On 1/23/25 9:39 AM, Murad Masimov wrote:
Syzkaller has reported a warning in to_nfit_bus_uuid(): "only secondary bus families can be translated". This warning is emited if the argument is equal to NVDIMM_BUS_FAMILY_NFIT == 0. Function acpi_nfit_ctl() first verifies that a user-provided value call_pkg->nd_family of type u64 is not equal to 0. Then the value is converted to int, and only after that is compared to NVDIMM_BUS_FAMILY_MAX. This can lead to passing an invalid argument to acpi_nfit_ctl(), if call_pkg->nd_family is non-zero, while the lower 32 bits are zero.
All checks of the input value should be applied to the original variable call_pkg->nd_family.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 6450ddbd5d8e ("ACPI: NFIT: Define runtime firmware activation commands") Cc: stable@vger.kernel.org Reported-by: syzbot+c80d8dc0d9fa81a3cd8c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c80d8dc0d9fa81a3cd8c Signed-off-by: Murad Masimov m.masimov@mt-integration.ru
While the change logically makes sense, the likelihood of nd_family > int_size is not ever likely. Given that NVDIMM_BUS_FAMILY_MAX is defined as 1, I don't think we care about values greater than that regardless of what is set in the upper 32bit of the u64. I'm leaning towards the fix is unnecessary.
drivers/acpi/nfit/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index a5d47819b3a4..ae035b93da08 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -485,7 +485,7 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, cmd_mask = nd_desc->cmd_mask; if (cmd == ND_CMD_CALL && call_pkg->nd_family) { family = call_pkg->nd_family;
if (family > NVDIMM_BUS_FAMILY_MAX ||
if (call_pkg->nd_family > NVDIMM_BUS_FAMILY_MAX || !test_bit(family, &nd_desc->bus_family_mask)) return -EINVAL; family = array_index_nospec(family,-- 2.39.2