Subject: CVE-2024-50006: ext4: fix i_data_sem unlock order in ext4_ind_migrate()

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

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

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

ext4: fix i_data_sem unlock order in ext4_ind_migrate()

Fuzzing reports a possible deadlock in jbd2_log_wait_commit.

This issue is triggered when an EXT4_IOC_MIGRATE ioctl is set to require
synchronous updates because the file descriptor is opened with O_SYNC.
This can lead to the jbd2_journal_stop() function calling
jbd2_might_wait_for_commit(), potentially causing a deadlock if the
EXT4_IOC_MIGRATE call races with a write(2) system call.

This problem only arises when CONFIG_PROVE_LOCKING is enabled. In this
case, the jbd2_might_wait_for_commit macro locks jbd2_handle in the
jbd2_journal_stop function while i_data_sem is locked. This triggers
lockdep because the jbd2_journal_start function might also lock the same
jbd2_handle simultaneously.

Found by Linux Verification Center (linuxtesting.org) with syzkaller.

Rule: add

The Linux kernel CVE team has assigned CVE-2024-50006 to this issue.

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

	Fixed in 5.10.227 with commit 53b1999cfd2c
	Fixed in 5.15.168 with commit ef05572da0c0
	Fixed in 6.1.113 with commit 9fedf51ab8cf
	Fixed in 6.6.55 with commit d43776b90765
	Fixed in 6.10.14 with commit 6252cb6bde7f
	Fixed in 6.11.3 with commit d58a00e981d3
	Fixed in 6.12-rc1 with commit cc749e61c011

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-2024-50006
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/ext4/migrate.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/53b1999cfd2c7addf2e581a32865fe8835467b44
	https://git.kernel.org/stable/c/ef05572da0c0eb89614ed01cc17d3c882bdbd1ff
	https://git.kernel.org/stable/c/9fedf51ab8cf7b69bff08f37fe0989fec7f5d870
	https://git.kernel.org/stable/c/d43776b907659affef1de888525847d64b244194
	https://git.kernel.org/stable/c/6252cb6bde7fc76cb8dcb49d1def7c326b190820
	https://git.kernel.org/stable/c/d58a00e981d3118b91d503da263e640b7cde6729
	https://git.kernel.org/stable/c/cc749e61c011c255d81b192a822db650c68b313f