kernel/linux.git/drivers/char/hw_random, branch v7.1.12

hwrng: jh7110 - fix refcount leak in starfive_trng_read()

2026-07-18T14:55:39+00:00

commit 8d13f7a8450206e3f820cdb26e33e91d181071b4 upstream. The starfive_trng_read() function acquires a runtime PM reference via pm_runtime_get_sync() but fails to release it on two error paths. If starfive_trng_wait_idle() or starfive_trng_cmd() returns an error, the function exits without calling pm_runtime_put_sync_autosuspend(), leaving the runtime PM usage counter permanently elevated and preventing the device from entering runtime suspend. Refactor the function to use a unified error path that calls pm_runtime_put_sync_autosuspend() before returning. Cc: stable@vger.kernel.org Fixes: c388f458bc34 ("hwrng: starfive - Add TRNG driver for StarFive SoC") Signed-off-by: Wentao Liang Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

hwrng: virtio: clamp device-reported used.len at copy_data()

2026-07-18T14:55:25+00:00

commit e3046eeada299f917a8ad883af4434bfb86556b1 upstream. random_recv_done() stores the device-reported used.len directly into vi->data_avail. copy_data() then indexes vi->data[] using vi->data_idx (advanced by previous copy_data() calls) and issues a memcpy() without re-validating either value against the posted buffer size sizeof(vi->data) (SMP_CACHE_BYTES bytes, typically 32 or 64). A malicious or buggy virtio-rng backend can set used.len beyond sizeof(vi->data), steering the memcpy() past the end of the inline array into adjacent kmalloc-1k slab bytes. hwrng_fillfn() mixes those bytes into the guest RNG, and guest root can also observe them directly via /dev/hwrng. Concrete impact is inside the guest: - Memory-safety / hardening: any virtio-rng backend that over-reports used.len causes the driver to read past vi->data into unrelated slab contents. hwrng_fillfn() is a kernel thread that runs as soon as the device is probed; no guest userspace interaction is required to first-trigger the OOB. - Cross-boundary leak (confidential-compute threat model): a malicious hypervisor cooperating with a malicious or compromised guest root userspace can use /dev/hwrng as a leak channel for guest-kernel heap data. The host sets a large used.len, guest root reads /dev/hwrng, and the returned bytes contain guest kernel slab contents that were adjacent to vi->data. In practice, confidential-compute guests (SEV-SNP, TDX) usually disable virtio-rng entirely, so this path is narrow, but the fix is still worth carrying because the underlying memory-safety bug contaminates the guest RNG on any host. KASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend has been patched to report used.len = 0x10000: BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0 Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52 Call Trace: __asan_memcpy+0x23/0x60 virtio_read+0x394/0x5d0 hwrng_fillfn+0xb2/0x470 kthread+0x2cc/0x3a0 Allocated by task 1: probe_common+0xa5/0x660 virtio_dev_probe+0x549/0xbc0 The buggy address belongs to the object at ffff88800ae0b800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes to the right of allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20) Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer overflow in USB transport layer"), which hardened usb9pfs_rx_complete() against unchecked device-reported length in the USB 9p transport. With the clamp at point of use and array_index_nospec() in place, the same harness boots cleanly: copy_data() returns zero for the bogus report, the device-supplied bytes after data_idx are discarded, and the driver issues a fresh request. Fixes: f7f510ec1957 ("virtio: An entropy device, as suggested by hpa.") Cc: stable@vger.kernel.org Suggested-by: Michael S. Tsirkin Signed-off-by: Michael Bommarito Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Michael S. Tsirkin Message-ID: <20260531142251.2792061-1-michael.bommarito@gmail.com> Signed-off-by: Greg Kroah-Hartman

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2026-02-13T20:02:18+00:00

Pull virtio updates from Michael Tsirkin: - in-order support in virtio core - multiple address space support in vduse - fixes, cleanups all over the place, notably dma alignment fixes for non-cache-coherent systems * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (59 commits) vduse: avoid adding implicit padding vhost: fix caching attributes of MMIO regions by setting them explicitly vdpa/mlx5: update MAC address handling in mlx5_vdpa_set_attr() vdpa/mlx5: reuse common function for MAC address updates vdpa/mlx5: update mlx_features with driver state check crypto: virtio: Replace package id with numa node id crypto: virtio: Remove duplicated virtqueue_kick in virtio_crypto_skcipher_crypt_req crypto: virtio: Add spinlock protection with virtqueue notification Documentation: Add documentation for VDUSE Address Space IDs vduse: bump version number vduse: add vq group asid support vduse: merge tree search logic of IOTLB_GET_FD and IOTLB_GET_INFO ioctls vduse: take out allocations from vduse_dev_alloc_coherent vduse: remove unused vaddr parameter of vduse_domain_free_coherent vduse: refactor vdpa_dev_add for goto err handling vhost: forbid change vq groups ASID if DRIVER_OK is set vdpa: document set_group_asid thread safety vduse: return internal vq group struct as map token vduse: add vq group support vduse: add v1 API definition ...

Merge tag 'soc-drivers-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

2026-02-11T04:45:30+00:00

Pull SoC driver updates from Arnd Bergmann: "There are are a number of to firmware drivers, in particular the TEE subsystem: - a bus callback for TEE firmware that device drivers can register to - sysfs support for tee firmware information - minor updates to platform specific TEE drivers for AMD, NXP, Qualcomm and the generic optee driver - ARM SCMI firmware refactoring to improve the protocol discover among other fixes and cleanups - ARM FF-A firmware interoperability improvements The reset controller and memory controller subsystems gain support for additional hardware platforms from Mediatek, Renesas, NXP, Canaan and SpacemiT. Most of the other changes are for random drivers/soc code. Among a number of cleanups and newly added hardware support, including: - Mediatek MT8196 DVFS power management and mailbox support - Qualcomm SCM firmware and MDT loader refactoring, as part of the new Glymur platform support. - NXP i.MX9 System Manager firmware support for accessing the syslog - Minor updates for TI, Renesas, Samsung, Apple, Marvell and AMD SoCs" * tag 'soc-drivers-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (171 commits) bus: fsl-mc: fix an error handling in fsl_mc_device_add() reset: spacemit: Add SpacemiT K3 reset driver reset: spacemit: Extract common K1 reset code reset: Create subdirectory for SpacemiT drivers dt-bindings: soc: spacemit: Add K3 reset support and IDs reset: canaan: k230: drop OF dependency and enable by default reset: rzg2l-usbphy-ctrl: Add suspend/resume support reset: rzg2l-usbphy-ctrl: Propagate the return value of regmap_field_update_bits() reset: gpio: check the return value of gpiod_set_value_cansleep() reset: imx8mp-audiomix: Support i.MX8ULP SIM LPAV reset: imx8mp-audiomix: Extend the driver usage reset: imx8mp-audiomix: Switch to using regmap API reset: imx8mp-audiomix: Drop unneeded macros soc: fsl: qe: qe_ports_ic: Consolidate chained IRQ handler install/remove soc: mediatek: mtk-cmdq: Add mminfra_offset adjustment for DRAM addresses soc: mediatek: mtk-cmdq: Extend cmdq_pkt_write API for SoCs without subsys ID soc: mediatek: mtk-cmdq: Add pa_base parsing for hardware without subsys ID support soc: mediatek: mtk-cmdq: Add cmdq_get_mbox_priv() in cmdq_pkt_create() mailbox: mtk-cmdq: Add driver data to support for MT8196 mailbox: mtk-cmdq: Add mminfra_offset configuration for DRAM transaction ...

