dmaengine: ti: k3-udma-glue: Drop skip_fdq argument from k3_udma_glue_reset_rx_chn
CVE: CVE-2025-38042
Component: kernel
CWE: CWE-20
Severity: Low
CVSS v3: 5.6/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Release date: 2025-06-18T00:00:00+00:00

In the Linux kernel, the following vulnerability has been resolved:

dmaengine: ti: k3-udma-glue: Drop skip_fdq argument from k3_udma_glue_reset_rx_chn

The user of k3_udma_glue_reset_rx_chn() e.g. ti_am65_cpsw_nuss can
run on multiple platforms having different DMA architectures.
On some platforms there can be one FDQ for all flows in the RX channel
while for others there is a separate FDQ for each flow in the RX channel.

So far we have been relying on the skip_fdq argument of
k3_udma_glue_reset_rx_chn().

Instead of relying on the user to provide this information, infer it
based on DMA architecture during k3_udma_glue_request_rx_chn() and save it
in an internal flag 'single_fdq'. Use that flag at
k3_udma_glue_reset_rx_chn() to deicide if the FDQ needs
to be cleared for every flow or just for flow 0.

Fixes the below issue on ti_am65_cpsw_nuss driver on AM62-SK.

> ip link set eth1 down
> ip link set eth0 down
> ethtool -L eth0 rx 8
> ip link set eth0 up
> modprobe -r ti_am65_cpsw_nuss

[  103.045726] ------------[ cut here ]------------
[  103.050505] k3_knav_desc_pool size 512000 != avail 64000
[  103.050703] WARNING: CPU: 1 PID: 450 at drivers/net/ethernet/ti/k3-cppi-desc-pool.c:33 k3_cppi_desc_pool_destroy+0xa0/0xa8 [k3_cppi_desc_pool]
[  103.068810] Modules linked in: ti_am65_cpsw_nuss(-) k3_cppi_desc_pool snd_soc_hdmi_codec crct10dif_ce snd_soc_simple_card snd_soc_simple_card_utils display_connector rtc_ti_k3 k3_j72xx_bandgap tidss drm_client_lib snd_soc_davinci_mcas
p drm_dma_helper tps6598x phylink snd_soc_ti_udma rti_wdt drm_display_helper snd_soc_tlv320aic3x_i2c typec at24 phy_gmii_sel snd_soc_ti_edma snd_soc_tlv320aic3x sii902x snd_soc_ti_sdma sa2ul omap_mailbox drm_kms_helper authenc cfg80211 r
fkill fuse drm drm_panel_orientation_quirks backlight ip_tables x_tables ipv6 [last unloaded: k3_cppi_desc_pool]
[  103.119950] CPU: 1 UID: 0 PID: 450 Comm: modprobe Not tainted 6.13.0-rc7-00001-g9c5e3435fa66 #1011
[  103.119968] Hardware name: Texas Instruments AM625 SK (DT)
[  103.119974] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  103.119983] pc : k3_cppi_desc_pool_destroy+0xa0/0xa8 [k3_cppi_desc_pool]
[  103.148007] lr : k3_cppi_desc_pool_destroy+0xa0/0xa8 [k3_cppi_desc_pool]
[  103.154709] sp : ffff8000826ebbc0
[  103.158015] x29: ffff8000826ebbc0 x28: ffff0000090b6300 x27: 0000000000000000
[  103.165145] x26: 0000000000000000 x25: 0000000000000000 x24: ffff0000019df6b0
[  103.172271] x23: ffff0000019df6b8 x22: ffff0000019df410 x21: ffff8000826ebc88
[  103.179397] x20: 000000000007d000 x19: ffff00000a3b3000 x18: 0000000000000000
[  103.186522] x17: 0000000000000000 x16: 0000000000000000 x15: 000001e8c35e1cde
[  103.193647] x14: 0000000000000396 x13: 000000000000035c x12: 0000000000000000
[  103.200772] x11: 000000000000003a x10: 00000000000009c0 x9 : ffff8000826eba20
[  103.207897] x8 : ffff0000090b6d20 x7 : ffff00007728c180 x6 : ffff00007728c100
[  103.215022] x5 : 0000000000000001 x4 : ffff000000508a50 x3 : ffff7ffff6146000
[  103.222147] x2 : 0000000000000000 x1 : e300b4173ee6b200 x0 : 0000000000000000
[  103.229274] Call trace:
[  103.231714]  k3_cppi_desc_pool_destroy+0xa0/0xa8 [k3_cppi_desc_pool] (P)
[  103.238408]  am65_cpsw_nuss_free_rx_chns+0x28/0x4c [ti_am65_cpsw_nuss]
[  103.244942]  devm_action_release+0x14/0x20
[  103.249040]  release_nodes+0x3c/0x68
[  103.252610]  devres_release_all+0x8c/0xdc
[  103.256614]  device_unbind_cleanup+0x18/0x60
[  103.260876]  device_release_driver_internal+0xf8/0x178
[  103.266004]  driver_detach+0x50/0x9c
[  103.269571]  bus_remove_driver+0x6c/0xbc
[  103.273485]  driver_unregister+0x30/0x60
[  103.277401]  platform_driver_unregister+0x14/0x20
[  103.282096]  am65_cpsw_nuss_driver_exit+0x18/0xff4 [ti_am65_cpsw_nuss]
[  103.288620]  __arm64_sys_delete_module+0x17c/0x25c
[  103.293404]  invoke_syscall+0x44/0x100
[  103.297149]  el0_svc_common.constprop.0+0xc0/0xe0
[  103.301845]  do_el0_svc+0x1c/0x28
[  103.305155]  el0_svc+0x28/0x98
---truncated---


Remediation: