CVE-2025-38478
comedi: Fix initialization of data for instructions that write to subdevice
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comedi: Fix initialization of data for instructions that write to subdevice
In the Linux kernel, the following vulnerability has been resolved: comedi: Fix initialization of data for instructions that write to subdevice Some Comedi subdevice instruction handlers are known to access instruction data elements beyond the first `insn->n` elements in some cases. The `do_insn_ioctl()` and `do_insnlist_ioctl()` functions allocate at least `MIN_SAMPLES` (16) data elements to deal with this, but they do not initialize all of that. For Comedi instruction codes that write to the subdevice, the first `insn->n` data elements are copied from user-space, but the remaining elements are left uninitialized. That could be a problem if the subdevice instruction handler reads the uninitialized data. Ensure that the first `MIN_SAMPLES` elements are initialized before calling these instruction handlers, filling the uncopied elements with 0. For `do_insnlist_ioctl()`, the same data buffer elements are used for handling a list of instructions, so ensure the first `MIN_SAMPLES` elements are initialized for each instruction that writes to the subdevice.
Reserved 2025-04-16 | Published 2025-07-28 | Updated 2025-07-28 | Assigner Linuxgit.kernel.org/...c/d3436638738ace8f101af7bdee2eae1bc38e9b29
git.kernel.org/...c/673ee92bd2d31055bca98a1d96b653f5284289c4
git.kernel.org/...c/c42116dc70af6664526f7aa82cf937824ab42649
git.kernel.org/...c/fe8713fb4e4e82a4f91910d9a41bf0613e69a0b9
git.kernel.org/...c/46d8c744136ce2454aa4c35c138cc06817f92b8e
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