diff options
| author | Yishai Hadas <yishaih@nvidia.com> | 2026-05-25 17:21:36 +0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2026-06-03 14:55:48 -0300 |
| commit | 323c98a4ff06aa28114f2bf658fb43eb3b536bbc (patch) | |
| tree | 1f47a255e20c6952cf71b1163108051ed36be13f | |
| parent | 15fe76e23615f502d051ef0768f86babaf08746c (diff) | |
RDMA/core: Validate cpu_id against nr_cpu_ids in DMAH alloc
The cpu_id attribute supplied by user space through
UVERBS_ATTR_ALLOC_DMAH_CPU_ID is passed directly to cpumask_test_cpu()
without first verifying that the value is within the valid CPU range.
Passing such untrusted data to cpumask_test_cpu() may lead to an
out-of-bounds read of the underlying cpumask bitmap: the helper expands
to a test_bit() that indexes the bitmap by cpu_id / BITS_PER_LONG with
no bound check.
In addition, on kernels built with CONFIG_DEBUG_PER_CPU_MAPS it trips
the WARN_ON_ONCE() in cpumask_check(); combined with panic_on_warn this
turns a bad user input into a machine reboot.
Reject any cpu_id that is not smaller than nr_cpu_ids with -EINVAL
before it is used.
Reported by Smatch.
Fixes: d83edab562a4 ("RDMA/core: Introduce a DMAH object and its alloc/free APIs")
Link: https://patch.msgid.link/r/20260525142136.28165-1-yishaih@nvidia.com
Cc: stable@vger.kernel.org
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/ag68qoAW3P04J7pT@stanley.mountain/
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
| -rw-r--r-- | drivers/infiniband/core/uverbs_std_types_dmah.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/infiniband/core/uverbs_std_types_dmah.c b/drivers/infiniband/core/uverbs_std_types_dmah.c index 453ce656c6f2..97101e093826 100644 --- a/drivers/infiniband/core/uverbs_std_types_dmah.c +++ b/drivers/infiniband/core/uverbs_std_types_dmah.c @@ -47,6 +47,11 @@ static int UVERBS_HANDLER(UVERBS_METHOD_DMAH_ALLOC)( if (ret) goto err; + if (dmah->cpu_id >= nr_cpu_ids) { + ret = -EINVAL; + goto err; + } + if (!cpumask_test_cpu(dmah->cpu_id, current->cpus_ptr)) { ret = -EPERM; goto err; |