[PATCH] fprobe: Fix module reference count leak on error in register_fprobe()
"Masami Hiramatsu (Google)" <[email protected]> Wed, 29 Jul 2026 08:27:33 +0900
| Newsgroups | org.kernel.vger.linux-trace-kernel,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <178528125360.101985.4144133640239273153.stgit@devnote2> |
From: Masami Hiramatsu (Google) <[email protected]> In register_fprobe(), get_ips_from_filter() resolves target function addresses and increments module reference counts via try_module_get() for symbols in kernel modules. If get_ips_from_filter() fails on the second pass and returns an error, register_fprobe() returned directly without releasing module references acquired up to that point. Fix this by ensuring the cleanup loop executing module_put() runs even when get_ips_from_filter() returns a negative error. Fixes: d24fa977eec5 ("tracing: fprobe: Fix to lock module while registering fprobe") Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) <[email protected]> --- kernel/trace/fprobe.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index f215990b9061..f681015413b8 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -961,10 +961,8 @@ int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter return -ENOMEM; ret = get_ips_from_filter(filter, notfilter, addrs, mods, num); - if (ret < 0) - return ret; - - ret = register_fprobe_ips(fp, addrs, ret); + if (ret >= 0) + ret = register_fprobe_ips(fp, addrs, ret); for (int i = 0; i < num; i++) { if (mods[i])