2024-01-15 08:51:10

by Kunwu Chan

Subject: [PATCH net v2] net: phy: Fix possible NULL pointer dereference issues caused by phy_attached_info_irq

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.

phylink_bringup_phy needs to be done, otherwise network interface is
likely to be dead, so when irq_str is NULL, just print an empty string.

Fixes: e27f178793de ("net: phy: Added IRQ print to phylink_bringup_phy()")
Signed-off-by: Kunwu Chan <[email protected]>
Suggested-by: Andrew Lunn <[email protected]>
---
v2: Print empty string when irq_str is NULL in phylink_bringup_phy
---
drivers/net/phy/phy_device.c | 3 +++
drivers/net/phy/phylink.c | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 3611ea64875e..10fa99d957c0 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1299,6 +1299,9 @@ void phy_attached_print(struct phy_device *phydev, const char *fmt, ...)
const char *unbound = phydev->drv ? "" : "[unbound] ";
char *irq_str = phy_attached_info_irq(phydev);

+ if (!irq_str)
+ return;
+
if (!fmt) {
phydev_info(phydev, ATTACHED_FMT "\n", unbound,
phydev_name(phydev), irq_str);
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index ed0b4ccaa6a6..819574a06036 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -1886,7 +1886,7 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy,
irq_str = phy_attached_info_irq(phy);
phylink_info(pl,
"PHY [%s] driver [%s] (irq=%s)\n",
- dev_name(&phy->mdio.dev), phy->drv->name, irq_str);
+ dev_name(&phy->mdio.dev), phy->drv->name, irq_str ? irq_str : "");
kfree(irq_str);

mutex_lock(&phy->lock);
--
2.39.2

2024-01-15 11:28:51

by Russell King (Oracle)

Subject: Re: [PATCH net v2] net: phy: Fix possible NULL pointer dereference issues caused by phy_attached_info_irq

On Mon, Jan 15, 2024 at 04:50:18PM +0800, Kunwu Chan wrote:
> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index ed0b4ccaa6a6..819574a06036 100644
> --- a/drivers/net/phy/phylink.c
> +++ b/drivers/net/phy/phylink.c
> @@ -1886,7 +1886,7 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy,
> irq_str = phy_attached_info_irq(phy);
> phylink_info(pl,
> "PHY [%s] driver [%s] (irq=%s)\n",
> - dev_name(&phy->mdio.dev), phy->drv->name, irq_str);
> + dev_name(&phy->mdio.dev), phy->drv->name, irq_str ? irq_str : "");


dev_name(&phy->mdio.dev), phy->drv->name,
irq_str ? irq_str : "");

please.

Also, please hold off posting v3 until at least 24 hours have passed.

Thanks.

--
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