Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2021-47638— ubifs: rename_whiteout: Fix double free for whiteout_ui->data

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于rename_whiteout操作中的双重释放。

CVSS 7.8 · High EPSS 0.26% · P17

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798< 8b3c7be16f3f4dfd6e15ac651484e59d3fa36274 affected
9e0a1fff8db56eaaebb74b4a3ef65f86811c4798< 2b3236ecf96db7af5836e1366ce39ace8ce832fa affected
9e0a1fff8db56eaaebb74b4a3ef65f86811c4798< 14276d38c89a170363e90b6ac0a53c3cf61b87fc affected
9e0a1fff8db56eaaebb74b4a3ef65f86811c4798< a90e2dbe66d2647ff95a0442ad2e86482d977fd8 affected
9e0a1fff8db56eaaebb74b4a3ef65f86811c4798< 2ad07009c459e56ebdcc089d850d664660fdb742 affected
9e0a1fff8db56eaaebb74b4a3ef65f86811c4798< b9a937f096e608b3368c1abc920d4d640ba2c94f affected
9e0a1fff8db56eaaebb74b4a3ef65f86811c4798< 6d7a158a7363c1f6604aa47ae1a280a5c65123dd affected
9e0a1fff8db56eaaebb74b4a3ef65f86811c4798< 40a8f0d5e7b3999f096570edab71c345da812e3e affected
… +10 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2021-47638

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
ubifs: rename_whiteout: Fix double free for whiteout_ui->data
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: ubifs: rename_whiteout: Fix double free for whiteout_ui->data 'whiteout_ui->data' will be freed twice if space budget fail for rename whiteout operation as following process: rename_whiteout dev = kmalloc whiteout_ui->data = dev kfree(whiteout_ui->data) // Free first time iput(whiteout) ubifs_free_inode kfree(ui->data) // Double free! KASAN reports: ================================================================== BUG: KASAN: double-free or invalid-free in ubifs_free_inode+0x4f/0x70 Call Trace: kfree+0x117/0x490 ubifs_free_inode+0x4f/0x70 [ubifs] i_callback+0x30/0x60 rcu_do_batch+0x366/0xac0 __do_softirq+0x133/0x57f Allocated by task 1506: kmem_cache_alloc_trace+0x3c2/0x7a0 do_rename+0x9b7/0x1150 [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 Freed by task 1506: kfree+0x117/0x490 do_rename.cold+0x53/0x8a [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 The buggy address belongs to the object at ffff88810238bed8 which belongs to the cache kmalloc-8 of size 8 ================================================================== Let ubifs_free_inode() free 'whiteout_ui->data'. BTW, delete unused assignment 'whiteout_ui->data_len = 0', process 'ubifs_evict_inode() -> ubifs_jnl_delete_inode() -> ubifs_jnl_write_inode()' doesn't need it (because 'inc_nlink(whiteout)' won't be excuted by 'goto out_release', and the nlink of whiteout inode is 0).
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于rename_whiteout操作中的双重释放。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 9e0a1fff8db56eaaebb74b4a3ef65f86811c4798 ~ 8b3c7be16f3f4dfd6e15ac651484e59d3fa36274 -
Linux Linux 4.9 -

II. Public POCs for CVE-2021-47638

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2021-47638

请登录查看更多情报信息。

Patches & Fixes for CVE-2021-47638 (8)

Same Patch Batch · Linux · 2025-02-26 · 706 CVEs total

CVE-2022-49561 9.8 CRITICAL netfilter: conntrack: re-fetch conntrack after insertion
CVE-2022-49149 9.8 CRITICAL rxrpc: Fix call timer start racing with call destruction
CVE-2022-49356 9.8 CRITICAL SUNRPC: Trap RDMA segment overflows
CVE-2022-49280 9.8 CRITICAL NFSD: prevent underflow in nfssvc_decode_writeargs()
CVE-2022-49362 9.8 CRITICAL NFSD: Fix potential use-after-free in nfsd_file_put()
CVE-2022-49260 9.8 CRITICAL crypto: hisilicon/sec - fix the aead software fallback for engine
CVE-2022-49418 9.8 CRITICAL NFSv4: Fix free of uninitialized nfs4_label on referral lookup.
CVE-2022-49407 9.8 CRITICAL dlm: fix plock invalid read
CVE-2022-49201 9.8 CRITICAL ibmvnic: fix race between xmit and reset
CVE-2022-49194 9.8 CRITICAL net: bcmgenet: Use stronger register read/writes to assure ordering
CVE-2022-49093 9.8 CRITICAL skbuff: fix coalescing for page_pool fragment recycling
CVE-2022-49094 9.8 CRITICAL net/tls: fix slab-out-of-bounds bug in decrypt_internal
CVE-2022-49058 9.1 CRITICAL cifs: potential buffer overflow in handling symlinks
CVE-2022-49111 8.8 HIGH Bluetooth: Fix use after free in hci_send_acl
CVE-2022-49535 8.8 HIGH scsi: lpfc: Fix null pointer dereference after failing to issue FLOGI and PLOGI
CVE-2022-49238 8.8 HIGH ath11k: free peer for station when disconnect from AP for QCA6390/WCN6855
CVE-2022-49519 8.8 HIGH ath10k: skip ath10k_halt during suspend for driver state RESTARTING
CVE-2022-49138 8.8 HIGH Bluetooth: hci_event: Ignore multiple conn complete events
CVE-2022-49471 8.8 HIGH rtw89: cfo: check mac_id to avoid out-of-bounds
CVE-2022-49159 8.8 HIGH scsi: qla2xxx: Implement ref count for SRB

Showing top 20 of 706 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2021-47638

No comments yet

Leave a comment