From 0d0138ebe24b94065580bd2601f8bb7eb6152f56 Mon Sep 17 00:00:00 2001 From: Dan Rosenberg Date: Mon, 25 Jul 2011 17:11:53 -0700 Subject: [PATCH] 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 Cc: Christian Zankel Cc: Oleg Nesterov Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/xtensa/kernel/ptrace.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c index c72c947..a0d042a 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 -EFAULT; + #if XTENSA_HAVE_COPROCESSORS /* Flush all coprocessors before we overwrite them. */ coprocessor_flush_all(ti); -- 2.7.4