Messages in this thread | | | Date | Fri, 8 Jul 2011 11:27:06 -0700 | From | Andrew Morton <> | Subject | Re: [Security] [PATCH] xtensa: prevent arbitrary read in ptrace |
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On Thu, 07 Jul 2011 20:03:54 -0400 Dan Rosenberg <drosenberg@vsecurity.com> wrote:
> Prevent an arbitrary kernel read. Check the user pointer with > access_ok() before copying data in. > > Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> > Cc: stable@kernel.org > --- > arch/xtensa/kernel/ptrace.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c > index c72c947..ddce75e 100644 > --- a/arch/xtensa/kernel/ptrace.c > +++ b/arch/xtensa/kernel/ptrace.c > @@ -147,6 +147,9 @@ int ptrace_setxregs(struct task_struct *child, void __user *uregs) > elf_xtregs_t *xtregs = uregs; > int ret = 0; > > + if (!access_ok(VERIFY_READ, uregs, sizeof(elf_xtregs_t))) > + return -EIO;
This should be -EFAULT, methinks?
> + > #if XTENSA_HAVE_COPROCESSORS > /* Flush all coprocessors before we overwrite them. */ > coprocessor_flush_all(ti);
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