[PATCH net] net: stmmac: fix dma queue left shift overflow issue

[Florian Fainelli]

On 7/15/22 00:47, Junxiao Chang wrote:
> When queue number is > 4, left shift overflows due to 32 bits
> integer variable. Mask calculation is wrong for MTL_RXQ_DMA_MAP1.
> 
> If CONFIG_UBSAN is enabled, kernel dumps below warning:
> [   10.363842] ==================================================================
> [   10.363882] UBSAN: shift-out-of-bounds in /build/linux-intel-iotg-5.15-8e6Tf4/
> linux-intel-iotg-5.15-5.15.0/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c:224:12
> [   10.363929] shift exponent 40 is too large for 32-bit type 'unsigned int'
> [   10.363953] CPU: 1 PID: 599 Comm: NetworkManager Not tainted 5.15.0-1003-intel-iotg
> [   10.363956] Hardware name: ADLINK Technology Inc. LEC-EL/LEC-EL, BIOS 0.15.11 12/22/2021
> [   10.363958] Call Trace:
> [   10.363960]  <TASK>
> [   10.363963]  dump_stack_lvl+0x4a/0x5f
> [   10.363971]  dump_stack+0x10/0x12
> [   10.363974]  ubsan_epilogue+0x9/0x45
> [   10.363976]  __ubsan_handle_shift_out_of_bounds.cold+0x61/0x10e
> [   10.363979]  ? wake_up_klogd+0x4a/0x50
> [   10.363983]  ? vprintk_emit+0x8f/0x240
> [   10.363986]  dwmac4_map_mtl_dma.cold+0x42/0x91 [stmmac]
> [   10.364001]  stmmac_mtl_configuration+0x1ce/0x7a0 [stmmac]
> [   10.364009]  ? dwmac410_dma_init_channel+0x70/0x70 [stmmac]
> [   10.364020]  stmmac_hw_setup.cold+0xf/0xb14 [stmmac]
> [   10.364030]  ? page_pool_alloc_pages+0x4d/0x70
> [   10.364034]  ? stmmac_clear_tx_descriptors+0x6e/0xe0 [stmmac]
> [   10.364042]  stmmac_open+0x39e/0x920 [stmmac]
> [   10.364050]  __dev_open+0xf0/0x1a0
> [   10.364054]  __dev_change_flags+0x188/0x1f0
> [   10.364057]  dev_change_flags+0x26/0x60
> [   10.364059]  do_setlink+0x908/0xc40
> [   10.364062]  ? do_setlink+0xb10/0xc40
> [   10.364064]  ? __nla_validate_parse+0x4c/0x1a0
> [   10.364068]  __rtnl_newlink+0x597/0xa10
> [   10.364072]  ? __nla_reserve+0x41/0x50
> [   10.364074]  ? __kmalloc_node_track_caller+0x1d0/0x4d0
> [   10.364079]  ? pskb_expand_head+0x75/0x310
> [   10.364082]  ? nla_reserve_64bit+0x21/0x40
> [   10.364086]  ? skb_free_head+0x65/0x80
> [   10.364089]  ? security_sock_rcv_skb+0x2c/0x50
> [   10.364094]  ? __cond_resched+0x19/0x30
> [   10.364097]  ? kmem_cache_alloc_trace+0x15a/0x420
> [   10.364100]  rtnl_newlink+0x49/0x70
> 
> This change fixes MTL_RXQ_DMA_MAP1 mask issue and channel/queue
> mapping warning.
> 
> Fixes: d43042f4da3e ("net: stmmac: mapping mtl rx to dma channel")
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216195
> Reported-by: Cedric Wassenaar <cedric at bytespeed.nl>
> Signed-off-by: Junxiao Chang <junxiao.chang at intel.com>

Reviewed-by: Florian Fainelli <f.fainelli at gmail.com>

Thank you!
-- 
Florian