6.6-stable review patch. If anyone has any objections, please let me know.
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From: Greg Ungerer gerg@kernel.org
[ Upstream commit a524eabcd72d28425d9db242cf375d0389d74eba ]
As of commit b92143d4420f ("net: dsa: mv88e6xxx: add infrastructure for phylink_pcs") probing of a Marvell 88e6350 switch causes a NULL pointer de-reference like this example:
... mv88e6085 d0072004.mdio-mii:11: switch 0x3710 detected: Marvell 88E6350, revision 2 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] ARM Modules linked in: CPU: 0 PID: 8 Comm: kworker/u2:0 Not tainted 6.7.0-rc2-dirty #26 Hardware name: Marvell Armada 370/XP (Device Tree) Workqueue: events_unbound deferred_probe_work_func PC is at mv88e6xxx_port_setup+0x1c/0x44 LR is at dsa_port_devlink_setup+0x74/0x154 pc : [<c057ea24>] lr : [<c0819598>] psr: a0000013 sp : c184fce0 ip : c542b8f4 fp : 00000000 r10: 00000001 r9 : c542a540 r8 : c542bc00 r7 : c542b838 r6 : c5244580 r5 : 00000005 r4 : c5244580 r3 : 00000000 r2 : c542b840 r1 : 00000005 r0 : c1a02040 ...
The Marvell 6350 switch has no SERDES interface and so has no corresponding pcs_ops defined for it. But during probing a call is made to mv88e6xxx_port_setup() which unconditionally expects pcs_ops to exist - though the presence of the pcs_ops->pcs_init function is optional.
Modify code to check for pcs_ops first, before checking for and calling pcs_ops->pcs_init. Modify checking and use of pcs_ops->pcs_teardown which may potentially suffer the same problem.
Fixes: b92143d4420f ("net: dsa: mv88e6xxx: add infrastructure for phylink_pcs") Signed-off-by: Greg Ungerer gerg@kernel.org Reviewed-by: Andrew Lunn andrew@lunn.ch Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/dsa/mv88e6xxx/chip.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c index 6d7256ea477a1..dc7f9b99f409f 100644 --- a/drivers/net/dsa/mv88e6xxx/chip.c +++ b/drivers/net/dsa/mv88e6xxx/chip.c @@ -3892,7 +3892,8 @@ static int mv88e6xxx_port_setup(struct dsa_switch *ds, int port) struct mv88e6xxx_chip *chip = ds->priv; int err;
- if (chip->info->ops->pcs_ops->pcs_init) { + if (chip->info->ops->pcs_ops && + chip->info->ops->pcs_ops->pcs_init) { err = chip->info->ops->pcs_ops->pcs_init(chip, port); if (err) return err; @@ -3907,7 +3908,8 @@ static void mv88e6xxx_port_teardown(struct dsa_switch *ds, int port)
mv88e6xxx_teardown_devlink_regions_port(ds, port);
- if (chip->info->ops->pcs_ops->pcs_teardown) + if (chip->info->ops->pcs_ops && + chip->info->ops->pcs_ops->pcs_teardown) chip->info->ops->pcs_ops->pcs_teardown(chip, port); }