diff options
| author |   Julian Wiedmann <jwi@linux.ibm.com> | 2021-11-26 18:55:43 +0100 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2021-11-26 11:17:47 -0800 |
| commit | 0276af2176c78771da7f311621a25d7608045827 (patch) | |
| tree | 06475cc9bb118ed3cdc85bc8ec51391df235f7b9 | |
| parent | nfc: virtual_ncidev: change default device permissions (diff) | |
| download | wireguard-linux-0276af2176c78771da7f311621a25d7608045827.tar.xz wireguard-linux-0276af2176c78771da7f311621a25d7608045827.zip | |
ethtool: ioctl: fix potential NULL deref in ethtool_set_coalesce()
ethtool_set_coalesce() now uses both the .get_coalesce() and
.set_coalesce() callbacks. But the check for their availability is
buggy, so changing the coalesce settings on a device where the driver
provides only _one_ of the callbacks results in a NULL pointer
dereference instead of an -EOPNOTSUPP.
Fix the condition so that the availability of both callbacks is
ensured. This also matches the netlink code.
Note that reproducing this requires some effort - it only affects the
legacy ioctl path, and needs a specific combination of driver options:
- have .get_coalesce() and .coalesce_supported but no
.set_coalesce(), or
- have .set_coalesce() but no .get_coalesce(). Here eg. ethtool doesn't
cause the crash as it first attempts to call ethtool_get_coalesce()
and bails out on error.
Fixes: f3ccfda19319 ("ethtool: extend coalesce setting uAPI with CQE mode")
Cc: Yufeng Mo <moyufeng@huawei.com>
Cc: Huazhong Tan <tanhuazhong@huawei.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Link: https://lore.kernel.org/r/20211126175543.28000-1-jwi@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ethtool/ioctl.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index 65e9bc1058b5..20bcf86970ff 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -1719,7 +1719,7 @@ static noinline_for_stack int ethtool_set_coalesce(struct net_device *dev, struct ethtool_coalesce coalesce; int ret; - if (!dev->ethtool_ops->set_coalesce && !dev->ethtool_ops->get_coalesce) + if (!dev->ethtool_ops->set_coalesce || !dev->ethtool_ops->get_coalesce) return -EOPNOTSUPP; ret = dev->ethtool_ops->get_coalesce(dev, &coalesce, &kernel_coalesce, |