CVE-2025-39686 In the Linux kernel, the following vulnerability has been resolved: comedi: Make insn_rw_emulate_bits() do insn->n…
Description
In the Linux kernel, the following vulnerability has been resolved: comedi: Make insn_rw_emulate_bits() do insn->n samples The `insn_rw_emulate_bits()` function is used as a default handler for `INSN_READ` instructions for subdevices that have a handler for `INSN_BITS` but not for `INSN_READ`. Similarly, it is used as a default handler for `INSN_WRITE` instructions for subdevices that have a handler for `INSN_BITS` but not for `INSN_WRITE`. It works by emulating the `INSN_READ` or `INSN_WRITE` instruction handling with a constructed `INSN_BITS` instruction. However, `INSN_READ` and `INSN_WRITE` instructions are supposed to be able read or write multiple samples, indicated by the `insn->n` value, but `insn_rw_emulate_bits()` currently only handles a single sample. For `INSN_READ`, the comedi core will copy `insn->n` samples back to user-space. (That triggered KASAN kernel-infoleak errors when `insn->n` was greater than 1, but that is being fixed more generally elsewhere in the comedi core.) Make `insn_rw_emulate_bits()` either handle `insn->n` samples, or return an error, to conform to the general expectation for `INSN_READ` and `INSN_WRITE` handlers.
Produits et versions touchés
| Produit | Versions touchées | Corrigé en |
|---|---|---|
| Linux 6.17 | premières → < 6.17 | 6.17 |
| Linux 6.16 | premières → < 6.16.4 | 6.16.4 |
| Linux 6.12 | premières → < 6.12.44 | 6.12.44 |
| Linux 6.6 | premières → < 6.6.103 | 6.6.103 |
| Linux 6.1 | premières → < 6.1.149 | 6.1.149 |
| Linux 5.15 | premières → < 5.15.190 | 5.15.190 |
| Linux | 2.6.29 | Pas de correctif indiqué |
| SIMATIC CN 4100 5.0 | premières → < 5.0 | 5.0 |