CVE-2021-46982
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2021
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
f2fs: compress: fix race condition of overwrite vs truncate
In the Linux kernel, the following vulnerability has been resolved: f2fs: compress: fix race condition of overwrite vs truncate pos_fsstress testcase complains a panic as belew: ------------[ cut here ]------------ kernel BUG at fs/f2fs/compress.c:1082! invalid opcode: 0000 [#1] SMP PTI CPU: 4 PID: 2753477 Comm: kworker/u16:2 Tainted: G OE 5.12.0-rc1-custom #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: writeback wb_workfn (flush-252:16) RIP: 0010:prepare_compress_overwrite+0x4c0/0x760 [f2fs] Call Trace: f2fs_prepare_compress_overwrite+0x5f/0x80 [f2fs] f2fs_write_cache_pages+0x468/0x8a0 [f2fs] f2fs_write_data_pages+0x2a4/0x2f0 [f2fs] do_writepages+0x38/0xc0 __writeback_single_inode+0x44/0x2a0 writeback_sb_inodes+0x223/0x4d0 __writeback_inodes_wb+0x56/0xf0 wb_writeback+0x1dd/0x290 wb_workfn+0x309/0x500 process_one_work+0x220/0x3c0 worker_thread+0x53/0x420 kthread+0x12f/0x150 ret_from_fork+0x22/0x30 The root cause is truncate() may race with overwrite as below, so that one reference count left in page can not guarantee the page attaching in mapping tree all the time, after truncation, later find_lock_page() may return NULL pointer. - prepare_compress_overwrite - f2fs_pagecache_get_page - unlock_page - f2fs_setattr - truncate_setsize - truncate_inode_page - delete_from_page_cache - find_lock_page Fix this by avoiding referencing updated page.
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
unaffected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 4c8ff7095bef64fc47e996a938f7d57f9e077da3 | affected | git | 5639b73fd3bc6fc8ca72e3a9ac15aacaabd7ebff | Unavailable | None listed |
| 4c8ff7095bef64fc47e996a938f7d57f9e077da3 | affected | git | 64acb100fe3beb5d20184d0ae3307235bd3555c4 | Unavailable | None listed |
| 4c8ff7095bef64fc47e996a938f7d57f9e077da3 | affected | git | 936158b15e2648253afb824d252c910c496d34b5 | Unavailable | None listed |
| 4c8ff7095bef64fc47e996a938f7d57f9e077da3 | affected | git | a949dc5f2c5cfe0c910b664650f45371254c0744 | Unavailable | None listed |
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
affected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 5.6 | affected | Unavailable | Unavailable | Unavailable | None listed |
| 0 | unaffected | semver | 5.6 | Unavailable | None listed |
| 5.10.38 | unaffected | semver | Unavailable | 5.10.* | None listed |
| 5.11.22 | unaffected | semver | Unavailable | 5.11.* | None listed |
| 5.12.5 | unaffected | semver | Unavailable | 5.12.* | None listed |
| 5.13 | unaffected | original_commit_for_fix | Unavailable | * | None listed |