Bug 2536408 (CVE-2026-90435) - CVE-2026-90435 kernel: RDMA/mlx5: Fix integer overflow of user QP buffer size
Summary: CVE-2026-90435 kernel: RDMA/mlx5: Fix integer overflow of user QP buffer size
Keywords:
Status: NEW
Alias: CVE-2026-90435
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-17 17:44 UTC by OSIDB Bzimport
Modified: 2026-10-20 11:10 UTC (History)
17 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-09-17 17:44:54 UTC
In the Linux kernel, the following vulnerability has been resolved:

RDMA/mlx5: Fix integer overflow of user QP buffer size

set_user_buf_size() computes the QP buffer size by left-shifting the
user-supplied rq.wqe_cnt and rq.wqe_shift values as signed integers.
A sufficiently large rq.wqe_cnt causes signed integer overflow, which
is undefined behavior, and yields a small or negative buf_size, causing
ib_umem_get() to map a buffer smaller than the hardware will actually
write into.

Replace the shifts and addition with check_shl_overflow() and
check_add_overflow(), rejecting invalid user inputs.

Moreover, guard the identical shift computing qp->sq.offset in
_create_user_qp() before set_user_buf_size() is reached.


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