Vulnerability CVE-2021-47458

Vulnerability CVE-2021-47458

Published: 2024-05-22

Description:

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

ocfs2: mount fails with buffer overflow in strlen

Starting with kernel 5.11 built with CONFIG_FORTIFY_SOURCE mouting an
ocfs2 filesystem with either o2cb or pcmk cluster stack fails with the
trace below. Problem seems to be that strings for cluster stack and
cluster name are not guaranteed to be null terminated in the disk
representation, while strlcpy assumes that the source string is always
null terminated. This causes a read outside of the source string
triggering the buffer overflow detection.

detected buffer overflow in strlen
------------[ cut here ]------------
kernel BUG at lib/string.c:1149!
invalid opcode: 0000 [#1] SMP PTI
CPU: 1 PID: 910 Comm: mount.ocfs2 Not tainted 5.14.0-1-amd64 #1
Debian 5.14.6-2
RIP: 0010:fortify_panic+0xf/0x11
...
Call Trace:
ocfs2_initialize_super.isra.0.cold+0xc/0x18 [ocfs2]
ocfs2_fill_super+0x359/0x19b0 [ocfs2]
mount_bdev+0x185/0x1b0
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
path_mount+0x454/0xa20
__x64_sys_mount+0x103/0x140
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae

References:

https://git.kernel.org/stable/c/ac011cb3ff7a76b3e0e6e77158ee4ba2f929e1fb

https://git.kernel.org/stable/c/4b74ddcc22ee6455946e80a9c4808801f8f8561e

https://git.kernel.org/stable/c/232ed9752510de4436468b653d145565669c8498

https://git.kernel.org/stable/c/7623b1035ca2d17bde0f6a086ad6844a34648df1

https://git.kernel.org/stable/c/d3a83576378b4c904f711598dde2c5e881c4295c

https://git.kernel.org/stable/c/93be0eeea14cf39235e585c8f56df3b3859deaad

https://git.kernel.org/stable/c/0e677ea5b7396f715a76b6b0ef441430e4c4b57f

https://git.kernel.org/stable/c/b15fa9224e6e1239414525d8d556d824701849fc

Copyright 2026, cxsecurity.com