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| author | Sven Eckelmann <sven@narfation.org> | 2018-08-31 16:46:47 +0200 |
|---|---|---|
| committer | Simon Wunderlich <sw@simonwunderlich.de> | 2018-09-06 13:54:48 +0200 |
| commit | b9fd14c20871e6189f635e49b32d7789e430b3c8 (patch) | |
| tree | a46655018ceb528b5d10866d48ea7415673feae9 /net/batman-adv/sysfs.c | |
| parent | 88d0895d0ea9d4431507d576c963f2ff9918144d (diff) | |
| download | lwn-b9fd14c20871e6189f635e49b32d7789e430b3c8.tar.gz lwn-b9fd14c20871e6189f635e49b32d7789e430b3c8.zip | |
batman-adv: Fix segfault when writing to throughput_override
The per hardif sysfs file "batman_adv/throughput_override" prints the
resulting change as info text when the users writes to this file. It uses
the helper function batadv_info to add it at the same time to the kernel
ring buffer and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG
is enabled).
The function batadv_info requires as first parameter the batman-adv softif
net_device. This parameter is then used to find the private buffer which
contains the debug log for this batman-adv interface. But
batadv_store_throughput_override used as first argument the slave
net_device. This slave device doesn't have the batadv_priv private data
which is access by batadv_info.
Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead
to a segfault or to memory corruption.
Fixes: 0b5ecc6811bd ("batman-adv: add throughput override attribute to hard_ifaces")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Diffstat (limited to 'net/batman-adv/sysfs.c')
| -rw-r--r-- | net/batman-adv/sysfs.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index f2eef43bd2ec..3a76e8970c02 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -1090,8 +1090,9 @@ static ssize_t batadv_store_throughput_override(struct kobject *kobj, if (old_tp_override == tp_override) goto out; - batadv_info(net_dev, "%s: Changing from: %u.%u MBit to: %u.%u MBit\n", - "throughput_override", + batadv_info(hard_iface->soft_iface, + "%s: %s: Changing from: %u.%u MBit to: %u.%u MBit\n", + "throughput_override", net_dev->name, old_tp_override / 10, old_tp_override % 10, tp_override / 10, tp_override % 10); |