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Date:   Tue, 24 Sep 2019 08:14:52 +0200
From:   Pavel Machek <pavel@ucw.cz>
To:     clm@fb.com, josef@toxicpanda.com, dsterba@suse.com,
        linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] btrfs compression: check string length
Message-ID: <20190924061452.GA31397@amd>
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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 <pavel@denx.de>

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 =3D 1; i < ARRAY_SIZE(btrfs_compress_types); i++) {
 		size_t comp_len =3D strlen(btrfs_compress_types[i]);
=20
-		if (len < comp_len)
+		if (len !=3D comp_len)
 			continue;
=20
 		if (!strncmp(btrfs_compress_types[i], str, comp_len))

--=20
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo=
g.html

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