Skip to content

wireguardif: route decrypted RX through netif->input, not ip_input() (fixes pbuf double-free crash) #20

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
snowpaper wants to merge 1 commit into
base: main
Choose a base branch
from
Open

wireguardif: route decrypted RX through netif->input, not ip_input() (fixes pbuf double-free crash) #20

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
11 changes: 8 additions & 3 deletions components/microlink/components/wireguard_lwip/src/wireguardif.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -539,9 +539,14 @@ static void wireguardif_process_data_message(struct wireguard_device *device, st
if (dest_ok) {
// Send packet to be processed by LWIP
WG_DEBUG("[WG_RX_IP] Passing %u bytes to IP layer\n", (unsigned)pbuf->tot_len);
ip_input(pbuf, device->netif);
// pbuf is owned by IP layer now
pbuf = NULL;
// Enter the lwIP core ONLY from the tcpip_thread. netif->input is
// tcpip_input (set in ml_wg_mgr): posting the packet defers ip_input
// to the tcpip_thread. Calling ip_input() directly here runs on the
// wg_mgr task and races the tcpip_thread's WiFi TCP processing ->
// unsynchronized pbuf/PCB access -> double-free crash (pbuf.c:753).
if (device->netif->input(pbuf, device->netif) == ERR_OK) {
pbuf = NULL; // ownership handed to the tcpip_thread queue
} // else: still ours -> freed by pbuf_free() at the end of this block
} else {
WG_DEBUG("[WG_RX_IP] DROPPED: dest_ok=false\n");
}
Expand Down