5441,16 +5441,17 @@  struct ata_host *ata_host_alloc_pinfo(struct device *dev,
 	struct ata_host *host;
 	int i, j;
 
+	/* We must have at least one port info */
+	if (!ppi[0])
+		return NULL;
+
 	host = ata_host_alloc(dev, n_ports);
 	if (!host)
 		return NULL;
 
-	for (i = 0, j = 0, pi = NULL; i < host->n_ports; i++) {
+	for (i = 0, j = 0, pi = ppi[0]; i < host->n_ports; i++) {
 		struct ata_port *ap = host->ports[i];
 
-		if (ppi[j])
-			pi = ppi[j++];
-
 		ap->pio_mask = pi->pio_mask;
 		ap->mwdma_mask = pi->mwdma_mask;
 		ap->udma_mask = pi->udma_mask;
@@ -5460,6 +5461,15 @@  struct ata_host *ata_host_alloc_pinfo(struct device *dev,
 
 		if (!host->ops && (pi->port_ops != &ata_dummy_port_ops))
 			host->ops = pi->port_ops;
+
+		/*
+		 * Check that the next port info is not NULL.
+		 * If it is, keep using the current one.
+		 */
+		if (j < n_ports - 1 && ppi[j + 1]) {
+			j++;
+			pi = ppi[j];
+		}
 	}
 
 	return host;