From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To: selvin.xavier@broadcom.com, devesh.sharma@broadcom.com,
dledford@redhat.com, jgg@ziepe.ca, leon@kernel.org,
colin.king@canonical.com, roland@purestorage.com
Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-janitors@vger.kernel.org,
Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Subject: [PATCH] RDMA/ocrdma: Fix an off-by-one issue in 'ocrdma_add_stat'
Date: Sat, 28 Mar 2020 08:30:40 +0100 [thread overview]
Message-ID: <20200328073040.24429-1-christophe.jaillet@wanadoo.fr> (raw)
There is an off-by-one issue when checking if there is enough space in the
output buffer, because we must keep some place for a final '\0'.
While at it:
- Use 'scnprintf' instead of 'snprintf' in order to avoid a superfluous
'strlen'
- avoid some useless initializations
- avoida hard coded buffer size that can be computed at built time.
Fixes: a51f06e1679e ("RDMA/ocrdma: Query controller information")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
The '\0' comes from memset(..., 0, ...) in all callers.
This could be also avoided if needed.
---
drivers/infiniband/hw/ocrdma/ocrdma_stats.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_stats.c b/drivers/infiniband/hw/ocrdma/ocrdma_stats.c
index 5f831e3bdbad..614a449e6b87 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma_stats.c
+++ b/drivers/infiniband/hw/ocrdma/ocrdma_stats.c
@@ -49,13 +49,12 @@ static struct dentry *ocrdma_dbgfs_dir;
static int ocrdma_add_stat(char *start, char *pcur,
char *name, u64 count)
{
- char buff[128] = {0};
- int cpy_len = 0;
+ char buff[128];
+ int cpy_len;
- snprintf(buff, 128, "%s: %llu\n", name, count);
- cpy_len = strlen(buff);
+ cpy_len = scnprintf(buff, sizeof(buff), "%s: %llu\n", name, count);
- if (pcur + cpy_len > start + OCRDMA_MAX_DBGFS_MEM) {
+ if (pcur + cpy_len >= start + OCRDMA_MAX_DBGFS_MEM) {
pr_err("%s: No space in stats buff\n", __func__);
return 0;
}
--
2.20.1
next reply other threads:[~2020-03-28 7:30 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-28 7:30 Christophe JAILLET [this message]
2020-04-14 18:34 ` [PATCH] RDMA/ocrdma: Fix an off-by-one issue in 'ocrdma_add_stat' Jason Gunthorpe
2020-04-16 13:08 ` Dan Carpenter
2020-04-16 18:47 ` Jason Gunthorpe
2020-04-17 11:26 ` Dan Carpenter
2020-04-17 12:25 ` Jason Gunthorpe
2020-04-17 13:09 ` Dan Carpenter
2020-04-17 13:48 ` Jason Gunthorpe
2020-04-17 15:13 ` Dan Carpenter
2020-04-17 15:56 ` Jason Gunthorpe
2020-04-17 13:28 ` Marion & Christophe JAILLET
2020-04-17 13:50 ` Jason Gunthorpe
2020-04-17 14:39 ` Christophe JAILLET
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