| Message ID | 20220106182851.3583896-1-venture@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | net: Fix uninitialized data usage | expand |
On 6/1/22 19:28, Patrick Venture wrote: > From: Peter Foley <pefoley@google.com> > > 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 <wuhaotsh@google.com> > Reviewed-by: Patrick Venture <venture@google.com> > Signed-off-by: Peter Foley <pefoley@google.com> > --- > net/tap-linux.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/net/tap-linux.c b/net/tap-linux.c > index 9584769740..5e70b93037 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)); Or: struct ifreq ifr = { }; Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > > if (ioctl(fd, TUNGETIFF, &ifr) != 0) { > /* TUNGETIFF is available since kernel v2.6.27 */
Yeah, but this same pattern is used elsewhere in the file, so I went with being consistent. On Thu, Jan 6, 2022, 2:44 PM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: > On 6/1/22 19:28, Patrick Venture wrote: > > From: Peter Foley <pefoley@google.com> > > > > 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 <wuhaotsh@google.com> > > Reviewed-by: Patrick Venture <venture@google.com> > > Signed-off-by: Peter Foley <pefoley@google.com> > > --- > > net/tap-linux.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/net/tap-linux.c b/net/tap-linux.c > > index 9584769740..5e70b93037 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)); > > Or: > > struct ifreq ifr = { }; > > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > > > > > if (ioctl(fd, TUNGETIFF, &ifr) != 0) { > > /* TUNGETIFF is available since kernel v2.6.27 */ > >
On Fri, Jan 7, 2022 at 3:44 AM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: > > On 6/1/22 19:28, Patrick Venture wrote: > > From: Peter Foley <pefoley@google.com> > > > > 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 <wuhaotsh@google.com> > > Reviewed-by: Patrick Venture <venture@google.com> > > Signed-off-by: Peter Foley <pefoley@google.com> > > --- > > net/tap-linux.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/net/tap-linux.c b/net/tap-linux.c > > index 9584769740..5e70b93037 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)); > > Or: > > struct ifreq ifr = { }; > > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Applied. Thanks > > > > > if (ioctl(fd, TUNGETIFF, &ifr) != 0) { > > /* TUNGETIFF is available since kernel v2.6.27 */ >
diff --git a/net/tap-linux.c b/net/tap-linux.c index 9584769740..5e70b93037 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 */