RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send

Browse source

[ Upstream commit 1956f0a74c ]

ib_uverbs_post_send() uses cmd.wqe_size from userspace without any
validation before passing it to kmalloc() and using the allocated
buffer as struct ib_uverbs_send_wr.

If a user provides a small wqe_size value (e.g., 1), kmalloc() will
succeed, but subsequent accesses to user_wr->opcode, user_wr->num_sge,
and other fields will read beyond the allocated buffer, resulting in
an out-of-bounds read from kernel heap memory. This could potentially
leak sensitive kernel information to userspace.

Additionally, providing an excessively large wqe_size can trigger a
WARNING in the memory allocation path, as reported by syzkaller.

This is inconsistent with ib_uverbs_unmarshall_recv() which properly
validates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before
proceeding.

Add the same validation for ib_uverbs_post_send() to ensure wqe_size
is at least sizeof(struct ib_uverbs_send_wr).

Fixes: c3bea3d2dc ("RDMA/uverbs: Use the iterator for ib_uverbs_unmarshall_recv()")
Signed-off-by: Yi Liu <liuy22@mails.tsinghua.edu.cn>
Link: https://patch.msgid.link/20260122142900.2356276-2-liuy22@mails.tsinghua.edu.cn
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

Yi Liu 2026-01-22 22:29:00 +08:00 • committed by Greg Kroah-Hartman

parent 409c2c5508

commit bf4454da8b

1 changed files with 4 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

5

drivers/infiniband/core/uverbs_cmd.c

View file