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| author | Soenke Huster <soenke.huster@eknoes.de> | 2022-09-02 10:19:58 +0200 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2022-09-03 16:40:06 +0200 |
| commit | 8c0427842aaef161a38ac83b7e8d8fe050b4be04 (patch) | |
| tree | 992c5e13d7750c631cc86fb122ddfbf65cb8b7c6 /drivers | |
| parent | 69371801f929ff4b3c846a45b9d49db631897cd9 (diff) | |
| download | lwn-8c0427842aaef161a38ac83b7e8d8fe050b4be04.tar.gz lwn-8c0427842aaef161a38ac83b7e8d8fe050b4be04.zip | |
wifi: mac80211_hwsim: check length for virtio packets
An invalid packet with a length shorter than the specified length in the
netlink header can lead to use-after-frees and slab-out-of-bounds in the
processing of the netlink attributes, such as the following:
BUG: KASAN: slab-out-of-bounds in __nla_validate_parse+0x1258/0x2010
Read of size 2 at addr ffff88800ac7952c by task kworker/0:1/12
Workqueue: events hwsim_virtio_rx_work
Call Trace:
<TASK>
dump_stack_lvl+0x45/0x5d
print_report.cold+0x5e/0x5e5
kasan_report+0xb1/0x1c0
__nla_validate_parse+0x1258/0x2010
__nla_parse+0x22/0x30
hwsim_virtio_handle_cmd.isra.0+0x13f/0x2d0
hwsim_virtio_rx_work+0x1b2/0x370
process_one_work+0x8df/0x1530
worker_thread+0x575/0x11a0
kthread+0x29d/0x340
ret_from_fork+0x22/0x30
</TASK>
Discarding packets with an invalid length solves this.
Therefore, skb->len must be set at reception.
Change-Id: Ieaeb9a4c62d3beede274881a7c2722c6c6f477b6
Signed-off-by: Soenke Huster <soenke.huster@eknoes.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/wireless/mac80211_hwsim.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 6e55f153ff26..1f301a5fb396 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -5060,6 +5060,10 @@ static int hwsim_virtio_handle_cmd(struct sk_buff *skb) nlh = nlmsg_hdr(skb); gnlh = nlmsg_data(nlh); + + if (skb->len < nlh->nlmsg_len) + return -EINVAL; + err = genlmsg_parse(nlh, &hwsim_genl_family, tb, HWSIM_ATTR_MAX, hwsim_genl_policy, NULL); if (err) { @@ -5102,7 +5106,8 @@ static void hwsim_virtio_rx_work(struct work_struct *work) spin_unlock_irqrestore(&hwsim_virtio_lock, flags); skb->data = skb->head; - skb_set_tail_pointer(skb, len); + skb_reset_tail_pointer(skb); + skb_put(skb, len); hwsim_virtio_handle_cmd(skb); spin_lock_irqsave(&hwsim_virtio_lock, flags); |