TLDRVuln - Cybersecurity Vulnerabilities Made Simple

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

net: atlantic: Fix DMA mapping for PTP hwts ring

Function aq_ring_hwts_rx_alloc() maps extra AQ_CFG_RXDS_DEF bytes

for PTP HWTS ring but then generic aq_ring_free() does not take this

into account.

Create and use a specific function to free HWTS ring to fix this

issue.

Trace:

[ 215.351607] ------------[ cut here ]------------

[ 215.351612] DMA-API: atlantic 0000:4b:00.0: device driver frees DMA memory with different size [device address=0x00000000fbdd0000] [map size=34816 bytes] [unmap size=32768 bytes]

[ 215.351635] WARNING: CPU: 33 PID: 10759 at kernel/dma/debug.c:988 check_unmap+0xa6f/0x2360

...

[ 215.581176] Call Trace:

[ 215.583632] <TASK>

[ 215.585745] ? show_trace_log_lvl+0x1c4/0x2df

[ 215.590114] ? show_trace_log_lvl+0x1c4/0x2df

[ 215.594497] ? debug_dma_free_coherent+0x196/0x210

[ 215.599305] ? check_unmap+0xa6f/0x2360

[ 215.603147] ? __warn+0xca/0x1d0

[ 215.606391] ? check_unmap+0xa6f/0x2360

[ 215.610237] ? report_bug+0x1ef/0x370

[ 215.613921] ? handle_bug+0x3c/0x70

[ 215.617423] ? exc_invalid_op+0x14/0x50

[ 215.621269] ? asm_exc_invalid_op+0x16/0x20

[ 215.625480] ? check_unmap+0xa6f/0x2360

[ 215.629331] ? mark_lock.part.0+0xca/0xa40

[ 215.633445] debug_dma_free_coherent+0x196/0x210

[ 215.638079] ? __pfx_debug_dma_free_coherent+0x10/0x10

[ 215.643242] ? slab_free_freelist_hook+0x11d/0x1d0

[ 215.648060] dma_free_attrs+0x6d/0x130

[ 215.651834] aq_ring_free+0x193/0x290 [atlantic]

[ 215.656487] aq_ptp_ring_free+0x67/0x110 [atlantic]

...

[ 216.127540] ---[ end trace 6467e5964dd2640b ]---

[ 216.132160] DMA-API: Mapped at:

[ 216.132162] debug_dma_alloc_coherent+0x66/0x2f0

[ 216.132165] dma_alloc_attrs+0xf5/0x1b0

[ 216.132168] aq_ring_hwts_rx_alloc+0x150/0x1f0 [atlantic]

[ 216.132193] aq_ptp_ring_alloc+0x1bb/0x540 [atlantic]

[ 216.132213] aq_nic_init+0x4a1/0x760 [atlantic]