diff options
| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2025-04-15 00:28:50 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-25 10:47:45 +0200 |
| commit | 3665695e3572239dc233216f06b41f40cc771889 (patch) | |
| tree | 02c128aa35de297d74d0595d3b55277396902822 | |
| parent | 635863d93deb8e352d63a8eba852efeaf1ac3539 (diff) | |
net: dsa: mv88e6xxx: avoid unregistering devlink regions which were never registered
[ Upstream commit c84f6ce918a9e6f4996597cbc62536bbf2247c96 ]
Russell King reports that a system with mv88e6xxx dereferences a NULL
pointer when unbinding this driver:
https://lore.kernel.org/netdev/Z_lRkMlTJ1KQ0kVX@shell.armlinux.org.uk/
The crash seems to be in devlink_region_destroy(), which is not NULL
tolerant but is given a NULL devlink global region pointer.
At least on some chips, some devlink regions are conditionally registered
since the blamed commit, see mv88e6xxx_setup_devlink_regions_global():
if (cond && !cond(chip))
continue;
These are MV88E6XXX_REGION_STU and MV88E6XXX_REGION_PVT. If the chip
does not have an STU or PVT, it should crash like this.
To fix the issue, avoid unregistering those regions which are NULL, i.e.
were skipped at mv88e6xxx_setup_devlink_regions_global() time.
Fixes: 836021a2d0e0 ("net: dsa: mv88e6xxx: Export cross-chip PVT as devlink region")
Tested-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20250414212850.2953957-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/net/dsa/mv88e6xxx/devlink.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/dsa/mv88e6xxx/devlink.c b/drivers/net/dsa/mv88e6xxx/devlink.c index a08dab75e0c0..f57fde02077d 100644 --- a/drivers/net/dsa/mv88e6xxx/devlink.c +++ b/drivers/net/dsa/mv88e6xxx/devlink.c @@ -743,7 +743,8 @@ void mv88e6xxx_teardown_devlink_regions_global(struct dsa_switch *ds) int i; for (i = 0; i < ARRAY_SIZE(mv88e6xxx_regions); i++) - dsa_devlink_region_destroy(chip->regions[i]); + if (chip->regions[i]) + dsa_devlink_region_destroy(chip->regions[i]); } void mv88e6xxx_teardown_devlink_regions_port(struct dsa_switch *ds, int port) |