qemu/qemu.git/backends/rng.c, branch master

backends/rng: cap request size to avoid oversized allocation

2026-07-27T19:14:13+00:00

rng_backend_request_entropy() uses the requested size to allocate a buffer with g_malloc(). With virtio-rng, this size comes from guest-supplied descriptor lengths. A malicious guest can set a very large descriptor length, causing QEMU to attempt a multi-gigabyte allocation and abort. Cap the allocation to 64 KiB. The virtio-rng queue size is hardcoded to 8 entries, the EGD backend protocol limits requests to 255 bytes, the Linux kernel hwrng framework requests at most SMP_CACHE_BYTES per call (64 bytes on x86_64), and the Windows viorng driver uses a 4 KiB buffer. The worst legitimate case is 8 x 4 KiB = 32 KiB, so 64 KiB is well above any legitimate use. Fixes: 14417039653d ("virtio-rng: use virtqueue_get_avail_bytes, fix migration") Cc: qemu-stable@nongnu.org Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3983 Reported-by: dong ling Signed-off-by: Laurent Vivier Reviewed-by: Thomas Huth Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Message-ID: <20260715141300.2295392-1-lvivier@redhat.com>

hw/virtio-rng: Fix host use-after-free (CVE-2026-50624)

2026-07-27T19:14:13+00:00

Fix a heap-use-after-free in the virtio-rng frontend when a delayed rng-random backend completion arrives after the virtio-rng device has been hot-unplugged. Fixes: CVE-2026-50624 Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3917 Reported-by: Jia Jia Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Laurent Vivier Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Message-ID: <20260724094931.3005968-1-lvivier@redhat.com>

qom: Make InterfaceInfo[] uses const

2025-04-25T15:00:41+00:00

Mechanical change using: $ sed -i -E 's/$InterfaceInfo.?\[/\(const InterfaceInfo\[/g' \ $(git grep -lE '\(InterfaceInfo.?\[\]$') Reviewed-by: Richard Henderson Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20250424194905.82506-7-philmd@linaro.org>

qom: Have class_init() take a const data argument

2025-04-25T15:00:41+00:00

Mechanical change using gsed, then style manually adapted to pass checkpatch.pl script. Suggested-by: Richard Henderson Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Message-Id: <20250424194905.82506-4-philmd@linaro.org>

include: Rename sysemu/ -> system/

2024-12-20T16:44:56+00:00

Headers in include/sysemu/ are not only related to system *emulation*, they are also used by virtualization. Rename as system/ which is clearer. Files renamed manually then mechanical change using sed tool. Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson Tested-by: Lei Yang Message-Id: <20241203172445.28576-1-philmd@linaro.org>

error: Drop superfluous #include "qapi/qmp/qerror.h"

2023-02-23T12:56:14+00:00

Signed-off-by: Markus Armbruster Message-Id: <20230207075115.1525-2-armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Juan Quintela Reviewed-by: Konstantin Kostiuk

rng: make opened property read-only

2022-05-14T10:33:44+00:00

The ``opened=on`` option in the command line or QMP ``object-add`` either had no effect (if ``opened`` was the last option) or caused errors. The property is therefore useless and was deprecated in 6.0; make it read-only now. Signed-off-by: Paolo Bonzini

rng: Register "opened" as class property

2020-10-13T19:56:30+00:00

Class properties make QOM introspection simpler and easier, as they don't require an object to be instantiated. Signed-off-by: Eduardo Habkost Reviewed-by: Daniel P. Berrangé Message-Id: <20200921221045.699690-8-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost

qom: Put name parameter before value / visitor parameter

2020-07-10T13:18:08+00:00

The object_property_set_FOO() setters take property name and value in an unusual order: void object_property_set_FOO(Object *obj, FOO_TYPE value, const char *name, Error **errp) Having to pass value before name feels grating. Swap them. Same for object_property_set(), object_property_get(), and object_property_parse(). Convert callers with this Coccinelle script: @@ identifier fun = { object_property_get, object_property_parse, object_property_set_str, object_property_set_link, object_property_set_bool, object_property_set_int, object_property_set_uint, object_property_set, object_property_set_qobject }; expression obj, v, name, errp; @@ - fun(obj, v, name, errp) + fun(obj, name, v, errp) Chokes on hw/arm/musicpal.c's lcd_refresh() with the unhelpful error message "no position information". Convert that one manually. Fails to convert hw/arm/armsse.c, because Coccinelle gets confused by ARMSSE being used both as typedef and function-like macro there. Convert manually. Fails to convert hw/rx/rx-gdbsim.c, because Coccinelle gets confused by RXCPU being used both as typedef and function-like macro there. Convert manually. The other files using RXCPU that way don't need conversion. Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Message-Id: <20200707160613.848843-27-armbru@redhat.com> [Straightforwad conflict with commit 2336172d9b "audio: set default value for pcspk.iobase property" resolved]

qom: Drop parameter @errp of object_property_add() & friends

2020-05-15T05:07:58+00:00

The only way object_property_add() can fail is when a property with the same name already exists. Since our property names are all hardcoded, failure is a programming error, and the appropriate way to handle it is passing &error_abort. Same for its variants, except for object_property_add_child(), which additionally fails when the child already has a parent. Parentage is also under program control, so this is a programming error, too. We have a bit over 500 callers. Almost half of them pass &error_abort, slightly fewer ignore errors, one test case handles errors, and the remaining few callers pass them to their own callers. The previous few commits demonstrated once again that ignoring programming errors is a bad idea. Of the few ones that pass on errors, several violate the Error API. The Error ** argument must be NULL, &error_abort, &error_fatal, or a pointer to a variable containing NULL. Passing an argument of the latter kind twice without clearing it in between is wrong: if the first call sets an error, it no longer points to NULL for the second call. ich9_pm_add_properties(), sparc32_ledma_realize(), sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize() are wrong that way. When the one appropriate choice of argument is &error_abort, letting users pick the argument is a bad idea. Drop parameter @errp and assert the preconditions instead. There's one exception to "duplicate property name is a programming error": the way object_property_add() implements the magic (and undocumented) "automatic arrayification". Don't drop @errp there. Instead, rename object_property_add() to object_property_try_add(), and add the obvious wrapper object_property_add(). Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Reviewed-by: Paolo Bonzini Message-Id: <20200505152926.18877-15-armbru@redhat.com> [Two semantic rebase conflicts resolved]