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| author |   Christian Brauner <christian.brauner@ubuntu.com> | 2021-07-14 15:47:50 +0200 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-14 09:19:06 -0700 |
| commit | d1d488d813703618f0dd93f0e4c4a05928114aa8 (patch) | |
| tree | b1115033156bb1945244b3000489d84a4b5a68ee /kernel/cgroup/cgroup-v1.c | |
| parent | cgroup: verify that source is a string (diff) | |
| download | linux-dev-d1d488d813703618f0dd93f0e4c4a05928114aa8.tar.xz linux-dev-d1d488d813703618f0dd93f0e4c4a05928114aa8.zip | |
fs: add vfs_parse_fs_param_source() helper
Add a simple helper that filesystems can use in their parameter parser
to parse the "source" parameter. A few places open-coded this function
and that already caused a bug in the cgroup v1 parser that we fixed.
Let's make it harder to get this wrong by introducing a helper which
performs all necessary checks.
Link: https://syzkaller.appspot.com/bug?id=6312526aba5beae046fdae8f00399f87aab48b12
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | kernel/cgroup/cgroup-v1.c | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 527917c0b30b..8d6bf56ed77a 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -911,15 +911,11 @@ int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param) opt = fs_parse(fc, cgroup1_fs_parameters, param, &result); if (opt == -ENOPARAM) { - if (strcmp(param->key, "source") == 0) { - if (param->type != fs_value_is_string) - return invalf(fc, "Non-string source"); - if (fc->source) - return invalf(fc, "Multiple sources not supported"); - fc->source = param->string; - param->string = NULL; - return 0; - } + int ret; + + ret = vfs_parse_fs_param_source(fc, param); + if (ret != -ENOPARAM) + return ret; for_each_subsys(ss, i) { if (strcmp(param->key, ss->legacy_name)) continue; |