hwrng: core - use RCU and work_struct to fix race condition

2026-02-06T10:52:22+00:00

Currently, hwrng_fill is not cleared until the hwrng_fillfn() thread exits. Since hwrng_unregister() reads hwrng_fill outside the rng_mutex lock, a concurrent hwrng_unregister() may call kthread_stop() again on the same task. Additionally, if hwrng_unregister() is called immediately after hwrng_register(), the stopped thread may have never been executed. Thus, hwrng_fill remains dirty even after hwrng_unregister() returns. In this case, subsequent calls to hwrng_register() will fail to start new threads, and hwrng_unregister() will call kthread_stop() on the same freed task. In both cases, a use-after-free occurs: refcount_t: addition on 0; use-after-free. WARNING: ... at lib/refcount.c:25 refcount_warn_saturate+0xec/0x1c0 Call Trace: kthread_stop+0x181/0x360 hwrng_unregister+0x288/0x380 virtrng_remove+0xe3/0x200 This patch fixes the race by protecting the global hwrng_fill pointer inside the rng_mutex lock, so that hwrng_fillfn() thread is stopped only once, and calls to kthread_run() and kthread_stop() are serialized with the lock held. To avoid deadlock in hwrng_fillfn() while being stopped with the lock held, we convert current_rng to RCU, so that get_current_rng() can read current_rng without holding the lock. To remove the lock from put_rng(), we also delay the actual cleanup into a work_struct. Since get_current_rng() no longer returns ERR_PTR values, the IS_ERR() checks are removed from its callers. With hwrng_fill protected by the rng_mutex lock, hwrng_fillfn() can no longer clear hwrng_fill itself. Therefore, if hwrng_fillfn() returns directly after current_rng is dropped, kthread_stop() would be called on a freed task_struct later. To fix this, hwrng_fillfn() calls schedule() now to keep the task alive until being stopped. The kthread_stop() call is also moved from hwrng_unregister() to drop_current_rng(), ensuring kthread_stop() is called on all possible paths where current_rng becomes NULL, so that the thread would not wait forever. Fixes: be4000bc4644 ("hwrng: create filler thread") Suggested-by: Herbert Xu Signed-off-by: Lianjie Wang Signed-off-by: Herbert Xu

hwrng: optee - simplify OP-TEE context match

2026-02-06T10:52:22+00:00

Simplify the TEE implementor ID match by returning the boolean expression directly instead of going through an if/else. Signed-off-by: Rouven Czerwinski Signed-off-by: Herbert Xu

hwrng: airoha - set rng quality to 900

2026-01-23T05:48:44+00:00

Airoha uses RAW mode to collect noise from the TRNG. These appear to be unprocessed oscillations from the tero loop. For this reason, they do not have a perfect distribution and entropy. Simple noise compression reduces its size by 9%, so setting the quality to 900 seems reasonable. The same value is used by the downstream driver. Compare the size before and after compression: $ ls -l random_airoha* -rw-r--r-- 1 aleksander aleksander 76546048 Jan 3 23:43 random_airoha -rw-rw-r-- 1 aleksander aleksander 69783562 Jan 5 20:23 random_airoha.zip FIPS test results: $ cat random_airoha | rngtest -c 10000 rngtest 2.6 Copyright (c) 2004 by Henrique de Moraes Holschuh This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. rngtest: starting FIPS tests... rngtest: bits received from input: 200000032 rngtest: FIPS 140-2 successes: 0 rngtest: FIPS 140-2 failures: 10000 rngtest: FIPS 140-2(2001-10-10) Monobit: 9957 rngtest: FIPS 140-2(2001-10-10) Poker: 10000 rngtest: FIPS 140-2(2001-10-10) Runs: 10000 rngtest: FIPS 140-2(2001-10-10) Long run: 4249 rngtest: FIPS 140-2(2001-10-10) Continuous run: 0 rngtest: input channel speed: (min=953.674; avg=27698.935; max=19073.486)Mibits/s rngtest: FIPS tests speed: (min=59.791; avg=298.028; max=328.853)Mibits/s rngtest: Program run time: 647638 microseconds In general, these data look like real noise, but with lower entropy than expected. Fixes: e53ca8efcc5e ("hwrng: airoha - add support for Airoha EN7581 TRNG") Suggested-by: Benjamin Larsson Signed-off-by: Aleksander Jan Bajkowski Signed-off-by: Herbert Xu

virtio-rng: fix DMA alignment for data buffer

2026-01-08T14:54:27+00:00

The data buffer in struct virtrng_info is used for DMA_FROM_DEVICE via virtqueue_add_inbuf() and shares cachelines with the adjacent CPU-written fields (data_avail, data_idx). The device writing to the DMA buffer and the CPU writing to adjacent fields could corrupt each other's data on non-cache-coherent platforms. Add __dma_from_device_group_begin()/end() annotations to place these in distinct cache lines. Message-ID: <157a63b6324d1f1307ddd4faa3b62a8b90a79423.1767601130.git.mst@redhat.com> Signed-off-by: Michael S. Tsirkin