CVE-2023-52770: f2fs: split initial and dynamic conditions for extent_cache

Description

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

f2fs: split initial and dynamic conditions for extent_cache

Let's allocate the extent_cache tree without dynamic conditions to avoid a
missing condition causing a panic as below.

# create a file w/ a compressed flag
# disable the compression
# panic while updating extent_cache

F2FS-fs (dm-64): Swapfile: last extent is not aligned to section
F2FS-fs (dm-64): Swapfile (3) is not align to section: 1) creat(), 2) ioctl(F2FS_IOC_SET_PIN_FILE), 3) fallocate(2097152 * N)
Adding 124996k swap on ./swap-file. Priority:0 extents:2 across:17179494468k
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write out/common/include/linux/instrumented.h:101 [inline]
BUG: KASAN: null-ptr-deref in atomic_try_cmpxchg_acquire out/common/include/asm-generic/atomic-instrumented.h:705 [inline]
BUG: KASAN: null-ptr-deref in queued_write_lock out/common/include/asm-generic/qrwlock.h:92 [inline]
BUG: KASAN: null-ptr-deref in __raw_write_lock out/common/include/linux/rwlock_api_smp.h:211 [inline]
BUG: KASAN: null-ptr-deref in _raw_write_lock+0x5a/0x110 out/common/kernel/locking/spinlock.c:295
Write of size 4 at addr 0000000000000030 by task syz-executor154/3327

CPU: 0 PID: 3327 Comm: syz-executor154 Tainted: G O 5.10.185 #1
Hardware name: emulation qemu-x86/qemu-x86, BIOS 2023.01-21885-gb3cc1cd24d 01/01/2023
Call Trace:
__dump_stack out/common...

Classification

CVE ID: CVE-2023-52770

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/9de787139b0258a5dd1f498780c26d76b61d2958
https://git.kernel.org/stable/c/d83309e7e006cee8afca83523559017c824fbf7a
https://git.kernel.org/stable/c/f803982190f0265fd36cf84670aa6daefc2b0768

Timeline