ext4: fix bug_on in ext4_writepages
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 5 fixed, 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-617.
Summary
In the Linux kernel, the following vulnerability has been resolved: ext4: fix bug_on in ext4_writepages we got issue as follows: EXT4-fs error (device loop0): ext4_mb_generate_buddy:1141: group 0, block bitmap and bg descriptor inconsistent: 25 vs 31513 free cls ------------[ cut here ]------------ kernel BUG at fs/ext4/inode.c:2708! invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 2 PID: 2147 Comm: rep Not tainted 5.18.0-rc2-next-20220413+ #155 RIP: 0010:ext4_writepages+0x1977/0x1c10 RSP: 0018:ffff88811d3e7880 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88811c098000 RDX: 0000000000000000 RSI: ffff88811c098000 RDI: 0000000000000002 RBP: ffff888128140f50 R08: ffffffffb1ff6387 R09: 0000000000000000 R10: 0000000000000007 R11: ffffed10250281ea R12: 0000000000000001 R13: 00000000000000a4 R14: ffff88811d3e7bb8 R15: ffff888128141028 FS: 00007f443aed9740(0000) GS:ffff8883aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020007200 CR3: 000000011c2a4000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> do_writepages+0x130/0x3a0 filemap_fdatawrite_wbc+0x83/0xa0 filemap_flush+0xab/0xe0 ext4_alloc_da_blocks+0x51/0x120 __ext4_ioctl+0x1534/0x3210 __x64_sys_ioctl+0x12c/0x170 do_syscall_64+0x3b/0x90 It may happen as follows: 1. write inline_data inode vfs_write new_sync_write ext4_file_write_iter ext4_buffered_write_iter generic_perform_write ext4_da_write_begin ext4_da_write_inline_data_begin -> If inline data size too small will allocate block to write, then mapping will has dirty page ext4_da_convert_inline_data_to_extent ->clear EXT4_STATE_MAY_INLINE_DATA 2. fallocate do_vfs_ioctl ioctl_preallocate vfs_fallocate ext4_fallocate ext4_convert_inline_data ext4_convert_inline_data_nolock ext4_map_blocks -> fail will goto restore data ext4_restore_inline_data ext4_create_inline_data ext4_write_inline_data ext4_set_inode_state -> set inode EXT4_STATE_MAY_INLINE_DATA 3. writepages __ext4_ioctl ext4_alloc_da_blocks filemap_flush filemap_fdatawrite_wbc do_writepages ext4_writepages if (ext4_has_inline_data(inode)) BUG_ON(ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) The root cause of this issue is we destory inline data until call ext4_writepages under delay allocation mode. But there maybe already convert from inline to extent. To solve this issue, we call filemap_flush first..
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.8 and later | 4.9.318, 4.14.283, 4.19.247, 5.4.198, 5.10.121, 5.15.46, 5.17.14, 5.18.3, 5.19 | Patch available | CNA |
- Linux VendorLinux Affected 3.8 and later Fixed in 4.9.318, 4.14.283, 4.19.247, 5.4.198, 5.10.121, 5.15.46, 5.17.14, 5.18.3, 5.19 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 4.9.318; 4.10 to before 4.14.283; 4.15 to before 4.19.247; 4.20 to before 5.4.198; 5.5 to before 5.10.121; 5.11 to before 5.15.46; 5.16 to before 5.17.14; 5.18 to before 5.18.3 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.9.318; 4.10 to before 4.14.283; 4.15 to before 4.19.247; 4.20 to before 5.4.198; 5.5 to before 5.10.121; 5.11 to before 5.15.46; 5.16 to before 5.17.14; 5.18 to before 5.18.3 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.9.318, 4.14.283, 4.19.247, 5.4.198, 5.10.121, 5.15.46, 5.17.14, 5.18.3, 5.19
Red Hat 2 advisories
- RHSA-2022:8267 Released 2022-11-15 · Red Hat rating Moderatekernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-162.6.1.el9_1
- Red Hat Enterprise Linux AppStream (v. 9) kernel-debug-devel-5.14.0-162.6.1.el9_1, kernel-debug-devel-matched-5.14.0-162.6.1.el9_1, kernel-devel-5.14.0-162.6.1.el9_1 +5
- Red Hat Enterprise Linux BaseOS (v. 9) bpftool-5.14.0-162.6.1.el9_1, kernel-5.14.0-162.6.1.el9_1, kernel-abi-stablelists-5.14.0-162.6.1.el9_1 +14
- RHSA-2022:7683 Released 2022-11-08 · Red Hat rating Moderatekernel security, bug fix, and enhancement update
- Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-425.3.1.el8
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-425.3.1.el8, kernel-4.18.0-425.3.1.el8, kernel-abi-stablelists-4.18.0-425.3.1.el8 +19
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | RHSA-2022:7683 |
| Red Hat CodeReady Linux Builder (v. 9) | Fixed | RHSA-2022:8267 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2022:8267 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2022:7683 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2022:8267 |
Not affected: 2 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2022-49347
- 2026-10-03 Alias added: GHSA-pqc9-xfp2-368x
References
Patch 9
- https://git.kernel.org/stable/c/19918ec7717d87d5ab825884a46b26b21375d7ce
- https://git.kernel.org/stable/c/b2b78f5bf2d453dda3903955efee059260787a42
- https://git.kernel.org/stable/c/de1732b5c1693ad489c5d254f124f67cb775f37d
- https://git.kernel.org/stable/c/73fd5b19285197078ee8a2e651d75d5b094a4de9
- https://git.kernel.org/stable/c/1b061af037646c9cdb0afd8a8d2f1e1c06285866
- https://git.kernel.org/stable/c/18a759f7f99f0b65a08ff5b7e745fc405a42bde4
- https://git.kernel.org/stable/c/1cde35417edc0370fb0179a4e38b78a15350a8d0
- https://git.kernel.org/stable/c/013f12bdedb96816aaa27ee04349f4433d361f52
- https://git.kernel.org/stable/c/ef09ed5d37b84d18562b30cf7253e57062d0db05
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- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2022-49347 · CVE Program
- CVE-2022-49347 · NVD
- FIRST EPSS
- GHSA-pqc9-xfp2-368x · GitHub Advisory Database · CC BY 4.0
- CVE-2022-49347 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences