CVSS 7.8 · High EPSS 0,13%
Kerentanan Use After Free pada linux kernel. Skor CVSS 3.1 7.8 (High) menurut CNA.
In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: fix use-after-free of fastrpc_user in workqueue context There is a race between fastrpc_device_release() and the workqueue that processes DSP responses. When the user closes the file descriptor, fastrpc_device_release() frees the fastrpc_user structure. Concurrently, an in-flight DSP invocation can complete and fastrpc_rpmsg_callback() schedules context cleanup via schedule_work(&ctx->put_work). If the workqueue runs fastrpc_context_free() in parallel with or after fastrpc_device_release() has freed the user structure, it dereferences the freed fastrpc_user. Depending on the state of the context at the time of the race, any one of the following accesses can be hit: 1. fastrpc_buf_free() calls fastrpc_ipa_to_dma_addr(buf->fl->cctx, ...) to strip the SID bits from the stored IOVA before passing the physical address to dma_free_coherent(). 2. fastrpc_free_map() reads map->fl->cctx->vmperms[0].vmid to reconstruct the source permission bitmask needed for the qcom_scm_assign_mem() call that returns memory from the DSP VM back to HLOS. 3. fastrpc_free_map() acquires map->fl->lock to safely remove the map node from the fl->maps list. The resulting use-after-free manifests as: pc : fastrpc_buf_free+0x38/0x80 [fastrpc] lr : fastrpc_context_free+0xa8/0x1b0 [fastrpc] fastrpc_context_free+0xa8/0x1b0 [fastrpc] fastrpc_context_put_wq+0x78/0xa0 [fastrpc] process_one_work+0x180/0x450 worker_thread+0x26c/0x388 Add kref-based reference counting to fastrpc_user. Have each invoke context take a reference on the user at allocation time and release it when the context is freed. Release the initial reference in fastrpc_device_release() at file close. Move the teardown of the user structure — freeing pending contexts, maps, mmaps, and the channel context reference — into the kref release callback fastrpc_user_free(), so that it runs only when the last reference is dropped, regardless of whether that happens at device close or after the final in-flight context completes.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| linux | linux kernel | Versi 5.1 hingga sebelum 5.10.259 |
| linux | linux kernel | Versi 5.11 hingga sebelum 5.15.210 |
| linux | linux kernel | Versi 5.16 hingga sebelum 6.1.176 |
| linux | linux kernel | Versi 6.2 hingga sebelum 6.6.143 |
| linux | linux kernel | Versi 6.7 hingga sebelum 6.12.94 |
| linux | linux kernel | Versi 6.13 hingga sebelum 6.18.36 |
| linux | linux kernel | Versi 6.19 hingga sebelum 7.0.13 |
| linux | linux kernel | Versi 7.1 rc1 |
| linux | linux kernel | Versi 7.1 rc2 |
| linux | linux kernel | Versi 7.1 rc3 |
| linux | linux kernel | Versi 7.1 rc4 |
| linux | linux kernel | Versi 7.1 rc5 |
| linux | linux kernel | Versi 7.1 rc6 |
| linux | linux kernel | Versi 7.1 rc7 |