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| author | Chris Wright <chrisw@sous-sol.org> | 2010-09-09 16:34:59 -0700 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2010-09-09 22:43:49 -0400 |
| commit | df09162550fbb53354f0c88e85b5d0e6129ee9cc (patch) | |
| tree | e8ba6014c442cf72d587948733f8c29e0d330925 /kernel | |
| parent | 5e11637e2c929e34dcc0fbbfb48bdb638937701a (diff) | |
| download | lwn-df09162550fbb53354f0c88e85b5d0e6129ee9cc.tar.gz lwn-df09162550fbb53354f0c88e85b5d0e6129ee9cc.zip | |
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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ftrace.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 83a16e9ee518..fa7ece649fe1 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; } |