Subject: CVE-2022-48877: f2fs: let's avoid panic if extent_tree is not created

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

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

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

f2fs: let's avoid panic if extent_tree is not created

This patch avoids the below panic.

pc : __lookup_extent_tree+0xd8/0x760
lr : f2fs_do_write_data_page+0x104/0x87c
sp : ffffffc010cbb3c0
x29: ffffffc010cbb3e0 x28: 0000000000000000
x27: ffffff8803e7f020 x26: ffffff8803e7ed40
x25: ffffff8803e7f020 x24: ffffffc010cbb460
x23: ffffffc010cbb480 x22: 0000000000000000
x21: 0000000000000000 x20: ffffffff22e90900
x19: 0000000000000000 x18: ffffffc010c5d080
x17: 0000000000000000 x16: 0000000000000020
x15: ffffffdb1acdbb88 x14: ffffff888759e2b0
x13: 0000000000000000 x12: ffffff802da49000
x11: 000000000a001200 x10: ffffff8803e7ed40
x9 : ffffff8023195800 x8 : ffffff802da49078
x7 : 0000000000000001 x6 : 0000000000000000
x5 : 0000000000000006 x4 : ffffffc010cbba28
x3 : 0000000000000000 x2 : ffffffc010cbb480
x1 : 0000000000000000 x0 : ffffff8803e7ed40
Call trace:
 __lookup_extent_tree+0xd8/0x760
 f2fs_do_write_data_page+0x104/0x87c
 f2fs_write_single_data_page+0x420/0xb60
 f2fs_write_cache_pages+0x418/0xb1c
 __f2fs_write_data_pages+0x428/0x58c
 f2fs_write_data_pages+0x30/0x40
 do_writepages+0x88/0x190
 __writeback_single_inode+0x48/0x448
 writeback_sb_inodes+0x468/0x9e8
 __writeback_inodes_wb+0xb8/0x2a4
 wb_writeback+0x33c/0x740
 wb_do_writeback+0x2b4/0x400
 wb_workfn+0xe4/0x34c
 process_one_work+0x24c/0x5bc
 worker_thread+0x3e8/0xa50
 kthread+0x150/0x1b4

The Linux kernel CVE team has assigned CVE-2022-48877 to this issue.

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

	Fixed in 4.14.304 with commit dd83a9763e29
	Fixed in 4.19.271 with commit ff85a1dbd90d
	Fixed in 5.4.230 with commit 557e85ff9afe
	Fixed in 5.10.165 with commit 72009139a661
	Fixed in 5.15.90 with commit 2c129e868992
	Fixed in 6.1.8 with commit 1c38cdc747f0
	Fixed in 6.2 with commit df9d44b645b8

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-2022-48877
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/f2fs/extent_cache.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/dd83a9763e29ed7a21c8a43f7a62cd0a6bf74692
	https://git.kernel.org/stable/c/ff85a1dbd90d29f73033177ff8d8de4a27d9721c
	https://git.kernel.org/stable/c/557e85ff9afef6d45020b6f09357111d38033c31
	https://git.kernel.org/stable/c/72009139a661ade5cb1da4239734ed02fa1cfff0
	https://git.kernel.org/stable/c/2c129e868992621a739bdd57a5bffa3985ef1b91
	https://git.kernel.org/stable/c/1c38cdc747f00daf7394535eae5afc4c503c59bb
	https://git.kernel.org/stable/c/df9d44b645b83fffccfb4e28c1f93376585fdec8