[rp2040] Fix W5500 Ethernet pbuf corruption by mirroring LWIPMutex semantics (#15624)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
This commit is contained in:
J. Nick Koston
2026-04-10 13:13:05 -10:00
committed by GitHub
parent a7c5b0ab46
commit 40081e5ae7

View File

@@ -9,7 +9,7 @@
#include <WiFi.h>
#include <pico/cyw43_arch.h> // For cyw43_arch_lwip_begin/end (LwIPLock)
#elif defined(USE_ETHERNET)
#include <LwipEthernet.h> // For ethernet_arch_lwip_begin/end (LwIPLock)
#include <lwip_wrap.h> // For LWIPMutex — LwIPLock mirrors its semantics (see below)
#include "esphome/components/ethernet/ethernet_component.h"
#endif
#include <hardware/structs/rosc.h>
@@ -43,9 +43,18 @@ IRAM_ATTR InterruptLock::~InterruptLock() { restore_interrupts(state_); }
// main loop, corrupting the shared rx_buf_ pbuf chain (use-after-free, pbuf_cat
// assertion failures). See esphome#10681.
//
// WiFi uses cyw43_arch_lwip_begin/end; Ethernet uses ethernet_arch_lwip_begin/end.
// Both acquire the async_context recursive mutex to prevent IRQ callbacks from
// firing during critical sections.
// WiFi uses cyw43_arch_lwip_begin/end.
//
// For wired Ethernet, taking only the async_context lock is NOT enough. The
// W5500 GPIO IRQ path (LwipIntfDev::_irq) checks arduino-pico's `__inLWIP`
// counter to decide whether to defer packet processing. If we hold the
// async_context lock without bumping `__inLWIP`, an interrupt-driven packet
// arrival re-enters lwIP from IRQ context and corrupts pbufs (the `pbuf_cat`
// assertion crash on wiznet-w5500-evb-pico). We mirror arduino-pico's
// LWIPMutex (cores/rp2040/lwip_wrap.h) exactly: bump `__inLWIP`, take the
// lock, and on release re-unmask any GPIO IRQs that were deferred while we
// held it. We can't `using LwIPLock = LWIPMutex;` in helpers.h because
// pulling lwip_wrap.h there poisons many TUs with lwIP types.
//
// When neither WiFi nor Ethernet is configured, this is a no-op since
// there's no network stack and no lwip callbacks to race with.
@@ -53,8 +62,18 @@ IRAM_ATTR InterruptLock::~InterruptLock() { restore_interrupts(state_); }
LwIPLock::LwIPLock() { cyw43_arch_lwip_begin(); }
LwIPLock::~LwIPLock() { cyw43_arch_lwip_end(); }
#elif defined(USE_ETHERNET)
LwIPLock::LwIPLock() { ethernet_arch_lwip_begin(); }
LwIPLock::~LwIPLock() { ethernet_arch_lwip_end(); }
LwIPLock::LwIPLock() {
__inLWIP++;
ethernet_arch_lwip_begin();
}
LwIPLock::~LwIPLock() {
ethernet_arch_lwip_end();
__inLWIP--;
if (__needsIRQEN && !__inLWIP) {
__needsIRQEN = false;
ethernet_arch_lwip_gpio_unmask();
}
}
#else
LwIPLock::LwIPLock() {}
LwIPLock::~LwIPLock() {}