From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Ilya Maximets <i.maximets@samsung.com>,
Magnus Karlsson <magnus.karlsson@intel.com>,
Andrii Nakryiko <andriin@fb.com>,
Alexei Starovoitov <ast@kernel.org>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: [PATCH AUTOSEL 5.2 036/123] libbpf: fix using uninitialized ioctl results
Date: Tue, 13 Aug 2019 22:09:20 -0400 [thread overview]
Message-ID: <20190814021047.14828-36-sashal@kernel.org> (raw)
In-Reply-To: <20190814021047.14828-1-sashal@kernel.org>
From: Ilya Maximets <i.maximets@samsung.com>
[ Upstream commit decb705e01a5d325c9876b9674043cde4b54f0db ]
'channels.max_combined' initialized only on ioctl success and
errno is only valid on ioctl failure.
The code doesn't produce any runtime issues, but makes memory
sanitizers angry:
Conditional jump or move depends on uninitialised value(s)
at 0x55C056F: xsk_get_max_queues (xsk.c:336)
by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
by 0x55C0E57: xsk_socket__create (xsk.c:601)
Uninitialised value was created by a stack allocation
at 0x55C04CD: xsk_get_max_queues (xsk.c:318)
Additionally fixed warning on uninitialized bytes in ioctl arguments:
Syscall param ioctl(SIOCETHTOOL) points to uninitialised byte(s)
at 0x648D45B: ioctl (in /usr/lib64/libc-2.28.so)
by 0x55C0546: xsk_get_max_queues (xsk.c:330)
by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
by 0x55C0E57: xsk_socket__create (xsk.c:601)
Address 0x1ffefff378 is on thread 1's stack
in frame #1, created by xsk_get_max_queues (xsk.c:318)
Uninitialised value was created by a stack allocation
at 0x55C04CD: xsk_get_max_queues (xsk.c:318)
CC: Magnus Karlsson <magnus.karlsson@intel.com>
Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/lib/bpf/xsk.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index ca272c5b67f47..8e03b65830da0 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -327,15 +327,14 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk)
static int xsk_get_max_queues(struct xsk_socket *xsk)
{
- struct ethtool_channels channels;
- struct ifreq ifr;
+ struct ethtool_channels channels = { .cmd = ETHTOOL_GCHANNELS };
+ struct ifreq ifr = {};
int fd, err, ret;
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0)
return -errno;
- channels.cmd = ETHTOOL_GCHANNELS;
ifr.ifr_data = (void *)&channels;
strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);
ifr.ifr_name[IFNAMSIZ - 1] = '\0';
@@ -345,7 +344,7 @@ static int xsk_get_max_queues(struct xsk_socket *xsk)
goto out;
}
- if (channels.max_combined == 0 || errno == EOPNOTSUPP)
+ if (err || channels.max_combined == 0)
/* If the device says it has no channels, then all traffic
* is sent to a single stream, so max queues = 1.
*/
--
2.20.1
next prev parent reply other threads:[~2019-08-14 2:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190814021047.14828-1-sashal@kernel.org>
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 020/123] libbpf: sanitize VAR to conservative 1-byte INT Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 025/123] bpf: sockmap, sock_map_delete needs to use xchg Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 026/123] bpf: sockmap, synchronize_rcu before free'ing map Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 027/123] bpf: sockmap, only create entry if ulp is not already enabled Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 028/123] selftests/bpf: fix sendmsg6_prog on s390 Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 034/123] bpf: fix access to skb_shared_info->gso_segs Sasha Levin
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 035/123] selftests/bpf: add another gso_segs access Sasha Levin
2019-08-14 2:09 ` Sasha Levin [this message]
2019-08-14 2:09 ` [PATCH AUTOSEL 5.2 042/123] libbpf: silence GCC8 warning about string truncation Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190814021047.14828-36-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=andriin@fb.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=i.maximets@samsung.com \
--cc=linux-kernel@vger.kernel.org \
--cc=magnus.karlsson@intel.com \
--cc=netdev@vger.kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).