[PATCH] fprobe: Fix module reference count leak on error in register_fprobe()

[PATCH] fprobe: Fix module reference count leak on error in register_fprobe()

[Masami Hiramatsu (Google)]

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

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) <mhiramat@kernel.org>
---
 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])