From b247d8a62d2c964a6c81f869546c2914b8d0bb26 Mon Sep 17 00:00:00 2001 From: youngjun Date: Tue, 16 Jun 2020 17:30:43 +0900 Subject: [PATCH 1716/2944] ovl: inode reference leak in ovl_is_inuse true case. to #29273482 When "ovl_is_inuse" true case, trap inode reference not put. plus adding the comment explaining sequence of ovl_is_inuse after ovl_setup_trap. Fixes: 0be0bfd2de9d ("ovl: fix regression caused by overlapping layers detection") Cc: # v4.19+ Reviewed-by: Amir Goldstein Signed-off-by: youngjun Signed-off-by: Miklos Szeredi Link: https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git/commit/?h=overlayfs-next&id=24f14009b8f1754ec2ae4c168940c01259b0f88a Signed-off-by: Jeffle Xu Reviewed-by: Joseph Qi --- fs/overlayfs/super.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 131c846..624045c 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1322,14 +1322,23 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs, if (err < 0) goto out; + /* + * Check if lower root conflicts with this overlay layers before + * checking if it is in-use as upperdir/workdir of "another" + * mount, because we do not bother to check in ovl_is_inuse() if + * the upperdir/workdir is in fact in-use by our + * upperdir/workdir. + */ err = ovl_setup_trap(sb, stack[i].dentry, &trap, "lowerdir"); if (err) goto out; if (ovl_is_inuse(stack[i].dentry)) { err = ovl_report_in_use(ofs, "lowerdir"); - if (err) + if (err) { + iput(trap); goto out; + } } mnt = clone_private_mount(&stack[i]); -- 1.8.3.1