Description
In the Linux kernel, the following vulnerability has been resolved: slimbus: qcom-ngd-ctrl: Avoid ABBA on tx_lock/ctrl->lock During the SSR/PDR down notification the tx_lock is taken with the intent to provide synchronization with active DMA transfers. But during this period qcom_slim_ngd_down() is invoked, which ends up in slim_report_absent(), which takes the slim_controller lock. In multiple other codepaths these two locks are taken in the opposite order (i.e. slim_controller then tx_lock). The result is a lockdep splat, and a possible deadlock: rprocctl/449 is trying to acquire lock: ffff00009793e620 (&ctrl->lock){+.+.}-{4:4}, at: slim_report_absent (drivers/slimbus/core.c:322) slimbus but task is already holding lock: ffff00009793fb50 (&ctrl->tx_lock){+.+.}-{4:4}, at: qcom_slim_ngd_ssr_pdr_notify (drivers/slimbus/qcom-ngd-ctrl.c:1475) slim_qcom_ngd_ctrl which lock already depends on the new lock. Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ctrl->tx_lock); lock(&ctrl->lock); lock(&ctrl->tx_lock); lock(&ctrl->lock); The assumption is that the comment refers to the desire to not call qcom_slim_ngd_exit_dma() while we have an ongoing DMA TX transaction. But any such transaction is initiated and completed within a single qcom_slim_ngd_xfer_msg(). Prior to calling qcom_slim_ngd_exit_dma() the slim_controller is torn down, all child devices are notified that the slimbus is gone and the child devices are removed. Stop taking the tx_lock in qcom_slim_ngd_ssr_pdr_notify() to avoid the deadlock.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
a899d324863a3d15ce0eea513884e1b73a758c58 to < 3d1561537237c6cc1db76155183d8bbdac2339f0affecteda899d324863a3d15ce0eea513884e1b73a758c58 to < dc4d5c57e012c2c669793deb1515a57bbc6bf5ddaffecteda899d324863a3d15ce0eea513884e1b73a758c58 to < d54a221b0f3cd9e1f03f18104be34e02a8258faeaffecteda899d324863a3d15ce0eea513884e1b73a758c58 to < aad4337a21b9ad3ae8d668fa8678d05e26ecbaa8affecteda899d324863a3d15ce0eea513884e1b73a758c58 to < 9f0d45d509b434c54da10e01f4ef8086e4583401affecteda899d324863a3d15ce0eea513884e1b73a758c58 to < 9708eb50fd7343145b422be852f890212155d845affecteda899d324863a3d15ce0eea513884e1b73a758c58 to < 55f2ea9ff83cc27a85526b14bc9b32f96a08d6ecaffected
Linux Linux
Default version status: affected
5.11affected0 to < 5.11unaffected5.15.210 to ≤ 5.15.*unaffected6.1.176 to ≤ 6.1.*unaffected6.6.143 to ≤ 6.6.*unaffected6.12.94 to ≤ 6.12.*unaffected6.18.36 to ≤ 6.18.*unaffected7.0.13 to ≤ 7.0.*unaffected7.1 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/3d1561537237c6cc1db76155183d8bbdac2339f0 ↗
- https://git.kernel.org/stable/c/dc4d5c57e012c2c669793deb1515a57bbc6bf5dd ↗
- https://git.kernel.org/stable/c/d54a221b0f3cd9e1f03f18104be34e02a8258fae ↗
- https://git.kernel.org/stable/c/aad4337a21b9ad3ae8d668fa8678d05e26ecbaa8 ↗
- https://git.kernel.org/stable/c/9f0d45d509b434c54da10e01f4ef8086e4583401 ↗
- https://git.kernel.org/stable/c/9708eb50fd7343145b422be852f890212155d845 ↗
- https://git.kernel.org/stable/c/55f2ea9ff83cc27a85526b14bc9b32f96a08d6ec ↗