Messages in this thread Patch in this message | | | Date | Sat, 30 Oct 2010 19:40:02 +0400 | From | Vasiliy Kulikov <> | Subject | Re: [PATCH] ipc: shm: fix information leak to userland |
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Hi Dan,
On Sat, Oct 30, 2010 at 11:00 -0400, Dan Rosenberg wrote: > This one already got taken care of by Kees Cook: > > http://lkml.org/lkml/2010/10/6/486
After 25 days it is still not in linux-next. Also the second hunk is IMO odd as all five fields are initialized:
case IPC_OLD: { struct shminfo out;
if(in->shmmax > INT_MAX) out.shmmax = INT_MAX; else out.shmmax = (int)in->shmmax;
out.shmmin = in->shmmin; out.shmmni = in->shmmni; out.shmseg = in->shmseg; out.shmall = in->shmall;
return copy_to_user(buf, &out, sizeof(out)); }
/* Obsolete, used only for backwards compatibility */ struct shminfo { int shmmax; int shmmin; int shmmni; int shmseg; int shmall; };
And I see no padding hole in shminfo.
> Thanks, > Dan > > > Structure shmid_ds is copied to userland with shm_unused{,2,3} > > fields unitialized. It leads to leaking of contents of kernel stack > > memory. > > Cc: stable@kernel.org > > Acked-by: Al Viro <viro@ZenIV.linux.org.uk> > > Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> > > --- > > Compile tested. > > ipc/shm.c | 1 + > > 1 files changed, 1 insertions(+), 0 deletions(-) > > diff --git a/ipc/shm.c b/ipc/shm.c > > index fd658a1..7d3bb22 100644 > > --- a/ipc/shm.c > > +++ b/ipc/shm.c > > @@ -479,6 +479,7 @@ static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ > > { > > struct shmid_ds out; > > > > + memset(&out, 0, sizeof(out)); > > ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); > > out.shm_segsz = in->shm_segsz; > > out.shm_atime = in->shm_atime; > >
Thanks,
-- Vasiliy
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