From f9fff67d2d7ca6fa8066132003a3deef654c55b1 Mon Sep 17 00:00:00 2001

From: Nagarajan Maran <quic_nmaran@quicinc.com>

Date: Mon, 17 Apr 2023 13:35:02 +0300

Subject: [PATCH] wifi: ath11k: Fix SKB corruption in REO destination ring

Git-commit: f9fff67d2d7ca6fa8066132003a3deef654c55b1

Patch-mainline: v6.4-rc1

References: git-fixes

While running traffics for a long time, randomly an RX descriptor

filled with value "0" from REO destination ring is received.

This descriptor which is invalid causes the wrong SKB (SKB stored in

the IDR lookup with buffer id "0") to be fetched which in turn

causes SKB memory corruption issue and the same leads to crash

after some time.

Changed the start id for idr allocation to "1" and the buffer id "0"

is reserved for error validation. Introduced Sanity check to validate

the descriptor, before processing the SKB.

Crash Signature :

Unable to handle kernel paging request at virtual address 3f004900

PC points to "b15_dma_inv_range+0x30/0x50"

LR points to "dma_cache_maint_page+0x8c/0x128".

The Backtrace obtained is as follows:

[<8031716c>] (b15_dma_inv_range) from [<80313a4c>] (dma_cache_maint_page+0x8c/0x128)

[<80313a4c>] (dma_cache_maint_page) from [<80313b90>] (__dma_page_dev_to_cpu+0x28/0xcc)

[<80313b90>] (__dma_page_dev_to_cpu) from [<7fb5dd68>] (ath11k_dp_process_rx+0x1e8/0x4a4 [ath11k])

[<7fb5dd68>] (ath11k_dp_process_rx [ath11k]) from [<7fb53c20>] (ath11k_dp_service_srng+0xb0/0x2ac [ath11k])

[<7fb53c20>] (ath11k_dp_service_srng [ath11k]) from [<7f67bba4>] (ath11k_pci_ext_grp_napi_poll+0x1c/0x78 [ath11k_pci])

[<7f67bba4>] (ath11k_pci_ext_grp_napi_poll [ath11k_pci]) from [<807d5cf4>] (__napi_poll+0x28/0xb8)

[<807d5cf4>] (__napi_poll) from [<807d5f28>] (net_rx_action+0xf0/0x280)

[<807d5f28>] (net_rx_action) from [<80302148>] (__do_softirq+0xd0/0x280)

[<80302148>] (__do_softirq) from [<80320408>] (irq_exit+0x74/0xd4)

[<80320408>] (irq_exit) from [<803638a4>] (__handle_domain_irq+0x90/0xb4)

[<803638a4>] (__handle_domain_irq) from [<805bedec>] (gic_handle_irq+0x58/0x90)

[<805bedec>] (gic_handle_irq) from [<80301a78>] (__irq_svc+0x58/0x8c)

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.7.0.1-01744-QCAHKSWPL_SILICONZ-1

Signed-off-by: Nagarajan Maran <quic_nmaran@quicinc.com>

Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>

Link: https://lore.kernel.org/r/20230403191533.28114-1-quic_nmaran@quicinc.com

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/net/wireless/ath/ath11k/dp_rx.c | 9 ++++++---

 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c

index a4934bd79969..f67ce62b2b48 100644

--- a/drivers/net/wireless/ath/ath11k/dp_rx.c

+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c

@@ -389,10 +389,10 @@ int ath11k_dp_rxbufs_replenish(struct ath11k_base *ab, int mac_id,

 			goto fail_free_skb;

 		spin_lock_bh(&rx_ring->idr_lock);

-		buf_id = idr_alloc(&rx_ring->bufs_idr, skb, 0,

-				   rx_ring->bufs_max * 3, GFP_ATOMIC);

+		buf_id = idr_alloc(&rx_ring->bufs_idr, skb, 1,

+				   (rx_ring->bufs_max * 3) + 1, GFP_ATOMIC);

 		spin_unlock_bh(&rx_ring->idr_lock);

-		if (buf_id < 0)

+		if (buf_id <= 0)

 			goto fail_dma_unmap;

 		desc = ath11k_hal_srng_src_get_next_entry(ab, srng);

@@ -2665,6 +2665,9 @@ int ath11k_dp_process_rx(struct ath11k_base *ab, int ring_id,

 				   cookie);

 		mac_id = FIELD_GET(DP_RXDMA_BUF_COOKIE_PDEV_ID, cookie);

+		if (unlikely(buf_id == 0))

+			continue;

+

 		ar = ab->pdevs[mac_id].ar;

 		rx_ring = &ar->dp.rx_refill_buf_ring;

 		spin_lock_bh(&rx_ring->idr_lock);

-- 

2.35.3