4.18-stable review patch. If anyone has any objections, please let me know.
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From: Amir Goldstein amir73il@gmail.com
commit babf4770be0adc69e6d2de150f4040f175e24beb upstream.
We hit a BUG on kfree of an ERR_PTR()...
Reported-by: syzbot+ff03fe05c717b82502d0@syzkaller.appspotmail.com Fixes: 8b88a2e64036 ("ovl: verify upper root dir matches lower root dir") Cc: stable@vger.kernel.org # v4.13 Signed-off-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/overlayfs/namei.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -441,8 +441,10 @@ int ovl_verify_set_fh(struct dentry *den
fh = ovl_encode_real_fh(real, is_upper); err = PTR_ERR(fh); - if (IS_ERR(fh)) + if (IS_ERR(fh)) { + fh = NULL; goto fail; + }
err = ovl_verify_fh(dentry, name, fh); if (set && err == -ENODATA)