xtensa: prevent arbitrary read in ptrace

Prevent an arbitrary kernel read.  Check the user pointer with access_ok()
before copying data in.

[akpm@linux-foundation.org: s/EIO/EFAULT/]
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: Christian Zankel <chris@zankel.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dan Rosenberg 2011-07-25 17:11:53 -07:00 committed by Linus Torvalds
parent 67db392d11
commit 0d0138ebe2

View File

@ -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 -EFAULT;
#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessors before we overwrite them. */
coprocessor_flush_all(ti);