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| author | Volodymyr G. Lukiianyk <volodymyrgl@gmail.com> | 2008-10-15 22:01:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-16 11:21:29 -0700 |
| commit | f4cfb18d7917ecb397b3497e931a2a23175709b7 (patch) | |
| tree | bb891b0f478e2ed7fa9dcefacc0b8342ce1b43d6 | |
| parent | 0c6aa2639ea83bfb7f91d72118bad70b3f60012a (diff) | |
| download | linux-f4cfb18d7917ecb397b3497e931a2a23175709b7.tar.gz | |
uclinux: fix gzip header parsing in binfmt_flat.c
There are off-by-one errors in decompress_exec() when calculating the length of
optional "original file name" and "comment" fields: the "ret" index is not
incremented when terminating '\0' character is reached. The check of the buffer
overflow (after an "extra-field" length was taken into account) is also fixed.
I've encountered this off-by-one error when tried to reuse
gzip-header-parsing part of the decompress_exec() function. There was an
"original file name" field in the payload (with miscalculated length) and
zlib_inflate() returned Z_DATA_ERROR. But after the fix similar to this
one all worked fine.
Signed-off-by: Volodymyr G Lukiianyk <volodymyrgl@gmail.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/binfmt_flat.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index dfc0197905ca..ccb781a6a804 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -229,13 +229,13 @@ static int decompress_exec( ret = 10; if (buf[3] & EXTRA_FIELD) { ret += 2 + buf[10] + (buf[11] << 8); - if (unlikely(LBUFSIZE == ret)) { + if (unlikely(LBUFSIZE <= ret)) { DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); goto out_free_buf; } } if (buf[3] & ORIG_NAME) { - for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) + while (ret < LBUFSIZE && buf[ret++] != 0) ; if (unlikely(LBUFSIZE == ret)) { DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); @@ -243,7 +243,7 @@ static int decompress_exec( } } if (buf[3] & COMMENT) { - for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) + while (ret < LBUFSIZE && buf[ret++] != 0) ; if (unlikely(LBUFSIZE == ret)) { DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); |