Linux Kernel up to 5.10.109/5.15.32/5.16.18/5.17.1 fs/f2fs/segment.c block_count[] array index

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 5.10.109/5.15.32/5.16.18/5.17.1. The impacted element is an unknown function of the file fs/f2fs/segment.c. The manipulation of the argument block_count[] leads to array index. This vulnerability is referenced as CVE-2022-49170. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 5.10.109/5.15.32/5.16.18/5.17.1. This issue affects some unknown functionality of the file fs/f2fs/segment.c. The manipulation of the argument block_count[] with an unknown input leads to a array index vulnerability. Using CWE to declare the problem leads to CWE-129. The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on curseg->alloc_type As Wenqing Liu reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215657 - Overview UBSAN: array-index-out-of-bounds in fs/f2fs/segment.c:3460:2 when mount and operate a corrupted image - Reproduce tested on kernel 5.17-rc4, 5.17-rc6 1. mkdir test_crash 2. cd test_crash 3. unzip tmp2.zip 4. mkdir mnt 5. ./single_test.sh f2fs 2 - Kernel dump [ 46.434454] loop0: detected capacity change from 0 to 131072 [ 46.529839] F2FS-fs (loop0): Mounted with checkpoint version = 7548c2d9 [ 46.738319] ================================================================================ [ 46.738412] UBSAN: array-index-out-of-bounds in fs/f2fs/segment.c:3460:2 [ 46.738475] index 231 is out of range for type 'unsigned int [2]' [ 46.738539] CPU: 2 PID: 939 Comm: umount Not tainted 5.17.0-rc6 #1 [ 46.738547] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014 [ 46.738551] Call Trace: [ 46.738556] [ 46.738563] dump_stack_lvl+0x47/0x5c [ 46.738581] ubsan_epilogue+0x5/0x50 [ 46.738592] __ubsan_handle_out_of_bounds+0x68/0x80 [ 46.738604] f2fs_allocate_data_block+0xdff/0xe60 [f2fs] [ 46.738819] do_write_page+0xef/0x210 [f2fs] [ 46.738934] f2fs_do_write_node_page+0x3f/0x80 [f2fs] [ 46.739038] __write_node_page+0x2b7/0x920 [f2fs] [ 46.739162] f2fs_sync_node_pages+0x943/0xb00 [f2fs] [ 46.739293] f2fs_write_checkpoint+0x7bb/0x1030 [f2fs] [ 46.739405] kill_f2fs_super+0x125/0x150 [f2fs] [ 46.739507] deactivate_locked_super+0x60/0xc0 [ 46.739517] deactivate_super+0x70/0xb0 [ 46.739524] cleanup_mnt+0x11a/0x200 [ 46.739532] __cleanup_mnt+0x16/0x20 [ 46.739538] task_work_run+0x67/0xa0 [ 46.739547] exit_to_user_mode_prepare+0x18c/0x1a0 [ 46.739559] syscall_exit_to_user_mode+0x26/0x40 [ 46.739568] do_syscall_64+0x46/0xb0 [ 46.739584] entry_SYSCALL_64_after_hwframe+0x44/0xae The root cause is we missed to do sanity check on curseg->alloc_type, result in out-of-bound accessing on sbi->block_count[] array, fix it.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2022-49170 since 02/26/2025. The exploitation is known to be difficult. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/26/2025).

Upgrading to version 5.10.110, 5.15.33, 5.16.19 or 5.17.2 eliminates this vulnerability. Applying the patch 498b7088db71f9707359448cd6800bbb1882f4c3/f68caedf264a95c0b02dfd0d9f92ac2637d5848a/0748a0f7dcb9d9dddc80302d73ebcecef6782ef0/c12765e3f129b144421c80d3383df885f85ee290/f41ee8b91c00770d718be2ff4852a80017ae9ab3 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.109
• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.15.26
• 5.15.27
• 5.15.28
• 5.15.29
• 5.15.30
• 5.15.31
• 5.15.32
• 5.16.0
• 5.16.1
• 5.16.2
• 5.16.3
• 5.16.4
• 5.16.5
• 5.16.6
• 5.16.7
• 5.16.8
• 5.16.9
• 5.16.10
• 5.16.11
• 5.16.12
• 5.16.13
• 5.16.14
• 5.16.15
• 5.16.16
• 5.16.17
• 5.16.18
• 5.17.0
• 5.17.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion