Messages in this thread | | | From | Saeed Mahameed <> | Subject | Re: [PATCH net v2] net/mlx5: fix uaccess beyond "count" in debugfs read/write handlers | Date | Wed, 11 Jul 2018 19:10:38 +0000 |
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On Fri, 2018-07-06 at 22:18 +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 check that *pos is zero (which prevents > the > sys_splice() trick). Therefore, this is not a security fix, but > rather a > small cleanup. > > For the read handlers, fix it by using simple_read_from_buffer() > instead of > custom logic. > For the write handler, add a check. > > changed in v2: > - also fix dbg_write() > > Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB > adapters") > Signed-off-by: Jann Horn <jannh@google.com> >
Applied to mlx5-next, Thanks!!
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