Subject: CVE-2023-52810: fs/jfs: Add check for negative db_l2nbperpage

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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

fs/jfs: Add check for negative db_l2nbperpage

l2nbperpage is log2(number of blks per page), and the minimum legal
value should be 0, not negative.

In the case of l2nbperpage being negative, an error will occur
when subsequently used as shift exponent.

Syzbot reported this bug:

UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:799:12
shift exponent -16777216 is negative

The Linux kernel CVE team has assigned CVE-2023-52810 to this issue.

Affected and fixed versions
===========================

	Fixed in 4.14.331 with commit cc61fcf7d1c9
	Fixed in 4.19.300 with commit 8f2964df6bfc
	Fixed in 5.4.262 with commit a81a56b4cbe3
	Fixed in 5.10.202 with commit 524b4f203afc
	Fixed in 5.15.140 with commit 5f148b16972e
	Fixed in 6.1.64 with commit 0cb567e72733
	Fixed in 6.5.13 with commit 491085258185
	Fixed in 6.6.3 with commit 1a7c53fdea1d
	Fixed in 6.7 with commit 525b861a0081

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2023-52810
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	fs/jfs/jfs_dmap.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/cc61fcf7d1c99f148fe8ddfb5c6ed0bb75861f01
	https://git.kernel.org/stable/c/8f2964df6bfce9d92d81ca552010b8677af8d9dc
	https://git.kernel.org/stable/c/a81a56b4cbe3142cc99f6b98e8f9b3a631c768e1
	https://git.kernel.org/stable/c/524b4f203afcf87accfe387e846f33f916f0c907
	https://git.kernel.org/stable/c/5f148b16972e5f4592629b244d5109b15135f53f
	https://git.kernel.org/stable/c/0cb567e727339a192f9fd0db00781d73a91d15a6
	https://git.kernel.org/stable/c/491085258185ffc4fb91555b0dba895fe7656a45
	https://git.kernel.org/stable/c/1a7c53fdea1d189087544d9a606d249e93c4934b
	https://git.kernel.org/stable/c/525b861a008143048535011f3816d407940f4bfa