From: Ronnie Sahlberg <lsahlber@redhat.com>
Date: Fri, 18 Jun 2021 10:58:30 +1000
Subject: [PATCH] cifs: avoid extra calls in posix_info_parse
Git-commit: ca38fabc31ecf8a2cd14ff92a68936db59106409
Patch-mainline: v5.14-rc1
References: bsc#1192606
In posix_info_parse() we call posix_info_sid_size twice for each of the owner and the group
sid. The first time to check that it is valid, i.e. >= 0 and the second time
to just pass it in as a length to memcpy().
As this is a pure function we know that it can not be negative the second time and this
is technically a false warning in coverity.
However, as it is a pure function we are just wasting cycles by calling it a second time.
Record the length from the first time we call it and save some cycles as well as make
Coverity happy.
Addresses-Coverity-ID: 1491379 ("Argument can not be negative")
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
fs/cifs/smb2pdu.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index c205f93e0a10..4a244cc4e902 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -4498,7 +4498,7 @@ int posix_info_parse(const void *beg, const void *end,
{
int total_len = 0;
- int sid_len;
+ int owner_len, group_len;
int name_len;
const void *owner_sid;
const void *group_sid;
@@ -4521,17 +4521,17 @@ int posix_info_parse(const void *beg, const void *end,
/* check owner sid */
owner_sid = beg + total_len;
- sid_len = posix_info_sid_size(owner_sid, end);
- if (sid_len < 0)
+ owner_len = posix_info_sid_size(owner_sid, end);
+ if (owner_len < 0)
return -1;
- total_len += sid_len;
+ total_len += owner_len;
/* check group sid */
group_sid = beg + total_len;
- sid_len = posix_info_sid_size(group_sid, end);
- if (sid_len < 0)
+ group_len = posix_info_sid_size(group_sid, end);
+ if (group_len < 0)
return -1;
- total_len += sid_len;
+ total_len += group_len;
/* check name len */
if (beg + total_len + 4 > end)
@@ -4552,10 +4552,8 @@ int posix_info_parse(const void *beg, const void *end,
out->size = total_len;
out->name_len = name_len;
out->name = name;
- memcpy(&out->owner, owner_sid,
- posix_info_sid_size(owner_sid, end));
- memcpy(&out->group, group_sid,
- posix_info_sid_size(group_sid, end));
+ memcpy(&out->owner, owner_sid, owner_len);
+ memcpy(&out->group, group_sid, group_len);
}
return total_len;
}
--
2.33.1