In case of buggy firmware, brcmfmac may perform a hardware reset. If during
reset and subsequent probing an early failure occurs, a memory region is
accidentally double-freed. With hardened memory allocation enabled, this error
will be detected.
- return early where appropriate to skip unnecessary clean-up.
- set '.freezer' pointer to NULL to prevent double-freeing under possible
other circumstances and to re-align result under various different
behaviors of memory allocation freeing.
- correctly claim host on func1 for disabling func2.
- after reset, do not initiate probing immediately, but rely on events.
Given a firmware crash, function 'brcmf_sdio_bus_reset' is called. It calls
'brcmf_sdiod_remove', then follows up with 'brcmf_sdiod_probe' to reinitialize
the hardware. If 'brcmf_sdiod_probe' fails to "set F1 blocksize", it exits
early, which includes calling 'brcmf_sdiod_remove'. In both cases
'brcmf_sdiod_freezer_detach' is called to free allocated '.freezer', which
has not yet been re-allocated the second time.
Stacktrace of (failing) hardware reset after firmware-crash:
Code: b9402b82 8b0202c0 eb1a02df 54000041 (d4210000)
ret_from_fork+0x10/0x20
kthread+0x154/0x160
worker_thread+0x188/0x504
process_one_work+0x1f4/0x490
brcmf_core_bus_reset+0x34/0x44 [brcmfmac]
brcmf_sdio_bus_reset+0x68/0xc0 [brcmfmac]
brcmf_sdiod_probe+0x170/0x21c [brcmfmac]
brcmf_sdiod_remove+0x48/0xc0 [brcmfmac]
kfree+0x210/0x220
__slab_free+0x58/0x40c
Call trace:
x2 : 0000000000000040 x1 : fffffc00002d2b80 x0 : ffff00000b4aee40
x5 : ffff8000013fa728 x4 : 0000000000000001 x3 : ffff00000b4aee00
x8 : ffff800009967ce0 x7 : ffff8000099bfce0 x6 : 00000006f8005d01
x11: ffff8000099bfce0 x10: 00000000fffff000 x9 : ffff8000083401d0
x14: 0000000000000000 x13: 657a69736b636f6c x12: 6220314620746573
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000030
x20: fffffc00002d2ba0 x19: fffffc00002d2b80 x18: 0000000000000000
x23: ffff00000b4aee00 x22: ffff00000b4aee00 x21: 0000000000000001
x26: ffff00000b4aee00 x25: ffff0000f7753705 x24: 000000000001288a
x29: ffff80000a22bbf0 x28: ffff000000401200 x27: 000000008020001a
sp : ffff80000a22bbf0
lr : kfree+0x210/0x220
pc : __slab_free+0x58/0x40c
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
Workqueue: events brcmf_core_bus_reset [brcmfmac]
Hardware name: Pine64 Pinebook Pro (DT)
CPU: 2 PID: 639 Comm: kworker/2:2 Tainted: G C 5.16.0-0.bpo.4-arm64 #1 Debian 5.16.12-1~bpo11+1
nvmem_rockchip_efuse industrialio_triggered_buffer videodev snd_soc_core snd_pcm_dmaengine kfifo_buf snd_pcm io_domain mc industrialio mt>
Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reje>
Internal error: Oops - BUG: 0 [#1] SMP
kernel BUG at mm/slub.c:379!
Signed-off-by: Danny van Heumen <danny@xxxxxxxxxxxxxxxxx>
---
.../broadcom/brcm80211/brcmfmac/bcmsdh.c | 31 ++++++++++++-------
.../broadcom/brcm80211/brcmfmac/sdio.c | 10 +-----
2 files changed, 21 insertions(+), 20 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
index ac02244a6fdf..dd634edaa0b3 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c
@@ -802,6 +802,7 @@ static void brcmf_sdiod_freezer_detach(struct brcmf_sdio_dev *sdiodev)
if (sdiodev->freezer) {
WARN_ON(atomic_read(&sdiodev->freezer->freezing));
kfree(sdiodev->freezer);
+ sdiodev->freezer = NULL;
}
}
@@ -875,13 +876,9 @@ int brcmf_sdiod_remove(struct brcmf_sdio_dev *sdiodev)
brcmf_sdiod_freezer_detach(sdiodev);
- /* Disable Function 2 */
- sdio_claim_host(sdiodev->func2);
- sdio_disable_func(sdiodev->func2);
- sdio_release_host(sdiodev->func2);
-
- /* Disable Function 1 */
+ /* Disable functions 2 then 1. */
sdio_claim_host(sdiodev->func1);
+ sdio_disable_func(sdiodev->func2);
sdio_disable_func(sdiodev->func1);
sdio_release_host(sdiodev->func1);
@@ -911,7 +908,7 @@ int brcmf_sdiod_probe(struct brcmf_sdio_dev *sdiodev)
if (ret) {
brcmf_err("Failed to set F1 blocksize\n");
sdio_release_host(sdiodev->func1);
- goto out;
+ return ret;
}
switch (sdiodev->func2->device) {
case SDIO_DEVICE_ID_BROADCOM_CYPRESS_4373:
@@ -933,7 +930,7 @@ int brcmf_sdiod_probe(struct brcmf_sdio_dev *sdiodev)
if (ret) {
brcmf_err("Failed to set F2 blocksize\n");
sdio_release_host(sdiodev->func1);
- goto out;
+ return ret;
} else {
brcmf_dbg(SDIO, "set F2 blocksize to %d\n", f2_blksz);
}
@@ -1096,12 +1093,24 @@ static void brcmf_ops_sdio_remove(struct sdio_func *func)
if (bus_if) {
sdiodev = bus_if->bus_priv.sdio;
+ if (func->num != 1) {
+ /* Satisfy kernel expectation that the irq is released once the
+ * '.remove' callback has executed, while respecting the design
+ * that removal is executed for 'sdiodev', instead of individual
+ * function.
+ */
+ brcmf_dbg(SDIO, "Only release irq for function %d", func->num);
+ sdio_claim_host(sdiodev->func1);
+ sdio_release_irq(func);
+ sdio_release_host(sdiodev->func1);
+ return;
+ }
+
+ /* func 1: so do full clean-up and removal */
+
/* start by unregistering irqs */
brcmf_sdiod_intr_unregister(sdiodev);
- if (func->num != 1)
- return;
-
/* only proceed with rest of cleanup if func 1 */
brcmf_sdiod_remove(sdiodev);
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
index 212fbbe1cd7e..2ed70f809097 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
@@ -4152,7 +4152,6 @@ int brcmf_sdio_get_fwname(struct device *dev, const char *ext, u8 *fw_name)
static int brcmf_sdio_bus_reset(struct device *dev)
{
- int ret = 0;
struct brcmf_bus *bus_if = dev_get_drvdata(dev);
struct brcmf_sdio_dev *sdiodev = bus_if->bus_priv.sdio;
@@ -4169,14 +4168,7 @@ static int brcmf_sdio_bus_reset(struct device *dev)
sdio_release_host(sdiodev->func1);
brcmf_bus_change_state(sdiodev->bus_if, BRCMF_BUS_DOWN);
-
- ret = brcmf_sdiod_probe(sdiodev);
- if (ret) {
- brcmf_err("Failed to probe after sdio device reset: ret %d\n",
- ret);
- }
-
- return ret;
+ return 0;
}
static const struct brcmf_bus_ops brcmf_sdio_bus_ops = {
--
2.34.1
