diff mbox series

[net] net: phy: fix phy_read_poll_timeout argument type in genphy_loopback

Message ID 031a0fe6-79dc-464b-b8d9-946f75971378@ancud.ru (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [net] net: phy: fix phy_read_poll_timeout argument type in genphy_loopback | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/apply fail Patch does not apply to net-0

Commit Message

Nikita Kiryushin March 14, 2024, 11:15 a.m. UTC
read_poll_timeout inside phy_read_poll_timeout can set val negative
in some cases (for example, __mdiobus_read inside phy_read can return
-EOPNOTSUPP).

Supposedly, commit 4ec732951702 ("net: phylib: fix phy_read*_poll_timeout()")
should fix problems with wrong-signed vals, but I do not see how
as val is sent to phy_read as is and __val = phy_read (not val)
is checked for sign.

Change val type for signed to allow better error handling as done in other
phy_read_poll_timeout callers. This will not fix any error handling
by itself, but allows, for example, to modify cond with appropriate
sign check or check resulting val separately.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 014068dcb5b1 ("net: phy: genphy_loopback: add link speed configuration")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
---
  drivers/net/phy/phy_device.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Jakub Kicinski March 14, 2024, 11:48 p.m. UTC | #1
On Thu, 14 Mar 2024 14:15:37 +0300 Nikita Kiryushin wrote:
> read_poll_timeout inside phy_read_poll_timeout can set val negative
> in some cases (for example, __mdiobus_read inside phy_read can return
> -EOPNOTSUPP).
> 
> Supposedly, commit 4ec732951702 ("net: phylib: fix phy_read*_poll_timeout()")
> should fix problems with wrong-signed vals, but I do not see how
> as val is sent to phy_read as is and __val = phy_read (not val)
> is checked for sign.
> 
> Change val type for signed to allow better error handling as done in other
> phy_read_poll_timeout callers. This will not fix any error handling
> by itself, but allows, for example, to modify cond with appropriate
> sign check or check resulting val separately.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 014068dcb5b1 ("net: phy: genphy_loopback: add link speed configuration")
> Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>

Please use git send email, the patch is mangled.
diff mbox series

Patch

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 8297ef681bf5..6c6ec9475709 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -2831,8 +2831,8 @@  EXPORT_SYMBOL(genphy_resume);
  int genphy_loopback(struct phy_device *phydev, bool enable)
  {
  	if (enable) {
-		u16 val, ctl = BMCR_LOOPBACK;
-		int ret;
+		u16 ctl = BMCR_LOOPBACK;
+		int ret, val;
  
  		ctl |= mii_bmcr_encode_fixed(phydev->speed, phydev->duplex);