[PATCH 4.19 62/91] fail_function: Remove a redundant mutex unlock

Greg Kroah-Hartman
2020-11-23T12:32:42Z

From: Luo Meng <luomeng12@huawei.com>

[ Upstream commit 2801a5da5b25b7af9dd2addd19b2315c02d17b64 ]

Fix a mutex_unlock() issue where before copy_from_user() is
not called mutex_locked.

Fixes: 4b1a29a7f542 ("error-injection: Support fault injection framework")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/160570737118.263807.8358435412898356284.stgit@devnote2
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/fail_function.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/fail_function.c b/kernel/fail_function.c
index bc80a4e268c0b..a52151a2291fb 100644
--- a/kernel/fail_function.c
+++ b/kernel/fail_function.c
@@ -261,7 +261,7 @@ static ssize_t fei_write(struct file *file, const char __user *buffer,

if (copy_from_user(buf, buffer, count)) {
ret = -EFAULT;
- goto out;
+ goto out_free;
}
buf[count] = '\0';
sym = strstrip(buf);
@@ -315,8 +315,9 @@ static ssize_t fei_write(struct file *file, const char __user *buffer,
ret = count;
}
out:
- kfree(buf);
mutex_unlock(&fei_lock);
+out_free:
+ kfree(buf);
return ret;
}

--
2.27.0