From: Dan Carpenter <dan.carpenter@oracle.com> stable inclusion from stable-5.10.70 commit 8cba4c2698e282aa03948b74ebc259925c873402 bugzilla: 182949 https://gitee.com/openeuler/kernel/issues/I4I3GQ Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 1bb30b20b49773369c299d4d6c65227201328663 ] After printing the list of thermal governors, then this function prints a newline character. The problem is that "size" has not been updated after printing the last governor. This means that it can write one character (the NUL terminator) beyond the end of the buffer. Get rid of the "size" variable and just use "PAGE_SIZE - count" directly. Fixes: 1b4f48494eb2 ("thermal: core: group functions related to governor handling") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/20210916131342.GB25094@kili Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- drivers/thermal/thermal_core.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index e669f83faa3c..17de8a9b991e 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -224,15 +224,14 @@ int thermal_build_list_of_policies(char *buf) { struct thermal_governor *pos; ssize_t count = 0; - ssize_t size = PAGE_SIZE; mutex_lock(&thermal_governor_lock); list_for_each_entry(pos, &thermal_governor_list, governor_list) { - size = PAGE_SIZE - count; - count += scnprintf(buf + count, size, "%s ", pos->name); + count += scnprintf(buf + count, PAGE_SIZE - count, "%s ", + pos->name); } - count += scnprintf(buf + count, size, "\n"); + count += scnprintf(buf + count, PAGE_SIZE - count, "\n"); mutex_unlock(&thermal_governor_lock); -- 2.20.1