From: Vamshi K Sthambamkadi vamshi.k.sthambamkadi@gmail.com

kmemleak report: [<57dcc2ca>] __kmalloc_track_caller+0x139/0x2b0 [<f1c45d0f>] kstrndup+0x37/0x80 [<f9761eb0>] parse_probe_arg.isra.7+0x3cc/0x630 [<055bf2ba>] traceprobe_parse_probe_arg+0x2f5/0x810 [<655a7766>] trace_kprobe_create+0x2ca/0x950 [<4fc6a02a>] create_or_delete_trace_kprobe+0xf/0x30 [<6d1c8a52>] trace_run_command+0x67/0x80 [<be812cc0>] trace_parse_run_command+0xa7/0x140 [<aecfe401>] probes_write+0x10/0x20 [<2027641c>] __vfs_write+0x30/0x1e0 [<6a4aeee1>] vfs_write+0x96/0x1b0 [<3517fb7d>] ksys_write+0x53/0xc0 [<dad91db7>] __ia32_sys_write+0x15/0x20 [<da347f64>] do_syscall_32_irqs_on+0x3d/0x260 [<fd0b7e7d>] do_fast_syscall_32+0x39/0xb0 [<ea5ae810>] entry_SYSENTER_32+0xaf/0x102

Post parse_probe_arg(), the FETCH_OP_DATA operation type is overwritten to FETCH_OP_ST_STRING, as a result memory is never freed since traceprobe_free_probe_arg() iterates only over SYMBOL and DATA op types

Setup fetch string operation correctly after fetch_op_data operation.

Link: https://lkml.kernel.org/r/20200615143034.GA1734@cosmos

Cc: stable@vger.kernel.org Fixes: a42e3c4de964 ("tracing/probe: Add immediate string parameter support") Acked-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Vamshi K Sthambamkadi vamshi.k.sthambamkadi@gmail.com Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org --- kernel/trace/trace_probe.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index b8a928e925c7..d2867ccc6aca 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -639,8 +639,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, ret = -EINVAL; goto fail; } - if ((code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM) || - parg->count) { + if ((code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || + code->op == FETCH_OP_DATA) || parg->count) { /* * IMM, DATA and COMM is pointing actual address, those * must be kept, and if parg->count != 0, this is an