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authorIlya Maximets <i.maximets@samsung.com>2019-07-23 15:08:10 +0300
committerAlexei Starovoitov <ast@kernel.org>2019-07-23 15:14:35 -0700
commitdecb705e01a5d325c9876b9674043cde4b54f0db (patch)
treedfe665d20a2f6df6c47403f95faa527a771c656d /tools/lib
parent7c8b87f012614697596b78841c0d0b1520b1f88a (diff)
libbpf: fix using uninitialized ioctl results
'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>
Diffstat (limited to 'tools/lib')
-rw-r--r--tools/lib/bpf/xsk.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index 5007b5d4fd2c..e02025bbe36d 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -317,15 +317,14 @@ 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';
@@ -335,7 +334,7 @@ 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.
*/