CVE-2022-48631

Medium

In the Linux kernel, the following vulnerability has been resolved: ext4: fix bug in extents parsing when eh_entries == 0 and eh_depth > 0 When walking through an inode extents, the ext4_ext_binsearch_idx() function assumes that the extent header has been previously validated. However, there are no checks that verify that the number of entries (eh->eh_entries) is non-zero when depth is > 0. And this will lead to problems because the EXT_FIRST_INDEX() and EXT_LAST_INDEX() will return garbage and result in this: [ 135.245946] ------------[ cut here ]------------ [ 135.247579] kernel BUG at fs/ext4/extents.c:2258! [ 135.249045] invalid opcode: 0000 [#1] PREEMPT SMP [ 135.250320] CPU: 2 PID: 238 Comm: tmp118 Not tainted 5.19.0-rc8+ #4 [ 135.252067] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014 [ 135.255065] RIP: 0010:ext4_ext_map_blocks+0xc20/0xcb0 [ 135.256475] Code: [ 135.261433] RSP: 0018:ffffc900005939f8 EFLAGS: 00010246 [ 135.262847] RAX: 0000000000000024 RBX: ffffc90000593b70 RCX: 0000000000000023 [ 135.264765] RDX: ffff8880038e5f10 RSI: 0000000000000003 RDI: ffff8880046e922c [ 135.266670] RBP: ffff8880046e9348 R08: 0000000000000001 R09: ffff888002ca580c [ 135.268576] R10: 0000000000002602 R11: 0000000000000000 R12: 0000000000000024 [ 135.270477] R13: 0000000000000000 R14: 0000000000000024 R15: 0000000000000000 [ 135.272394] FS: 00007fdabdc56740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000 [ 135.274510] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 135.276075] CR2: 00007ffc26bd4f00 CR3: 0000000006261004 CR4: 0000000000170ea0 [ 135.277952] Call Trace: [ 135.278635] <TASK> [ 135.279247] ? preempt_count_add+0x6d/0xa0 [ 135.280358] ? percpu_counter_add_batch+0x55/0xb0 [ 135.281612] ? _raw_read_unlock+0x18/0x30 [ 135.282704] ext4_map_blocks+0x294/0x5a0 [ 135.283745] ? xa_load+0x6f/0xa0 [ 135.284562] ext4_mpage_readpages+0x3d6/0x770 [ 135.285646] read_pages+0x67/0x1d0 [ 135.286492] ? folio_add_lru+0x51/0x80 [ 135.287441] page_cache_ra_unbounded+0x124/0x170 [ 135.288510] filemap_get_pages+0x23d/0x5a0 [ 135.289457] ? path_openat+0xa72/0xdd0 [ 135.290332] filemap_read+0xbf/0x300 [ 135.291158] ? _raw_spin_lock_irqsave+0x17/0x40 [ 135.292192] new_sync_read+0x103/0x170 [ 135.293014] vfs_read+0x15d/0x180 [ 135.293745] ksys_read+0xa1/0xe0 [ 135.294461] do_syscall_64+0x3c/0x80 [ 135.295284] entry_SYSCALL_64_after_hwframe+0x46/0xb0 This patch simply adds an extra check in __ext4_ext_check(), verifying that eh_entries is not 0 when eh_depth is > 0.

Package Linux Kernel
Published 2024-04-28
Last modified 2025-09-19
CVSS version 3.1
Patch available
Awaiting data

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

The following references provide additional information about CVE-2022-48631 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2022-48631?

    CVE-2022-48631 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . CVE-2022-48631 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2022-48631?

    CVE-2022-48631 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2022-48631?

    No patch is currently available for CVE-2022-48631. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

  • Is CVE-2022-48631 actively exploited?

    No — CVE-2022-48631 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.