From: Dan Rosenberg <drosenberg@vsecurity.com>
To: chris@zankel.net
Cc: linux-kernel@vger.kernel.org, security@kernel.org
Subject: [PATCH] xtensa: prevent arbitrary read in ptrace
Date: Thu, 07 Jul 2011 20:03:54 -0400 [thread overview]
Message-ID: <1310083434.2139.4.camel@anubis> (raw)
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;
+
#if XTENSA_HAVE_COPROCESSORS
/* Flush all coprocessors before we overwrite them. */
coprocessor_flush_all(ti);
next reply other threads:[~2011-07-08 0:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-08 0:03 Dan Rosenberg [this message]
2011-07-08 18:27 ` [Security] [PATCH] xtensa: prevent arbitrary read in ptrace Andrew Morton
2011-07-08 18:42 ` Oleg Nesterov
2011-07-08 19:29 ` Chris Zankel
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