From: Xiubo Li <lixiubo@xxxxxxxxxxxxxxxxxxxx> For all the entries allocated from the ring cmd area, the memory is something like the stack, which will reserve the old data, so the entry->req.iov_bidi_cnt maybe none zero. To fix this, just memset all the entry memory before using it, and also to be more readable we adjust the bidi code. Fixed: fe25cc34795(tcmu: Recalculate the tcmu_cmd size to save cmd area memories) Reported-by: Bryant G. Ly <bryantly@xxxxxxxxxxxxxxxxxx> Signed-off-by: Xiubo Li <lixiubo@xxxxxxxxxxxxxxxxxxxx> --- drivers/target/target_core_user.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 2f1fa92..be62c86 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -840,6 +840,7 @@ static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd, } entry = (void *) mb + CMDR_OFF + cmd_head; + memset(entry, 0, command_size); tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD); entry->hdr.cmd_id = tcmu_cmd->cmd_id; entry->hdr.kflags = 0; @@ -865,8 +866,8 @@ static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd, entry->req.iov_dif_cnt = 0; /* Handle BIDI commands */ + iov_cnt = 0; if (se_cmd->se_cmd_flags & SCF_BIDI) { - iov_cnt = 0; iov++; ret = scatter_data_area(udev, tcmu_cmd, se_cmd->t_bidi_data_sg, @@ -879,8 +880,8 @@ static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd, pr_err("tcmu: alloc and scatter bidi data failed\n"); return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } - entry->req.iov_bidi_cnt = iov_cnt; } + entry->req.iov_bidi_cnt = iov_cnt; /* * Recalaulate the command's base size and size according -- 1.8.3.1