diff mbox series

[net-next] net: phylink: don't call netif_carrier_off() with NULL netdev

Message ID E1mRE2Z-001xhc-CB@rmk-PC.armlinux.org.uk (mailing list archive)
State Accepted
Commit cbcca2e3961eac736566ac13ef0d0bf6f0b764ec
Delegated to: Netdev Maintainers
Headers show
Series [net-next] net: phylink: don't call netif_carrier_off() with NULL netdev | expand

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netdev/tree_selection success Clearly marked for net-next
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netdev/cc_maintainers warning 1 maintainers not CCed: linux@armlinux.org.uk
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 11 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link

Commit Message

Russell King (Oracle) Sept. 17, 2021, 1:36 p.m. UTC
Dan Carpenter points out that we have a code path that permits a NULL
netdev pointer to be passed to netif_carrier_off(), which will cause
a kernel oops. In any case, we need to set pl->old_link_state to false
to have the desired effect when there is no netdev present.

Fixes: f97493657c63 ("net: phylink: add suspend/resume support")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
This does not need to be queued for -rc as there is only one user of
phylink_suspend(), which will always have a non-NULL netdev pointer.
Hence, submitting for net-next is appropriate.

 drivers/net/phy/phylink.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

patchwork-bot+netdevbpf@kernel.org Sept. 19, 2021, 12:30 p.m. UTC | #1
Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Fri, 17 Sep 2021 14:36:31 +0100 you wrote:
> Dan Carpenter points out that we have a code path that permits a NULL
> netdev pointer to be passed to netif_carrier_off(), which will cause
> a kernel oops. In any case, we need to set pl->old_link_state to false
> to have the desired effect when there is no netdev present.
> 
> Fixes: f97493657c63 ("net: phylink: add suspend/resume support")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> 
> [...]

Here is the summary with links:
  - [net-next] net: phylink: don't call netif_carrier_off() with NULL netdev
    https://git.kernel.org/netdev/net-next/c/cbcca2e3961e

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 0a0abe8e4be0..5a58c77d0002 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -1333,7 +1333,10 @@  void phylink_suspend(struct phylink *pl, bool mac_wol)
 		 * but one would hope all packets have been sent. This
 		 * also means phylink_resolve() will do nothing.
 		 */
-		netif_carrier_off(pl->netdev);
+		if (pl->netdev)
+			netif_carrier_off(pl->netdev);
+		else
+			pl->old_link_state = false;
 
 		/* We do not call mac_link_down() here as we want the
 		 * link to remain up to receive the WoL packets.