diff options
| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2025-04-15 00:28:50 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-04-16 18:14:43 -0700 |
| commit | c84f6ce918a9e6f4996597cbc62536bbf2247c96 (patch) | |
| tree | acb9ef85fd2e6e2cde83b7d2435e3a7dfd19cc7f | |
| parent | b2727326d0a53709380aa147018085d71a6d4843 (diff) | |
net: dsa: mv88e6xxx: avoid unregistering devlink regions which were never registered
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>
| -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 795c8df7b6a7..195460a0a0d4 100644 --- a/drivers/net/dsa/mv88e6xxx/devlink.c +++ b/drivers/net/dsa/mv88e6xxx/devlink.c @@ -736,7 +736,8 @@ 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) |