Description

In the Linux kernel, the following vulnerability has been resolved: soundwire: Revert "soundwire: qcom: Add set_channel_map api support" This reverts commit 7796c97df6b1b2206681a07f3c80f6023a6593d5. This patch broke Dragonboard 845c (sdm845). I see: Unexpected kernel BRK exception at EL1 Internal error: BRK handler: 00000000f20003e8 [#1] SMP pc : qcom_swrm_set_channel_map+0x7c/0x80 [soundwire_qcom] lr : snd_soc_dai_set_channel_map+0x34/0x78 Call trace: qcom_swrm_set_channel_map+0x7c/0x80 [soundwire_qcom] (P) sdm845_dai_init+0x18c/0x2e0 [snd_soc_sdm845] snd_soc_link_init+0x28/0x6c snd_soc_bind_card+0x5f4/0xb0c snd_soc_register_card+0x148/0x1a4 devm_snd_soc_register_card+0x50/0xb0 sdm845_snd_platform_probe+0x124/0x148 [snd_soc_sdm845] platform_probe+0x6c/0xd0 really_probe+0xc0/0x2a4 __driver_probe_device+0x7c/0x130 driver_probe_device+0x40/0x118 __device_attach_driver+0xc4/0x108 bus_for_each_drv+0x8c/0xf0 __device_attach+0xa4/0x198 device_initial_probe+0x18/0x28 bus_probe_device+0xb8/0xbc deferred_probe_work_func+0xac/0xfc process_one_work+0x244/0x658 worker_thread+0x1b4/0x360 kthread+0x148/0x228 ret_from_fork+0x10/0x20 Kernel panic - not syncing: BRK handler: Fatal exception Dan has also reported following issues with the original patch https://lore.kernel.org/all/33fe8fe7-719a-405a-9ed2-d9f816ce1d57@sabinyo.mountain/ Bug #1: The zeroeth element of ctrl->pconfig[] is supposed to be unused. We start counting at 1. However this code sets ctrl->pconfig[0].ch_mask = 128. Bug #2: There are SLIM_MAX_TX_PORTS (16) elements in tx_ch[] array but only QCOM_SDW_MAX_PORTS + 1 (15) in the ctrl->pconfig[] array so it corrupts memory like Yongqin Liu pointed out. Bug 3: Like Jie Gan pointed out, it erases all the tx information with the rx information.

Affected Products 7

References 2

• git.kernel.org https://git.kernel.org/stable/c/207cea8b72fcbdf4e6db178e54186ed4f1514b3c
  Patch
• git.kernel.org https://git.kernel.org/stable/c/834bce6a715ae9a9c4dce7892454a19adf22b013
  Patch

Remediation

• git.kernel.org https://git.kernel.org/stable/c/207cea8b72fcbdf4e6db178e54186ed4f1514b3c
  Patch
• git.kernel.org https://git.kernel.org/stable/c/834bce6a715ae9a9c4dce7892454a19adf22b013
  Patch