CVE-2021-20261

A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.

A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.

A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.

A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.

A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.

A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.

A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.

The SUSE Linux Enterprise 11 SP4 kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2021-3483: Fixed a use-after-free in nosy.c (bsc#1184393).
• CVE-2021-30002: Fixed a memory leak for large arguments in video_usercopy (bsc#1184120).
• CVE-2021-29650: Fixed an issue where the netfilter subsystem allowed attackers to cause a denial of service (bsc#1184208).
• CVE-2021-28972: Fixed a user-tolerable buffer overflow when writing a new device name to the driver from userspace, allowing userspace to write data to the kernel stack frame directly (bsc#1184198).
• CVE-2021-28950: Fixed an infinite loop because a retry loop continually finds the same bad inode (bsc#1184194).
• CVE-2021-27365: Fixed an issue where an unprivileged user can send a Netlink message that is associated with iSCSI, and has a length up to the maximum length of a Netlink message (bsc#1182715).
• CVE-2021-27364: Fixed an issue where an attacker could craft Netlink messages (bsc#1182717).
• CVE-2021-27363: Fixed a kernel pointer leak which could have been used to determine the address of the iscsi_transport structure (bsc#1182716).
• CVE-2021-20261: Fixed a race condition in the implementation of the floppy disk drive controller driver software (bsc#1183400).
• CVE-2020-36322: Fixed an issue in the FUSE filesystem implementation which could have caused a system crash (bsc#1184211).
• CVE-2020-35519: Fixed an out-of-bounds memory access was found in x25_bind (bsc#1183696).

The following non-security bugs were fixed:

• md: md.c: Return -ENODEV when mddev is NULL in rdev_attr_show (bsc#1056134, bsc#1180963).

Ben Harris discovered that the Linux kernel would strip extended privilege attributes of files when performing a failed unprivileged system call. A local attacker could use this to cause a denial of service. (CVE-2015-1350)

Andrey Konovalov discovered that the video4linux driver for Hauppauge HD PVR USB devices in the Linux kernel did not properly handle some error conditions. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-16644)

It was discovered that the timer stats implementation in the Linux kernel allowed the discovery of a real PID value while inside a PID namespace. A local attacker could use this to expose sensitive information. (CVE-2017-5967)

Wen Xu discovered that the xfs file system implementation in the Linux kernel did not properly validate the number of extents in an inode. An attacker could use this to construct a malicious xfs image that, when mounted, could cause a denial of service (system crash). (CVE-2018-13095)

It was discovered that the Fujitsu ES network device driver for the Linux kernel did not properly check for errors in some situations, leading to a NULL pointer dereference. A local attacker could use this to cause a denial of service. (CVE-2019-16231)

It was discovered that the Marvell 8xxx Libertas WLAN device driver in the Linux kernel did not properly check for errors in certain situations, leading to a NULL pointer dereference. A local attacker could possibly use this to cause a denial of service. (CVE-2019-16232)

It was discovered that the ADIS16400 IIO IMU Driver for the Linux kernel did not properly deallocate memory in certain error conditions. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2019-19061)

It was discovered that a race condition existed in the floppy device driver in the Linux kernel. An attacker with access to the floppy device could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-20261)

Olivier Benjamin, Norbert Manthey, Martin Mazein, and Jan H. Schönherr discovered that the Xen paravirtualization backend in the Linux kernel did not properly propagate errors to frontend drivers in some situations. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26930)

Jan Beulich discovered that multiple Xen backends in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26931)

Jan Beulich discovered that the Xen netback backend in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-28038)