kernel/linux.git/drivers/char/hw_random, branch v6.6.150

hwrng: jh7110 - fix refcount leak in starfive_trng_read()

2026-07-24T14:02:52+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()

2026-07-24T14:02:43+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

hwrng: ks-sa - fix division by zero in ks_sa_rng_init

2025-10-15T09:58:05+00:00

[ Upstream commit 612b1dfeb414dfa780a6316014ceddf9a74ff5c0 ] Fix division by zero in ks_sa_rng_init caused by missing clock pointer initialization. The clk_get_rate() call is performed on an uninitialized clk pointer, resulting in division by zero when calculating delay values. Add clock initialization code before using the clock. Fixes: 6d01d8511dce ("hwrng: ks-sa - Add minimum sleep time before ready-polling") Signed-off-by: Nishanth Menon drivers/char/hw_random/ks-sa-rng.c | 7 +++++++ 1 file changed, 7 insertions(+) Reviewed-by: Alexander Sverdlin Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

hwrng: nomadik - add ARM_AMBA dependency

2025-10-15T09:57:56+00:00

[ Upstream commit efaa2d815a0e4d1c06750e587100f6f7f4ee5497 ] Compile-testing this driver is only possible when the AMBA bus driver is available in the kernel: x86_64-linux-ld: drivers/char/hw_random/nomadik-rng.o: in function `nmk_rng_remove': nomadik-rng.c:(.text+0x67): undefined reference to `amba_release_regions' x86_64-linux-ld: drivers/char/hw_random/nomadik-rng.o: in function `nmk_rng_probe': nomadik-rng.c:(.text+0xee): undefined reference to `amba_request_regions' x86_64-linux-ld: nomadik-rng.c:(.text+0x18d): undefined reference to `amba_release_regions' The was previously implied by the 'depends on ARCH_NOMADIK', but needs to be specified for the COMPILE_TEST case. Fixes: d5e93b3374e4 ("hwrng: Kconfig - Add helper dependency on COMPILE_TEST") Signed-off-by: Arnd Bergmann Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

hwrng: mtk - handle devm_pm_runtime_enable errors

2025-08-15T10:08:55+00:00

[ Upstream commit 522a242a18adc5c63a24836715dbeec4dc3faee1 ] Although unlikely, devm_pm_runtime_enable() call might fail, so handle the return value. Fixes: 78cb66caa6ab ("hwrng: mtk - Use devm_pm_runtime_enable") Signed-off-by: Ovidiu Panait Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

hwrng: cctrng - Add missing clk_disable_unprepare in cctrng_resume

2024-10-04T14:29:55+00:00

commit 4b7acc85de14ee8a2236f54445dc635d47eceac0 upstream. Add the missing clk_disable_unprepare() before return in cctrng_resume(). Fixes: a583ed310bb6 ("hwrng: cctrng - introduce Arm CryptoCell driver") Cc: Signed-off-by: Gaosheng Cui Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

hwrng: bcm2835 - Add missing clk_disable_unprepare in bcm2835_rng_init

2024-10-04T14:29:55+00:00

commit d57e2f7cffd57fe2800332dec768ec1b67a4159f upstream. Add the missing clk_disable_unprepare() before return in bcm2835_rng_init(). Fixes: e5f9f41d5e62 ("hwrng: bcm2835 - add reset support") Cc: Signed-off-by: Gaosheng Cui Reviewed-by: Florian Fainelli Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

hwrng: mtk - Use devm_pm_runtime_enable

2024-10-04T14:29:54+00:00

commit 78cb66caa6ab5385ac2090f1aae5f3c19e08f522 upstream. Replace pm_runtime_enable with the devres-enabled version which can trigger pm_runtime_disable. Otherwise, the below appears during reload driver. mtk_rng 1020f000.rng: Unbalanced pm_runtime_enable! Fixes: 81d2b34508c6 ("hwrng: mtk - add runtime PM support") Cc: Suggested-by: Chen-Yu Tsai Signed-off-by: Guoqing Jiang Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

hwrng: amd - Convert PCIBIOS_* return codes to errnos

2024-08-03T06:54:21+00:00

commit 14cba6ace79627a57fb9058582b03f0ed3832390 upstream. amd_rng_mod_init() uses pci_read_config_dword() that returns PCIBIOS_* codes. The return code is then returned as is but amd_rng_mod_init() is a module_init() function that should return normal errnos. Convert PCIBIOS_* returns code using pcibios_err_to_errno() into normal errno before returning it. Fixes: 96d63c0297cc ("[PATCH] Add AMD HW RNG driver") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

hwrng: core - Fix wrong quality calculation at hw rng registration

2024-08-03T06:53:59+00:00

[ Upstream commit 95c0f5c3b8bb7acdc5c4f04bc6a7d3f40d319e9e ] When there are rng sources registering at the hwrng core via hwrng_register() a struct hwrng is delivered. There is a quality field in there which is used to decide which of the registered hw rng sources will be used by the hwrng core. With commit 16bdbae39428 ("hwrng: core - treat default_quality as a maximum and default to 1024") there came in a new default of 1024 in case this field is empty and all the known hw rng sources at that time had been reworked to not fill this field and thus use the default of 1024. The code choosing the 'better' hw rng source during registration of a new hw rng source has never been adapted to this and thus used 0 if the hw rng implementation does not fill the quality field. So when two rng sources register, one with 0 (meaning 1024) and the other one with 999, the 999 hw rng will be chosen. As the later invoked function hwrng_init() anyway adjusts the quality field of the hw rng source, this adjustment is now done during registration of this new hw rng source. Tested on s390 with two hardware rng sources: crypto cards and trng true random generator device driver. Fixes: 16bdbae39428 ("hwrng: core - treat default_quality as a maximum and default to 1024") Reported-by: Christian Rund Suggested-by: Herbert Xu Signed-off-by: Harald Freudenberger Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin