[ Upstream commit c42c0ffe81176940bd5dead474216b7198d77675 ]
syzkaller reported a memleak:
https://syzkaller.appspot.com/bug?id=62f37ff612f0021641eda5b17f056f1668aa9aed
unreferenced object 0xffff88811009c7f8 (size 136):
...
backtrace:
[<ffffffff821db19b>] z_erofs_do_read_page+0x99b/0x1740
[<ffffffff821dee9e>] z_erofs_readahead+0x24e/0x580
[<ffffffff814bc0d6>] read_pages+0x86/0x3d0
...
syzkaller constructed a case: in z_erofs_register_pcluster(),
ztailpacking = false and map->m_pa = zero. This makes pcl->obj.index be
zero although pcl is not a inline pcluster.
Then following path adds refcount for grp, but the refcount won't be put
because pcl is inline.
z_erofs_readahead()
z_erofs_do_read_page() # for another page
z_erofs_collector_begin()
erofs_find_workgroup()
erofs_workgroup_get()
Since it's illegal for the block address of a non-inlined pcluster to
be zero, add check here to avoid registering the pcluster which would
be leaked.
Fixes: cecf864d3d ("erofs: support inline data decompression")
Reported-by: syzbot+6f8cd9a0155b366d227f@syzkaller.appspotmail.com
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/Y42Kz6sVkf+XqJRB@debian
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
618e712b99