CVE-2022-49255: Vulnerability in Linux Linux

Severity: highType: vulnerabilityCVE-2022-49255

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix missing free nid in f2fs_handle_failed_inode This patch fixes xfstests/generic/475 failure. [ 293.680694] F2FS-fs (dm-1): May loss orphan inode, run fsck to fix. [ 293.685358] Buffer I/O error on dev dm-1, logical block 8388592, async page read [ 293.691527] Buffer I/O error on dev dm-1, logical block 8388592, async page read [ 293.691764] sh (7615): drop_caches: 3 [ 293.691819] sh (7616): drop_caches: 3 [ 293.694017] Buffer I/O error on dev dm-1, logical block 1, async page read [ 293.695659] sh (7618): drop_caches: 3 [ 293.696979] sh (7617): drop_caches: 3 [ 293.700290] sh (7623): drop_caches: 3 [ 293.708621] sh (7626): drop_caches: 3 [ 293.711386] sh (7628): drop_caches: 3 [ 293.711825] sh (7627): drop_caches: 3 [ 293.716738] sh (7630): drop_caches: 3 [ 293.719613] sh (7632): drop_caches: 3 [ 293.720971] sh (7633): drop_caches: 3 [ 293.727741] sh (7634): drop_caches: 3 [ 293.730783] sh (7636): drop_caches: 3 [ 293.732681] sh (7635): drop_caches: 3 [ 293.732988] sh (7637): drop_caches: 3 [ 293.738836] sh (7639): drop_caches: 3 [ 293.740568] sh (7641): drop_caches: 3 [ 293.743053] sh (7640): drop_caches: 3 [ 293.821889] ------------[ cut here ]------------ [ 293.824654] kernel BUG at fs/f2fs/node.c:3334! [ 293.826226] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 293.828713] CPU: 0 PID: 7653 Comm: umount Tainted: G OE 5.17.0-rc1-custom #1 [ 293.830946] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 293.832526] RIP: 0010:f2fs_destroy_node_manager+0x33f/0x350 [f2fs] [ 293.833905] Code: e8 d6 3d f9 f9 48 8b 45 d0 65 48 2b 04 25 28 00 00 00 75 1a 48 81 c4 28 03 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b [ 293.837783] RSP: 0018:ffffb04ec31e7a20 EFLAGS: 00010202 [ 293.839062] RAX: 0000000000000001 RBX: ffff9df947db2eb8 RCX: 0000000080aa0072 [ 293.840666] RDX: 0000000000000000 RSI: ffffe86c0432a140 RDI: ffffffffc0b72a21 [ 293.842261] RBP: ffffb04ec31e7d70 R08: ffff9df94ca85780 R09: 0000000080aa0072 [ 293.843909] R10: ffff9df94ca85700 R11: ffff9df94e1ccf58 R12: ffff9df947db2e00 [ 293.845594] R13: ffff9df947db2ed0 R14: ffff9df947db2eb8 R15: ffff9df947db2eb8 [ 293.847855] FS: 00007f5a97379800(0000) GS:ffff9dfa77c00000(0000) knlGS:0000000000000000 [ 293.850647] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 293.852940] CR2: 00007f5a97528730 CR3: 000000010bc76005 CR4: 0000000000370ef0 [ 293.854680] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 293.856423] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 293.858380] Call Trace: [ 293.859302] <TASK> [ 293.860311] ? ttwu_do_wakeup+0x1c/0x170 [ 293.861800] ? ttwu_do_activate+0x6d/0xb0 [ 293.863057] ? _raw_spin_unlock_irqrestore+0x29/0x40 [ 293.864411] ? try_to_wake_up+0x9d/0x5e0 [ 293.865618] ? debug_smp_processor_id+0x17/0x20 [ 293.866934] ? debug_smp_processor_id+0x17/0x20 [ 293.868223] ? free_unref_page+0xbf/0x120 [ 293.869470] ? __free_slab+0xcb/0x1c0 [ 293.870614] ? preempt_count_add+0x7a/0xc0 [ 293.871811] ? __slab_free+0xa0/0x2d0 [ 293.872918] ? __wake_up_common_lock+0x8a/0xc0 [ 293.874186] ? __slab_free+0xa0/0x2d0 [ 293.875305] ? free_inode_nonrcu+0x20/0x20 [ 293.876466] ? free_inode_nonrcu+0x20/0x20 [ 293.877650] ? debug_smp_processor_id+0x17/0x20 [ 293.878949] ? call_rcu+0x11a/0x240 [ 293.880060] ? f2fs_destroy_stats+0x59/0x60 [f2fs] [ 293.881437] ? kfree+0x1fe/0x230 [ 293.882674] f2fs_put_super+0x160/0x390 [f2fs] [ 293.883978] generic_shutdown_super+0x7a/0x120 [ 293.885274] kill_block_super+0x27/0x50 [ 293.886496] kill_f2fs_super+0x7f/0x100 [f2fs] [ 293.887806] deactivate_locked_super+0x35/0xa0 [ 293.889271] deactivate_super+0x40/0x50 [ 293.890513] cleanup_mnt+0x139/0x190 [ 293.891689] __cleanup_mnt+0x12/0x20 [ 293.892850] task_work_run+0x64/0xa0 [ 293.894035] exit_to_user_mode_prepare+0x1b7/ ---truncated---

