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authorSven Eckelmann <sven@narfation.org>2018-08-31 16:46:47 +0200
committerSimon Wunderlich <sw@simonwunderlich.de>2018-09-06 13:54:48 +0200
commitb9fd14c20871e6189f635e49b32d7789e430b3c8 (patch)
treea46655018ceb528b5d10866d48ea7415673feae9 /net/batman-adv
parent88d0895d0ea9d4431507d576c963f2ff9918144d (diff)
downloadlinux-b9fd14c20871e6189f635e49b32d7789e430b3c8.tar.bz2
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')
-rw-r--r--net/batman-adv/sysfs.c5
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);