From: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx> commit 5b0022dd32b7c2e15edf1827ba80aa1407edf9ff upstream. In register_ftrace_function_probe(), we are not checking the return value of alloc_and_copy_ftrace_hash(). The subsequent call to ftrace_match_records() may end up dereferencing the same. Add a check to ensure this doesn't happen. Link: http://lkml.kernel.org/r/26e92574f25ad23e7cafa3cf5f7a819de1832cbe.1562249521.git.naveen.n.rao@xxxxxxxxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Fixes: 1ec3a81a0cf42 ("ftrace: Have each function probe use its own ftrace_ops") Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/ftrace.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4317,6 +4317,11 @@ register_ftrace_function_probe(char *glo old_hash = *orig_hash; hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); + if (!hash) { + ret = -ENOMEM; + goto out; + } + ret = ftrace_match_records(hash, glob, strlen(glob)); /* Nothing found? */
