From 6675880fc4b7c5137a2640b0725505c21b1ac525 Mon Sep 17 00:00:00 2001 From: Vamshi K Sthambamkadi Date: Fri, 8 Oct 2021 12:48:06 +0530 Subject: tracing: Fix memory leak in eprobe_register() kmemleak report: unreferenced object 0xffff900a70ec7ec0 (size 32): comm "ftracetest", pid 2770, jiffies 4295042510 (age 311.464s) hex dump (first 32 bytes): c8 31 23 45 0a 90 ff ff 40 85 c7 6e 0a 90 ff ff .1#E....@..n.... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000009d3751fd>] kmem_cache_alloc_trace+0x2a2/0x440 [<0000000088b8124b>] eprobe_register+0x1e3/0x350 [<000000002a9a0517>] __ftrace_event_enable_disable+0x7c/0x240 [<0000000019109321>] event_enable_write+0x93/0xe0 [<000000007d85b320>] vfs_write+0xb9/0x260 [<00000000b94c5e41>] ksys_write+0x67/0xe0 [<000000005a08c81d>] __x64_sys_write+0x1a/0x20 [<00000000240bf576>] do_syscall_64+0x3b/0xc0 [<0000000043d5d9f6>] entry_SYSCALL_64_after_hwframe+0x44/0xae unreferenced object 0xffff900a56bbf280 (size 128): comm "ftracetest", pid 2770, jiffies 4295042510 (age 311.464s) hex dump (first 32 bytes): ff ff ff ff ff ff ff ff 00 00 00 00 01 00 00 00 ................ 80 69 3b b2 ff ff ff ff 20 69 3b b2 ff ff ff ff .i;..... i;..... backtrace: [<000000009d3751fd>] kmem_cache_alloc_trace+0x2a2/0x440 [<00000000c4e90fad>] eprobe_register+0x1fc/0x350 [<000000002a9a0517>] __ftrace_event_enable_disable+0x7c/0x240 [<0000000019109321>] event_enable_write+0x93/0xe0 [<000000007d85b320>] vfs_write+0xb9/0x260 [<00000000b94c5e41>] ksys_write+0x67/0xe0 [<000000005a08c81d>] __x64_sys_write+0x1a/0x20 [<00000000240bf576>] do_syscall_64+0x3b/0xc0 [<0000000043d5d9f6>] entry_SYSCALL_64_after_hwframe+0x44/0xae In new_eprobe_trigger(), allocated edata and trigger variables are never freed. To fix, free memory in disable_eprobe(). Link: https://lkml.kernel.org/r/20211008071802.GA2098@cosmos Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Vamshi K Sthambamkadi Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_eprobe.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 3044b762cbd7..570d081929fb 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -632,6 +632,13 @@ static int disable_eprobe(struct trace_eprobe *ep, trace_event_trigger_enable_disable(file, 0); update_cond_flag(file); + + /* Make sure nothing is using the edata or trigger */ + tracepoint_synchronize_unregister(); + + kfree(edata); + kfree(trigger); + return 0; } -- cgit v1.2.3-59-g8ed1b