A kernel security update has been released for Fedora 34.

SECURITY: Fedora 34 Update: kernel-5.11.20-300.fc34

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Fedora Update Notification
FEDORA-2021-286375de1e
2021-05-16 02:01:05.994666
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Name : kernel
Product : Fedora 34
Version : 5.11.20
Release : 300.fc34
URL :   https://www.kernel.org/
Summary : The Linux kernel
Description :
The kernel meta package

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Update Information:

The 5.11.20 stable kernel update contains a number of important fixes across the
tree.
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ChangeLog:

* Wed May 12 2021 Justin M. Forbes [5.11.20-0]
- io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers (Thadeu Lima de Souza Cascardo)
- bpf: Prevent writable memory-mapping of read-only ringbuf pages (Andrii Nakryiko)
- bpf, ringbuf: Deny reserve of buffers larger than ringbuf (Thadeu Lima de Souza Cascardo)
- bpf: Fix alu32 const subreg bound tracking on bitwise operations (Daniel Borkmann)
- net/nfc: fix use-after-free llcp_sock_bind/connect (Or Cohen)
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References:

[ 1 ] Bug #1959514 - CVE-2021-23134 kernel: use-after-free in nfc sockets
  https://bugzilla.redhat.com/show_bug.cgi?id=1959514
[ 2 ] Bug #1959556 - CVE-2021-3490 kernel: Linux kernel eBPF bitwise ops ALU32 bounds tracking
  https://bugzilla.redhat.com/show_bug.cgi?id=1959556
[ 3 ] Bug #1959559 - CVE-2021-3489 kernel: Linux kernel eBPF RINGBUF map oversized allocation
  https://bugzilla.redhat.com/show_bug.cgi?id=1959559
[ 4 ] Bug #1959565 - CVE-2021-3491 kernel: Linux kernel io_uring PROVIDE_BUFFERS MAX_RW_COUNT bypass
  https://bugzilla.redhat.com/show_bug.cgi?id=1959565
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This update can be installed with the "dnf" update program. Use
su -c 'dnf upgrade --advisory FEDORA-2021-286375de1e' at the command
line. For more information, refer to the dnf documentation available at
  http://dnf.readthedocs.io/en/latest/command_ref.html#upgrade-command-label

All packages are signed with the Fedora Project GPG key. More details on the
GPG keys used by the Fedora Project can be found at
  https://fedoraproject.org/keys