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| author | Gao Xiang <hsiangkao@linux.alibaba.com> | 2022-12-05 18:00:50 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-31 15:31:59 +0300 |
| commit | 40c73b2ea9611b5388807be406f30f5e4e1162da (patch) | |
| tree | 3c54ecf3557f0bc45cab00ead2a01c9ca424bbf2 | |
| parent | 373b6f350aecf5dca2e7474f0b4ec8cca659f2f0 (diff) | |
| download | linux-40c73b2ea9611b5388807be406f30f5e4e1162da.tar.xz | |
erofs: validate the extent length for uncompressed pclusters
[ Upstream commit c505feba4c0d76084e56ec498ce819f02a7043ae ]
syzkaller reported a KASAN use-after-free:
https://syzkaller.appspot.com/bug?extid=2ae90e873e97f1faf6f2
The referenced fuzzed image actually has two issues:
- m_pa == 0 as a non-inlined pcluster;
- The logical length is longer than its physical length.
The first issue has already been addressed. This patch addresses
the second issue by checking the extent length validity.
Reported-by: syzbot+2ae90e873e97f1faf6f2@syzkaller.appspotmail.com
Fixes: 02827e1796b3 ("staging: erofs: add erofs_map_blocks_iter")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20221205150050.47784-2-hsiangkao@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/erofs/zmap.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index f49295b9f2e1..e6d5d7a18fb0 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -698,6 +698,11 @@ static int z_erofs_do_map_blocks(struct inode *inode, } if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN) { + if (map->m_llen > map->m_plen) { + DBG_BUGON(1); + err = -EFSCORRUPTED; + goto unmap_out; + } if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER) map->m_algorithmformat = Z_EROFS_COMPRESSION_INTERLACED; |