Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH] [4/50] xtensa: prevent arbitrary read in ptrace | Date | Thu, 28 Jul 2011 16:44:08 -0700 (PDT) |
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2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Dan Rosenberg <drosenberg@vsecurity.com>
[ upstream commit 0d0138ebe24b94065580bd2601f8bb7eb6152f56 ]
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> Signed-off-by: Andi Kleen <ak@linux.intel.com>
Index: linux-2.6.35.y/arch/xtensa/kernel/ptrace.c =================================================================== --- linux-2.6.35.y.orig/arch/xtensa/kernel/ptrace.c +++ linux-2.6.35.y/arch/xtensa/kernel/ptrace.c @@ -147,6 +147,9 @@ int ptrace_setxregs(struct task_struct * 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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