On Fri, Jul 06, 2018 at 10:48:03PM +0200, Jann Horn wrote: > In general, accessing userspace memory beyond the length of the supplied > buffer in VFS read/write handlers can lead to both kernel memory corruption > (via kernel_read()/kernel_write(), which can e.g. be triggered via > sys_splice()) and privilege escalation inside userspace. > > In this case, the affected files are in debugfs (and should therefore only > be accessible to root), and the read handlers check that *pos is zero > (meaning that at least sys_splice() can't trigger kernel memory > corruption). Because of the root requirement, this is not a security fix, > but rather a cleanup. > > For the read handlers, fix it by using simple_read_from_buffer() instead of > custom logic. Add min() calls to the write handlers. > > changed in v2: > - also fix write handlers
No changelog in commit messages, please
>
> Fixes: 4a2da0b8c078 ("IB/mlx5: Add debug control parameters for congestion
> control")
> Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
> Signed-off-by: Jann Horn <ja...@google.com>
> ---
> drivers/infiniband/hw/mlx5/cong.c | 9 +--------
> drivers/infiniband/hw/mlx5/mr.c | 32 ++++++++-----------------------
> 2 files changed, 9 insertions(+), 32 deletions(-)
>
Thanks,
Reviewed-by: Leon Romanovsky <leo...@mellanox.com>
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