wireguard-linux/fs/overlayfs/params.c, branch jd/bump-compilers

ovl: ovl_parse_param_lowerdir: Add missed '\n' for pr_err

2024-08-23T17:58:59Z

Add '\n' for pr_err in function ovl_parse_param_lowerdir(), which ensures that error message is displayed at once. Fixes: b36a5780cb44 ("ovl: modify layer parameter parsing") Signed-off-by: Zhihao Cheng Link: https://lore.kernel.org/r/20240705011510.794025-4-chengzhihao1@huawei.com Signed-off-by: Christian Brauner

ovl: fix wrong lowerdir number check for parameter Opt_lowerdir

2024-08-23T17:56:38Z

The max count of lowerdir is OVL_MAX_STACK[500], which is broken by commit 37f32f526438("ovl: fix memory leak in ovl_parse_param()") for parameter Opt_lowerdir. Since commit 819829f0319a("ovl: refactor layer parsing helpers") and commit 24e16e385f22("ovl: add support for appending lowerdirs one by one") added check ovl_mount_dir_check() in function ovl_parse_param_lowerdir(), the 'ctx->nr' should be smaller than OVL_MAX_STACK, after commit 37f32f526438("ovl: fix memory leak in ovl_parse_param()") is applied, the 'ctx->nr' is updated before the check ovl_mount_dir_check(), which leads the max count of lowerdir to become 499 for parameter Opt_lowerdir. Fix it by replacing lower layers parsing code with the existing helper function ovl_parse_layer(). Fixes: 37f32f526438 ("ovl: fix memory leak in ovl_parse_param()") Signed-off-by: Zhihao Cheng Link: https://lore.kernel.org/r/20240705011510.794025-3-chengzhihao1@huawei.com Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner

ovl: pass string to ovl_parse_layer()

2024-08-23T17:56:38Z

So it can be used for parsing the Opt_lowerdir. Signed-off-by: Zhihao Cheng Link: https://lore.kernel.org/r/20240705011510.794025-2-chengzhihao1@huawei.com Signed-off-by: Christian Brauner

fs_parser: move fsparam_string_empty() helper into header

2024-03-26T08:01:18Z

Since both ext4 and overlayfs define the same macro to specify string parameters that may allow empty values, define it in an header file so that this helper can be shared. Signed-off-by: Luis Henriques (SUSE) Link: https://lore.kernel.org/r/20240312104757.27333-1-luis.henriques@linux.dev Signed-off-by: Christian Brauner

ovl: Always reject mounting over case-insensitive directories

2024-02-27T21:55:34Z

overlayfs relies on the filesystem setting DCACHE_OP_HASH or DCACHE_OP_COMPARE to reject mounting over case-insensitive directories. Since commit bb9cd9106b22 ("fscrypt: Have filesystems handle their d_ops"), we set ->d_op through a hook in ->d_lookup, which means the root dentry won't have them, causing the mount to accidentally succeed. In v6.7-rc7, the following sequence will succeed to mount, but any dentry other than the root dentry will be a "weird" dentry to ovl and fail with EREMOTE. mkfs.ext4 -O casefold lower.img mount -O loop lower.img lower mount -t overlay -o lowerdir=lower,upperdir=upper,workdir=work ovl /mnt Mounting on a subdirectory fails, as expected, because DCACHE_OP_HASH and DCACHE_OP_COMPARE are properly set by ->lookup. Fix by explicitly rejecting superblocks that allow case-insensitive dentries. Yes, this will be solved when we move d_op configuration back to ->s_d_op. Yet, we better have an explicit fix to avoid messing up again. While there, re-sort the entries to have more descriptive error messages first. Fixes: bb9cd9106b22 ("fscrypt: Have filesystems handle their d_ops") Acked-by: Amir Goldstein Reviewed-by: Eric Biggers Link: https://lore.kernel.org/r/20240221171412.10710-2-krisman@suse.de Signed-off-by: Gabriel Krisman Bertazi

ovl: remove redundant ofs->indexdir member

2023-11-20T07:49:09Z

When the index feature is disabled, ofs->indexdir is NULL. When the index feature is enabled, ofs->indexdir has the same value as ofs->workdir and takes an extra reference. This makes the code harder to understand when it is not always clear that ofs->indexdir in one function is the same dentry as ofs->workdir in another function. Remove this redundancy, by referencing ofs->workdir directly in index helpers and by using the ovl_indexdir() accessor in generic code. Signed-off-by: Amir Goldstein

ovl: fix memory leak in ovl_parse_param()

2023-11-14T06:09:36Z

On failure to parse parameters in ovl_parse_param_lowerdir(), it is necessary to update ctx->nr with the correct nr before using ovl_reset_lowerdirs() to release l->name. Reported-and-tested-by: syzbot+26eedf3631650972f17c@syzkaller.appspotmail.com Fixes: c835110b588a ("ovl: remove unused code in lowerdir param parsing") Co-authored-by: Edward Adam Davis Signed-off-by: Amir Goldstein

ovl: add support for appending lowerdirs one by one

2023-10-30T22:13:02Z

Add new mount options lowerdir+ and datadir+ that can be used to add layers to lower layers stack one by one. Unlike the legacy lowerdir mount option, special characters (i.e. colons and cammas) are not unescaped with these new mount options. The new mount options can be repeated to compose a large stack of lower layers, but they may not be mixed with the lagacy lowerdir mount option, because for displaying lower layers in mountinfo, we do not want to mix escaped with unescaped lower layers path syntax. Similar to data-only layer rules with the lowerdir mount option, the datadir+ option must follow at least one lowerdir+ option and the lowerdir+ option must not follow the datadir+ option. If the legacy lowerdir mount option follows lowerdir+ and datadir+ mount options, it overrides them. Sepcifically, calling: fsconfig(FSCONFIG_SET_STRING, "lowerdir", "", 0); can be used to reset previously setup lower layers. Suggested-by: Miklos Szeredi Link: https://lore.kernel.org/r/CAJfpegt7VC94KkRtb1dfHG8+4OzwPBLYqhtc8=QFUxpFJE+=RQ@mail.gmail.com/ Signed-off-by: Amir Goldstein

ovl: refactor layer parsing helpers

2023-10-30T22:13:02Z

In preparation for new mount options to add lowerdirs one by one, generalize ovl_parse_param_upperdir() into helper ovl_parse_layer() that will be used for parsing a single lower layers. Suggested-by: Miklos Szeredi Link: https://lore.kernel.org/r/CAJfpegt7VC94KkRtb1dfHG8+4OzwPBLYqhtc8=QFUxpFJE+=RQ@mail.gmail.com/ Signed-off-by: Amir Goldstein

ovl: store and show the user provided lowerdir mount option

2023-10-30T22:13:02Z

We are about to add new mount options for adding lowerdir one by one, but those mount options will not support escaping. For the existing case, where lowerdir mount option is provided as a colon separated list, store the user provided (possibly escaped) string and display it as is when showing the lowerdir mount option. Signed-off-by: Amir Goldstein