resource leak in /net/tap.c

Hi,there might be a resource leak in function net_init_tap in /net/tap.c. 

 811         fd = monitor_fd_param(monitor_cur(), tap->fd, errp);
 812         if (fd == -1) {
 813             return -1;
 814         }
 815 
 816         ret = qemu_try_set_nonblock(fd);
 817         if (ret < 0) {
 818             error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
 819                              name, fd);
 820             return -1;
 821         }
 822 
 823         vnet_hdr = tap_probe_vnet_hdr(fd, errp);
 824         if (vnet_hdr < 0) {
 825             close(fd);
 826             return -1;
 827         }
 828 
 829         net_init_tap_one(tap, peer, "tap", name, NULL,
 830                          script, downscript,
 831                          vhostfdname, vnet_hdr, fd, &err);
 832         if (err) {
 833             error_propagate(errp, err);
 834             return -1;
 835         }

fd should be closed before return in line 820 and line 834, similar to the implementation in line 825.

hi yuanjungong,
You can send a patch to qemu-devel mailing list(https://wiki.qemu.org/MailingLists) to fix this memleak according to https://wiki.qemu.org/Contribute/SubmitAPatch.

Thanks.



Hi yuanjungong,

If you don't have time to submit a patch, can I submit a patch to fix it?

A patch has been submitted at https://lists.nongnu.org/archive/html/qemu-trivial/2020-11/msg00355.html

Hi Alex, 

Thanks for offering to help, but I submitted a patch to the maillist yesterday. Thank you again.

Hi -- the patch looks good to me, but it looks like you didn't send it to qemu-devel, only to qemu-trivial. Would you mind resending it to the right list, please? (You can cc qemu-trivial if you like, but all patches have to go to the main qemu-devel list, because systems like patchew https://patchew.org/QEMU/ and also many developers only read the main list.)


Fix now in master for 5.2 as commit f012bec8909820390936


Released with QEMU v5.2.0.