2019-09-26 00:42:00

by Pavel Machek

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Subject: [PATCH] btrfs compression: check string length

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AFAICT, with current code user could pass something like "lzox" and
still get "lzo" compression. Check string lengths to prevent that.

Signed-off-by: Pavel Machek <[email protected]>

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index b05b361..1083ab4 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -51,7 +51,7 @@ bool btrfs_compress_is_valid_type(const char *str, size_t len)
for (i = 1; i < ARRAY_SIZE(btrfs_compress_types); i++) {
size_t comp_len = strlen(btrfs_compress_types[i]);

- if (len < comp_len)
+ if (len != comp_len)
continue;

if (!strncmp(btrfs_compress_types[i], str, comp_len))

--
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2019-09-26 00:44:49

by Nikolay Borisov

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Subject: Re: [PATCH] btrfs compression: check string length

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On 24.09.19 г. 9:14 ч., Pavel Machek wrote:
> AFAICT, with current code user could pass something like "lzox" and
> still get "lzo" compression. Check string lengths to prevent that.
>
> Signed-off-by: Pavel Machek <[email protected]>
>
> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> index b05b361..1083ab4 100644
> --- a/fs/btrfs/compression.c
> +++ b/fs/btrfs/compression.c
> @@ -51,7 +51,7 @@ bool btrfs_compress_is_valid_type(const char *str, size_t len)
> for (i = 1; i < ARRAY_SIZE(btrfs_compress_types); i++) {
> size_t comp_len = strlen(btrfs_compress_types[i]);
>
> - if (len < comp_len)
> + if (len != comp_len)
> continue;

It's like that so that we can support compression strings such as
zlib:9. In fact the initial version was written like you suggest:

https://www.mail-archive.com/[email protected]/msg88216.html

>
> if (!strncmp(btrfs_compress_types[i], str, comp_len))
>