Commit 0d0138eb authored Jul 25, 2011 by Dan Rosenberg Committed by Linus Torvalds Jul 25, 2011

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>

parent 67db392d

arch/xtensa/kernel/ptrace.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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);

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