From 4f00109e592fc07f40c6db4d42dfd5a5d43f414f Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 21 Apr 2023 13:42:41 +0300 Subject: [PATCH] coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet() commit f67bc15e526bb9920683ad6c1891ff9e08981335 upstream. This code generates a Smatch warning: drivers/hwtracing/coresight/coresight-tmc-etr.c:947 tmc_etr_buf_insert_barrier_packet() error: uninitialized symbol 'bufp'. The problem is that if tmc_sg_table_get_data() returns -EINVAL, then when we test if "len < CORESIGHT_BARRIER_PKT_SIZE", the negative "len" value is type promoted to a high unsigned long value which is greater than CORESIGHT_BARRIER_PKT_SIZE. Fix this bug by adding an explicit check for error codes. Fixes: 6035fcaa30da ("coresight: tmc-etr: Add transparent buffer management") Signed-off-by: Dan Carpenter Signed-off-by: Suzuki K Poulose Link: https://lore.kernel.org/r/7d33e244-d8b9-4c27-9653-883a13534b01@kili.mountain Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index ed77c7f7b344b..763463776a0e1 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -909,7 +909,7 @@ tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset) len = tmc_etr_buf_get_data(etr_buf, offset, CORESIGHT_BARRIER_PKT_SIZE, &bufp); - if (WARN_ON(len < CORESIGHT_BARRIER_PKT_SIZE)) + if (WARN_ON(len < 0 || len < CORESIGHT_BARRIER_PKT_SIZE)) return -EINVAL; coresight_insert_barrier_packet(bufp); return offset + CORESIGHT_BARRIER_PKT_SIZE; -- 2.39.5