From ed8ec8f707ed4760c124d47b27c93df8ec5b1eba Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Mon, 12 May 2014 12:18:32 -0700 Subject: [PATCH] tcm_fc: Fix free-after-use regression in ft_free_cmd This patch fixes a free-after-use regression in ft_free_cmd(), where ft_sess_put() is called with cmd->sess after percpu_ida_free() has already released the tag. Fix this bug by saving the ft_sess pointer ahead of percpu_ida_free(), and pass it directly to ft_sess_put(). The regression was originally introduced in v3.13-rc1 commit: commit 5f544cfac956971099e906f94568bc3fd1a7108a Author: Nicholas Bellinger Date: Mon Sep 23 12:12:42 2013 -0700 tcm_fc: Convert to per-cpu command map pre-allocation of ft_cmd Reported-by: Jun Wu Cc: Mark Rustad Cc: Robert Love Cc: #3.13+ Signed-off-by: Nicholas Bellinger --- drivers/target/tcm_fc/tfc_cmd.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c index 01cf37f212c3..f5fd515b2bee 100644 --- a/drivers/target/tcm_fc/tfc_cmd.c +++ b/drivers/target/tcm_fc/tfc_cmd.c @@ -90,18 +90,18 @@ static void ft_free_cmd(struct ft_cmd *cmd) { struct fc_frame *fp; struct fc_lport *lport; - struct se_session *se_sess; + struct ft_sess *sess; if (!cmd) return; - se_sess = cmd->sess->se_sess; + sess = cmd->sess; fp = cmd->req_frame; lport = fr_dev(fp); if (fr_seq(fp)) lport->tt.seq_release(fr_seq(fp)); fc_frame_free(fp); - percpu_ida_free(&se_sess->sess_tag_pool, cmd->se_cmd.map_tag); - ft_sess_put(cmd->sess); /* undo get from lookup at recv */ + percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag); + ft_sess_put(sess); /* undo get from lookup at recv */ } void ft_release_cmd(struct se_cmd *se_cmd) -- 2.20.1