From af9f62c1686268c0517b289274d38f3a03bebd2a Mon Sep 17 00:00:00 2001 From: David Disseldorp Date: Fri, 23 Dec 2016 11:37:55 +0100 Subject: [PATCH] target: bounds check XCOPY segment descriptor list Check the length of the XCOPY request segment descriptor list against the value advertised via the MAXIMUM SEGMENT DESCRIPTOR COUNT field in the RECEIVE COPY OPERATING PARAMETERS response. spc4r37 6.4.3.5 states: If the number of segment descriptors exceeds the allowed number, the copy manager shall terminate the command with CHECK CONDITION status, with the sense key set to ILLEGAL REQUEST, and the additional sense code set to TOO MANY SEGMENT DESCRIPTORS. This functionality is testable using the libiscsi ExtendedCopy.DescrLimits test. Signed-off-by: David Disseldorp Reviewed-by: Christoph Hellwig Signed-off-by: Bart Van Assche --- drivers/target/target_core_xcopy.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c index db265ad10fa4..da0f2da732e7 100644 --- a/drivers/target/target_core_xcopy.c +++ b/drivers/target/target_core_xcopy.c @@ -308,17 +308,26 @@ static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd, struct xcopy_op *xop, unsigned char *p, - unsigned int sdll) + unsigned int sdll, sense_reason_t *sense_ret) { unsigned char *desc = p; unsigned int start = 0; int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0; + *sense_ret = TCM_INVALID_PARAMETER_LIST; + if (offset != 0) { pr_err("XCOPY segment descriptor list length is not" " multiple of %d\n", XCOPY_SEGMENT_DESC_LEN); return -EINVAL; } + if (sdll > RCR_OP_MAX_SG_DESC_COUNT * XCOPY_SEGMENT_DESC_LEN) { + pr_err("XCOPY supports %u segment descriptor(s), sdll: %u too" + " large..\n", RCR_OP_MAX_SG_DESC_COUNT, sdll); + /* spc4r37 6.4.3.5 SEGMENT DESCRIPTOR LIST LENGTH field */ + *sense_ret = TCM_TOO_MANY_SEGMENT_DESCS; + return -EINVAL; + } while (start < sdll) { /* @@ -916,7 +925,8 @@ sense_reason_t target_do_xcopy(struct se_cmd *se_cmd) seg_desc = &p[16]; seg_desc += (rc * XCOPY_TARGET_DESC_LEN); - rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc, sdll); + rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc, + sdll, &ret); if (rc <= 0) { xcopy_pt_undepend_remotedev(xop); goto out; -- 2.39.5