From e29919c93d19118610d64de9deb9c223024c0bc6 Mon Sep 17 00:00:00 2001 From: Peter Foley Date: Fri, 14 Jan 2022 13:08:59 +0800 Subject: [PATCH] net: Fix uninitialized data usage MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit e.g. 1109 15:16:20.151506 Uninitialized bytes in ioctl_common_pre at offset 0 inside [0x7ffc516af9b8, 4) 1109 15:16:20.151659 ==588974==WARNING: MemorySanitizer: use-of-uninitialized-value 1109 15:16:20.312923 #0 0x5639b88acb21 in tap_probe_vnet_hdr_len third_party/qemu/net/tap-linux.c:183:9 1109 15:16:20.312952 #1 0x5639b88afd66 in net_tap_fd_init third_party/qemu/net/tap.c:409:9 1109 15:16:20.312954 #2 0x5639b88b2d1b in net_init_tap_one third_party/qemu/net/tap.c:681:19 1109 15:16:20.312956 #3 0x5639b88b16a8 in net_init_tap third_party/qemu/net/tap.c:912:13 1109 15:16:20.312957 #4 0x5639b8890175 in net_client_init1 third_party/qemu/net/net.c:1110:9 1109 15:16:20.312958 #5 0x5639b888f912 in net_client_init third_party/qemu/net/net.c:1208:15 1109 15:16:20.312960 #6 0x5639b8894aa5 in net_param_nic third_party/qemu/net/net.c:1588:11 1109 15:16:20.312961 #7 0x5639b900cd18 in qemu_opts_foreach third_party/qemu/util/qemu-option.c:1135:14 1109 15:16:20.312962 #8 0x5639b889393c in net_init_clients third_party/qemu/net/net.c:1612:9 1109 15:16:20.312964 #9 0x5639b717aaf3 in qemu_create_late_backends third_party/qemu/softmmu/vl.c:1962:5 1109 15:16:20.312965 #10 0x5639b717aaf3 in qemu_init third_party/qemu/softmmu/vl.c:3694:5 1109 15:16:20.312967 #11 0x5639b71083b8 in main third_party/qemu/softmmu/main.c:49:5 1109 15:16:20.312968 #12 0x7f464de1d8d2 in __libc_start_main (/usr/grte/v5/lib64/libc.so.6+0x628d2) 1109 15:16:20.312969 #13 0x5639b6bbd389 in _start /usr/grte/v5/debug-src/src/csu/../sysdeps/x86_64/start.S:120 1109 15:16:20.312970 1109 15:16:20.312975 Uninitialized value was stored to memory at 1109 15:16:20.313393 #0 0x5639b88acbee in tap_probe_vnet_hdr_len third_party/qemu/net/tap-linux.c 1109 15:16:20.313396 #1 0x5639b88afd66 in net_tap_fd_init third_party/qemu/net/tap.c:409:9 1109 15:16:20.313398 #2 0x5639b88b2d1b in net_init_tap_one third_party/qemu/net/tap.c:681:19 1109 15:16:20.313399 #3 0x5639b88b16a8 in net_init_tap third_party/qemu/net/tap.c:912:13 1109 15:16:20.313400 #4 0x5639b8890175 in net_client_init1 third_party/qemu/net/net.c:1110:9 1109 15:16:20.313401 #5 0x5639b888f912 in net_client_init third_party/qemu/net/net.c:1208:15 1109 15:16:20.313403 #6 0x5639b8894aa5 in net_param_nic third_party/qemu/net/net.c:1588:11 1109 15:16:20.313404 #7 0x5639b900cd18 in qemu_opts_foreach third_party/qemu/util/qemu-option.c:1135:14 1109 15:16:20.313405 #8 0x5639b889393c in net_init_clients third_party/qemu/net/net.c:1612:9 1109 15:16:20.313407 #9 0x5639b717aaf3 in qemu_create_late_backends third_party/qemu/softmmu/vl.c:1962:5 1109 15:16:20.313408 #10 0x5639b717aaf3 in qemu_init third_party/qemu/softmmu/vl.c:3694:5 1109 15:16:20.313409 #11 0x5639b71083b8 in main third_party/qemu/softmmu/main.c:49:5 1109 15:16:20.313410 #12 0x7f464de1d8d2 in __libc_start_main (/usr/grte/v5/lib64/libc.so.6+0x628d2) 1109 15:16:20.313412 #13 0x5639b6bbd389 in _start /usr/grte/v5/debug-src/src/csu/../sysdeps/x86_64/start.S:120 1109 15:16:20.313413 1109 15:16:20.313417 Uninitialized value was stored to memory at 1109 15:16:20.313791 #0 0x5639b88affbd in net_tap_fd_init third_party/qemu/net/tap.c:400:26 1109 15:16:20.313826 #1 0x5639b88b2d1b in net_init_tap_one third_party/qemu/net/tap.c:681:19 1109 15:16:20.313829 #2 0x5639b88b16a8 in net_init_tap third_party/qemu/net/tap.c:912:13 1109 15:16:20.313831 #3 0x5639b8890175 in net_client_init1 third_party/qemu/net/net.c:1110:9 1109 15:16:20.313836 #4 0x5639b888f912 in net_client_init third_party/qemu/net/net.c:1208:15 1109 15:16:20.313838 #5 0x5639b8894aa5 in net_param_nic third_party/qemu/net/net.c:1588:11 1109 15:16:20.313839 #6 0x5639b900cd18 in qemu_opts_foreach third_party/qemu/util/qemu-option.c:1135:14 1109 15:16:20.313841 #7 0x5639b889393c in net_init_clients third_party/qemu/net/net.c:1612:9 1109 15:16:20.313843 #8 0x5639b717aaf3 in qemu_create_late_backends third_party/qemu/softmmu/vl.c:1962:5 1109 15:16:20.313844 #9 0x5639b717aaf3 in qemu_init third_party/qemu/softmmu/vl.c:3694:5 1109 15:16:20.313845 #10 0x5639b71083b8 in main third_party/qemu/softmmu/main.c:49:5 1109 15:16:20.313846 #11 0x7f464de1d8d2 in __libc_start_main (/usr/grte/v5/lib64/libc.so.6+0x628d2) 1109 15:16:20.313847 #12 0x5639b6bbd389 in _start /usr/grte/v5/debug-src/src/csu/../sysdeps/x86_64/start.S:120 1109 15:16:20.313849 1109 15:16:20.313851 Uninitialized value was created by an allocation of 'ifr' in the stack frame of function 'tap_probe_vnet_hdr' 1109 15:16:20.313855 #0 0x5639b88ac680 in tap_probe_vnet_hdr third_party/qemu/net/tap-linux.c:151 1109 15:16:20.313856 1109 15:16:20.313878 SUMMARY: MemorySanitizer: use-of-uninitialized-value third_party/qemu/net/tap-linux.c:183:9 in tap_probe_vnet_hdr_len Fixes: dc69004c7d8 ("net: move tap_probe_vnet_hdr() to tap-linux.c") Reviewed-by: Hao Wu Reviewed-by: Patrick Venture Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Peter Foley Signed-off-by: Jason Wang --- net/tap-linux.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/tap-linux.c b/net/tap-linux.c index 958476974010..5e70b9303710 100644 --- a/net/tap-linux.c +++ b/net/tap-linux.c @@ -150,6 +150,7 @@ void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp) int tap_probe_vnet_hdr(int fd, Error **errp) { struct ifreq ifr; + memset(&ifr, 0, sizeof(ifr)); if (ioctl(fd, TUNGETIFF, &ifr) != 0) { /* TUNGETIFF is available since kernel v2.6.27 */