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| author | Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> | 2008-11-07 00:08:19 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-11-13 09:55:57 -0800 |
| commit | a414c208c07d29b404d07665ea6ab1bc564ade42 (patch) | |
| tree | 9a896b0e59f9110879177ac57759b7caa473a63b | |
| parent | 4ad8ad6f94ed1eb8abcb5a4001cef9da92bc84c2 (diff) | |
| download | lwn-a414c208c07d29b404d07665ea6ab1bc564ade42.tar.gz lwn-a414c208c07d29b404d07665ea6ab1bc564ade42.zip | |
JFFS2: fix race condition in jffs2_lzo_compress()
commit dc8a0843a435b2c0891e7eaea64faaf1ebec9b11 upstream
deflate_mutex protects the globals lzo_mem and lzo_compress_buf. However,
jffs2_lzo_compress() unlocks deflate_mutex _before_ it has copied out the
compressed data from lzo_compress_buf. Correct this by moving the mutex
unlock after the copy.
In addition, document what deflate_mutex actually protects.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Richard Purdie <rpurdie@openedhand.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/jffs2/compr_lzo.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/fs/jffs2/compr_lzo.c b/fs/jffs2/compr_lzo.c index 47b045797e42..90cb60d09787 100644 --- a/fs/jffs2/compr_lzo.c +++ b/fs/jffs2/compr_lzo.c @@ -19,7 +19,7 @@ static void *lzo_mem; static void *lzo_compress_buf; -static DEFINE_MUTEX(deflate_mutex); +static DEFINE_MUTEX(deflate_mutex); /* for lzo_mem and lzo_compress_buf */ static void free_workspace(void) { @@ -49,18 +49,21 @@ static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out, mutex_lock(&deflate_mutex); ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem); - mutex_unlock(&deflate_mutex); - if (ret != LZO_E_OK) - return -1; + goto fail; if (compress_size > *dstlen) - return -1; + goto fail; memcpy(cpage_out, lzo_compress_buf, compress_size); - *dstlen = compress_size; + mutex_unlock(&deflate_mutex); + *dstlen = compress_size; return 0; + + fail: + mutex_unlock(&deflate_mutex); + return -1; } static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out, |