Description
In the Linux kernel, the following vulnerability has been resolved: dmaengine: qcom: bam_dma: Fix DT error handling for num-channels/ees When we don't have a clock specified in the device tree, we have no way to ensure the BAM is on. This is often the case for remotely-controlled or remotely-powered BAM instances. In this case, we need to read num-channels from the DT to have all the necessary information to complete probing. However, at the moment invalid device trees without clock and without num-channels still continue probing, because the error handling is missing return statements. The driver will then later try to read the number of channels from the registers. This is unsafe, because it relies on boot firmware and lucky timing to succeed. Unfortunately, the lack of proper error handling here has been abused for several Qualcomm SoCs upstream, causing early boot crashes in several situations [1, 2]. Avoid these early crashes by erroring out when any of the required DT properties are missing. Note that this will break some of the existing DTs upstream (mainly BAM instances related to the crypto engine). However, clearly these DTs have never been tested properly, since the error in the kernel log was just ignored. It's safer to disable the crypto engine for these broken DTBs. [1]: https://lore.kernel.org/r/CY01EKQVWE36.B9X5TDXAREPF@fairphone.com/ [2]: https://lore.kernel.org/r/20230626145959.646747-1-krzysztof.kozlowski@linaro.org/
Product status
48d163b1aa6e7f650c0b7a4f9c61c387a6def868 before 555bd16351a35c79efb029a196975a5a27f7fbc4
48d163b1aa6e7f650c0b7a4f9c61c387a6def868 before ebf6c7c908e5999531c3517289598f187776124f
48d163b1aa6e7f650c0b7a4f9c61c387a6def868 before 1fc14731f0be4885e60702b9596d14d9a79cf053
48d163b1aa6e7f650c0b7a4f9c61c387a6def868 before 0ff9df758af7022d749718fb6b8385cc5693acf3
48d163b1aa6e7f650c0b7a4f9c61c387a6def868 before 5068b5254812433e841a40886e695633148d362d
cecf8a69042b3a54cb843223756c10ee8a8665e3
909474cd384cb206f33461fbd18089cf170533f8
5e0986f7caf17d7b1acd2092975360bf8e88a57d
4.17
Any version before 4.17
6.1.153
6.6.107
6.12.48
6.16.8
6.17
References
git.kernel.org/...c/555bd16351a35c79efb029a196975a5a27f7fbc4
git.kernel.org/...c/ebf6c7c908e5999531c3517289598f187776124f
git.kernel.org/...c/1fc14731f0be4885e60702b9596d14d9a79cf053
git.kernel.org/...c/0ff9df758af7022d749718fb6b8385cc5693acf3
git.kernel.org/...c/5068b5254812433e841a40886e695633148d362d
