xfrm: Reset secpath in xfrm failure

xfrm: Reset secpath in xfrm failure

[ Upstream commit 6ed69184ed9c43873b8a1ee721e3bf3c08c2c6be ]

In esp4_gro_receive() and esp6_gro_receive(), secpath can be allocated
without adding xfrm state to xvec. Then, sp->xvec[sp->len - 1] would
fail and result in dereferencing invalid pointer in esp4_gso_segment()
and esp6_gso_segment(). Reset secpath if xfrm function returns error.

Fixes: 7785bba299a8 ("esp: Add a software GRO codepath")
Reported-by: syzbot+b69368fd933c6c592f4c@syzkaller.appspotmail.com
Signed-off-by: Myungho Jung <mhjungk@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>