diff options
| author | Gao Xiang <gaoxiang25@huawei.com> | 2019-08-19 18:34:26 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-08-21 05:44:07 -0700 |
| commit | 598bb8913d015150b7734b55443c0e53e7189fc7 (patch) | |
| tree | 1dde1ef92aad42f83ee7b196086aa8672815d4e0 /drivers | |
| parent | 138e1a0990e80db486ab9f6c06bd5c01f9a97999 (diff) | |
staging: erofs: avoid endless loop of invalid lookback distance 0
As reported by erofs-utils fuzzer, Lookback distance should
be a positive number, so it should be actually looked back
rather than spinning.
Fixes: 02827e1796b3 ("staging: erofs: add erofs_map_blocks_iter")
Cc: <stable@vger.kernel.org> # 4.19+
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20190819103426.87579-7-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/staging/erofs/zmap.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/staging/erofs/zmap.c b/drivers/staging/erofs/zmap.c index 7408e86823a4..774dacbc5b32 100644 --- a/drivers/staging/erofs/zmap.c +++ b/drivers/staging/erofs/zmap.c @@ -350,6 +350,12 @@ static int vle_extent_lookback(struct z_erofs_maprecorder *m, switch (m->type) { case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD: + if (unlikely(!m->delta[0])) { + errln("invalid lookback distance 0 at nid %llu", + vi->nid); + DBG_BUGON(1); + return -EFSCORRUPTED; + } return vle_extent_lookback(m, m->delta[0]); case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN: map->m_flags &= ~EROFS_MAP_ZIPPED; |