AI Analysis

Technical Summary

CVE-2022-49255 is a vulnerability identified in the Linux kernel's F2FS (Flash-Friendly File System) implementation. The issue arises from a missing free operation for a node identifier (nid) in the function f2fs_handle_failed_inode, which can lead to orphaned inodes and subsequent file system inconsistencies. The vulnerability manifests as errors such as 'Buffer I/O error on dev dm-1' and kernel BUGs related to node management, specifically in the f2fs_destroy_node_manager function. These errors indicate potential memory management flaws and improper cleanup of inode structures within the F2FS module. The problem can cause file system corruption, loss of orphan inodes, and may require running fsck (file system check) to repair the affected file system. The kernel logs show that the issue can lead to kernel panics or crashes, which affect system stability and availability. The vulnerability was detected through failure in xfstests/generic/475, a generic file system test, and has been addressed by a patch that fixes the missing free nid operation. There is no indication that this vulnerability requires user interaction or elevated privileges to be exploited, but it affects the core kernel file system code, which is critical for system operation. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet.

Potential Impact

For European organizations, this vulnerability poses a risk primarily to systems running Linux kernels with the vulnerable F2FS implementation, especially those using flash storage devices formatted with F2FS. The impact includes potential data loss due to orphaned inodes and file system corruption, which can disrupt business operations relying on data integrity and availability. Systems may experience unexpected crashes or kernel panics, leading to downtime and potential loss of productivity. Critical infrastructure, cloud service providers, and enterprises using Linux-based storage solutions could face operational disruptions. Since F2FS is optimized for flash storage, organizations utilizing modern SSDs or embedded Linux devices with F2FS may be more exposed. The lack of known exploits reduces immediate risk, but the vulnerability's nature means that if exploited, it could compromise system stability and data integrity, affecting confidentiality indirectly if data loss leads to exposure or recovery processes.

Mitigation Recommendations

Organizations should promptly apply the official Linux kernel patches that address this vulnerability once available. Until patches are applied, it is advisable to avoid using F2FS on critical systems or to limit the use of affected kernel versions. Regular backups of data stored on F2FS partitions should be maintained to mitigate data loss risks. Running periodic file system checks (fsck) on F2FS partitions can help detect and repair orphaned inodes early. Monitoring kernel logs for related error messages can provide early warning signs of exploitation or system instability. For environments where patching is delayed, consider isolating vulnerable systems or using alternative file systems that do not exhibit this flaw. Additionally, ensure that kernel updates are tested in staging environments to prevent unintended disruptions. Coordination with Linux distribution vendors for timely updates and advisories is recommended.