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CVE-2022-50314

In the Linux kernel, the following vulnerability has been resolved: nbd: Fix hung when signal interrupts nbd_start_device_ioctl() syzbot reported hung task [1].

Impact

In the Linux kernel, the following vulnerability has been resolved: nbd: Fix hung when signal interrupts nbd_start_device_ioctl() syzbot reported hung task [1]. The following program is a simplified version of the reproducer: int main(void) { int sv[2], fd; if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) < 0) return 1; if ((fd = open("/dev/nbd0", 0)) < 0) return 1; if (ioctl(fd, NBD_SET_SIZE_BLOCKS, 0x81) < 0) return 1; if (ioctl(fd, NBD_SET_SOCK, sv[0]) < 0) return 1; if (ioctl(fd, NBD_DO_IT) < 0) return 1; return 0; } When signal interrupt nbd_start_device_ioctl() waiting the condition atomic_read(&config->recv_threads) == 0, the task can hung because it waits the completion of the inflight IOs. This patch fixes the issue by clearing queue, not just shutdown, when signal interrupt nbd_start_device_ioctl().

Affected products

VendorProductAffected versions
LinuxLinux Kernel
before 4.14.296
from 4.15 before 4.19.262
from 4.20 before 5.4.220
from 5.5 before 5.10.150
from 5.11 before 5.15.75
from 5.16 before 5.19.17

References