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authorChris Wright <chrisw@sous-sol.org>2010-09-09 16:34:59 -0700
committerSteven Rostedt <rostedt@goodmis.org>2010-09-09 22:43:49 -0400
commitdf09162550fbb53354f0c88e85b5d0e6129ee9cc (patch)
treee8ba6014c442cf72d587948733f8c29e0d330925
parent5e11637e2c929e34dcc0fbbfb48bdb638937701a (diff)
downloadlinux-linaro-df09162550fbb53354f0c88e85b5d0e6129ee9cc.tar.gz
tracing: t_start: reset FTRACE_ITER_HASH in case of seek/pread
Be sure to avoid entering t_show() with FTRACE_ITER_HASH set without having properly started the iterator to iterate the hash. This case is degenerate and, as discovered by Robert Swiecki, can cause t_hash_show() to misuse a pointer. This causes a NULL ptr deref with possible security implications. Tracked as CVE-2010-3079. Cc: Robert Swiecki <swiecki@google.com> Cc: Eugene Teo <eugene@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/ftrace.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 83a16e9ee51..fa7ece649fe 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1510,6 +1510,8 @@ static void *t_start(struct seq_file *m, loff_t *pos)
if (*pos > 0)
return t_hash_start(m, pos);
iter->flags |= FTRACE_ITER_PRINTALL;
+ /* reset in case of seek/pread */
+ iter->flags &= ~FTRACE_ITER_HASH;
return iter;
}