2022-05-23 08:13:41

by Christophe JAILLET

Subject: [PATCH] cgroup: Fix an error handling path in alloc_pagecache_max_30M()

If the first goto is taken, 'fd' is not opened yet (and is un-initialized).
So a direct return is safer.

Fixes: c1a31a2f7a9c ("cgroup: fix racy check in alloc_pagecache_max_30M() helper function")
Signed-off-by: Christophe JAILLET <[email protected]>
---
tools/testing/selftests/cgroup/test_memcontrol.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index c3d0d5f7b19c..8833359556f3 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -448,7 +448,7 @@ static int alloc_pagecache_max_30M(const char *cgroup, void *arg)
high = cg_read_long(cgroup, "memory.high");
max = cg_read_long(cgroup, "memory.max");
if (high != MB(30) && max != MB(30))
- goto cleanup;
+ return -1;

fd = get_temp_fd();
if (fd < 0)
--
2.34.1

2022-05-23 13:48:55

by David Vernet

Subject: Re: [PATCH] cgroup: Fix an error handling path in alloc_pagecache_max_30M()

On Sun, May 22, 2022 at 04:18:51PM +0200, Christophe JAILLET wrote:
> If the first goto is taken, 'fd' is not opened yet (and is un-initialized).
> So a direct return is safer.
>
> Fixes: c1a31a2f7a9c ("cgroup: fix racy check in alloc_pagecache_max_30M() helper function")
> Signed-off-by: Christophe JAILLET <[email protected]>
> ---
> tools/testing/selftests/cgroup/test_memcontrol.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
> index c3d0d5f7b19c..8833359556f3 100644
> --- a/tools/testing/selftests/cgroup/test_memcontrol.c
> +++ b/tools/testing/selftests/cgroup/test_memcontrol.c
> @@ -448,7 +448,7 @@ static int alloc_pagecache_max_30M(const char *cgroup, void *arg)
> high = cg_read_long(cgroup, "memory.high");
> max = cg_read_long(cgroup, "memory.max");
> if (high != MB(30) && max != MB(30))
> - goto cleanup;
> + return -1;
>
> fd = get_temp_fd();
> if (fd < 0)
> --
> 2.34.1
>

Acked-by: David Vernet <[email protected]>

2022-05-23 13:55:31

by Muchun Song

Subject: Re: [PATCH] cgroup: Fix an error handling path in alloc_pagecache_max_30M()

On Sun, May 22, 2022 at 04:18:51PM +0200, Christophe JAILLET wrote:
> If the first goto is taken, 'fd' is not opened yet (and is un-initialized).
> So a direct return is safer.
>
> Fixes: c1a31a2f7a9c ("cgroup: fix racy check in alloc_pagecache_max_30M() helper function")
> Signed-off-by: Christophe JAILLET <[email protected]>

Acked-by: Muchun Song <[email protected]>

Thanks.