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authorDan Rosenberg <drosenberg@vsecurity.com>2011-07-25 17:11:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-25 20:57:07 -0700
commit0d0138ebe24b94065580bd2601f8bb7eb6152f56 (patch)
tree13ab981dbddd25b57bb821394d0a3c78bf8fb25a
parent67db392d1124e14684e23deb572de2a63b9b3b69 (diff)
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>
-rw-r--r--arch/xtensa/kernel/ptrace.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index c72c9473ef99..a0d042aa2967 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);