Affected: Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

tun: Fix memory leak for detached NAPI queue.

syzkaller reported [0] memory leaks of sk and skb related to the TUN device with no repro, but we can reproduce it easily with:

struct ifreq ifr = {} int fd_tun, fd_tmp; char buf[4] = {};

fd_tun = openat(AT_FDCWD, "/dev/net/tun", O_WRONLY, 0); ifr.ifr_flags = IFF_TUN | IFF_NAPI | IFF_MULTI_QUEUE; ioctl(fd_tun, TUNSETIFF, &ifr);

ifr.ifr_flags = IFF_DETACH_QUEUE; ioctl(fd_tun, TUNSETQUEUE, &ifr);

fd_tmp = socket(AF_PACKET, SOCK_PACKET, 0); ifr.ifr_flags = IFF_UP; ioctl(fd_tmp, SIOCSIFFLAGS, &ifr);

write(fd_tun, buf, sizeof(buf)); close(fd_tun);

If we enable NAPI and multi-queue on a TUN device, we can put skb into tfile->sk.sk_write_queue after the queue is detached. We should prevent it by checking tfile->detached before queuing skb.

Note this must be done under tfile->sk.sk_write_queue.lock because write() and ioctl(IFF_DETACH_QUEUE) can run concurrently. Otherwise, there would be a small race window:

write() ioctl(IFF_DETACH_QUEUE) `- tun_get_user `- __tun_detach |- if (tfile->detached) |- tun_disable_queue | `-> false | `- tfile->detached = tun | `- tun_queue_purge |- spin_lock_bh(&queue->lock) `- __skb_queue_tail(queue, skb)

Another solution is to call tun_queue_purge() when c…

In the Linux kernel, the following vulnerability has been resolved:

tun: Fix memory leak for detached NAPI queue.

syzkaller reported [0] memory leaks of sk and skb related to the TUN device with no repro, but we can reproduce it easily with:

struct ifreq ifr = {} int fd_tun, fd_tmp; char buf[4] = {};

fd_tun = openat(AT_FDCWD, "/dev/net/tun", O_WRONLY, 0); ifr.ifr_flags = IFF_TUN | IFF_NAPI | IFF_MULTI_QUEUE; ioctl(fd_tun, TUNSETIFF, &ifr);

ifr.ifr_flags = IFF_DETACH_QUEUE; ioctl(fd_tun, TUNSETQUEUE, &ifr);

fd_tmp = socket(AF_PACKET, SOCK_PACKET, 0); ifr.ifr_flags = IFF_UP; ioctl(fd_tmp, SIOCSIFFLAGS, &ifr);

write(fd_tun, buf, sizeof(buf)); close(fd_tun);

If we enable NAPI and multi-queue on a TUN device, we can put skb into tfile->sk.sk_write_queue after the queue is detached. We should prevent it by checking tfile->detached before queuing skb.

Note this must be done under tfile->sk.sk_write_queue.lock because write() and ioctl(IFF_DETACH_QUEUE) can run concurrently. Otherwise, there would be a small race window:

write() ioctl(IFF_DETACH_QUEUE) `- tun_get_user `- __tun_detach |- if (tfile->detached) |- tun_disable_queue | `-> false | `- tfile->detached = tun | `- tun_queue_purge |- spin_lock_bh(&queue->lock) `- __skb_queue_tail(queue, skb)

Another solution is to call tun_queue_purge() when c…

Security update for the Linux Kernel

Affected: Ubuntu:Pro:14.04:LTS: linux, Ubuntu:Pro:14.04:LTS: linux-aws, Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:14.04:LTS: linux-lts-xenial, Ubuntu:Pro:16.04:LTS: linux, Ubuntu:Pro:16.04:LTS: linux-aws, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe and 170 more

In the Linux kernel, the following vulnerability has been resolved: tun: Fix memory leak for detached NAPI queue. syzkaller reported [0] memory leaks of sk and skb related to the TUN device with no repro, but we can reproduce it easily with: struct ifreq ifr = {} int fd_tun, fd_tmp; char buf[4] = {}; fd_tun = openat(AT_FDCWD, "/dev/net/tun", O_WRONLY, 0); ifr.ifr_flags = IFF_TUN | IFF_NAPI | IFF_MULTI_QUEUE; ioctl(fd_tun, TUNSETIFF, &ifr); ifr.ifr_flags = IFF_DETACH_QUEUE; ioctl(fd_tun, TUNSETQUEUE, &ifr); fd_tmp = socket(AF_PACKET, SOCK_PACKET, 0); ifr.ifr_flags = IFF_UP; ioctl(fd_tmp, SIOCSIFFLAGS, &ifr); write(fd_tun, buf, sizeof(buf)); close(fd_tun); If we enable NAPI and multi-queue on a TUN device, we can put skb into tfile->sk.sk_write_queue after the queue is detached. We should prevent it by checking tfile->detached before queuing skb. Note this must be done under tfile->sk.sk_write_queue.lock because write() and ioctl(IFF_DETACH_QUEUE) can run concurrently. Otherwise, there would be a small race window: write() ioctl(IFF_DETACH_QUEUE) `- tun_get_user `- __tun_detach |- if (tfile->detached) |- tun_disable_queue | `-> false | `- tfile->detached = tun | `- tun_queue_purge |- spin_lock_bh(&queue->lock) `- __skb_queue_tail(queue, skb) Another solution is to call tun_queue_purge() when closing and…

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen und andere nicht näher spezifizierte Angriffe durchzuführen.