From: Dan Carpenter Date: Fri, 21 Apr 2023 10:42:41 +0000 (+0300) Subject: coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f67bc15e526bb9920683ad6c1891ff9e08981335;p=linux.git coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet() 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: 75f4e3619fe2 ("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 --- diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 918d461fcf4a6..eaa296ced1678 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -942,7 +942,7 @@ 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;