The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x aa6956150f820e6a6deba44be325ddfcb5b10f88 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025082143-halved-suitably-b32b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From aa6956150f820e6a6deba44be325ddfcb5b10f88 Mon Sep 17 00:00:00 2001 From: Johan Hovold johan+linaro@kernel.org Date: Wed, 4 Jun 2025 16:34:57 +0200 Subject: [PATCH] wifi: ath11k: fix dest ring-buffer corruption when ring is full
Add the missing memory barriers to make sure that destination ring descriptors are read before updating the tail pointer (and passing ownership to the device) to avoid memory corruption on weakly ordered architectures like aarch64 when the ring is full.
Tested-on: WCN6855 hw2.1 WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.41
Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices") Cc: stable@vger.kernel.org # 5.6 Signed-off-by: Johan Hovold johan+linaro@kernel.org Reviewed-by: Baochen Qiang quic_bqiang@quicinc.com Link: https://patch.msgid.link/20250604143457.26032-6-johan+linaro@kernel.org Signed-off-by: Jeff Johnson jeff.johnson@oss.qualcomm.com
diff --git a/drivers/net/wireless/ath/ath11k/hal.c b/drivers/net/wireless/ath/ath11k/hal.c index 28f94c36d304..0c3ce7509ab8 100644 --- a/drivers/net/wireless/ath/ath11k/hal.c +++ b/drivers/net/wireless/ath/ath11k/hal.c @@ -856,7 +856,6 @@ void ath11k_hal_srng_access_end(struct ath11k_base *ab, struct hal_srng *srng) { lockdep_assert_held(&srng->lock);
- /* TODO: See if we need a write memory barrier here */ if (srng->flags & HAL_SRNG_FLAGS_LMAC_RING) { /* For LMAC rings, ring pointer updates are done through FW and * hence written to a shared memory location that is read by FW @@ -871,7 +870,11 @@ void ath11k_hal_srng_access_end(struct ath11k_base *ab, struct hal_srng *srng) WRITE_ONCE(*srng->u.src_ring.hp_addr, srng->u.src_ring.hp); } else { srng->u.dst_ring.last_hp = *srng->u.dst_ring.hp_addr; - *srng->u.dst_ring.tp_addr = srng->u.dst_ring.tp; + /* Make sure descriptor is read before updating the + * tail pointer. + */ + dma_mb(); + WRITE_ONCE(*srng->u.dst_ring.tp_addr, srng->u.dst_ring.tp); } } else { if (srng->ring_dir == HAL_SRNG_DIR_SRC) { @@ -887,6 +890,10 @@ void ath11k_hal_srng_access_end(struct ath11k_base *ab, struct hal_srng *srng) srng->u.src_ring.hp); } else { srng->u.dst_ring.last_hp = *srng->u.dst_ring.hp_addr; + /* Make sure descriptor is read before updating the + * tail pointer. + */ + mb(); ath11k_hif_write32(ab, (unsigned long)srng->u.dst_ring.tp_addr - (unsigned long)ab->mem,