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CVE-2024-40914

Disclosure Date: July 12, 2024 •
CVE-2024-40914
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

In the Linux kernel, the following vulnerability has been resolved:

mm/huge_memory: don’t unpoison huge_zero_folio

When I did memory failure tests recently, below panic occurs:

kernel BUG at include/linux/mm.h:1135!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14
RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0
RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246
RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8
RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0
RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492
R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00
FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0
Call Trace:
<TASK>
do_shrink_slab+0x14f/0x6a0
shrink_slab+0xca/0x8c0
shrink_node+0x2d0/0x7d0
balance_pgdat+0x33a/0x720
kswapd+0x1f3/0x410
kthread+0xd5/0x100
ret_from_fork+0x2f/0x50
ret_from_fork_asm+0x1a/0x30
</TASK>
Modules linked in: mce_inject hwpoison_inject
—–[ end trace 0000000000000000 ]—-
RIP: 0010:shrink_huge_zero_page_scan+0x168/0x1a0
RSP: 0018:ffff9933c6c57bd0 EFLAGS: 00000246
RAX: 000000000000003e RBX: 0000000000000000 RCX: ffff88f61fc5c9c8
RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff88f61fc5c9c0
RBP: ffffcd7c446b0000 R08: ffffffff9a9405f0 R09: 0000000000005492
R10: 00000000000030ea R11: ffffffff9a9405f0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88e703c4ac00
FS: 0000000000000000(0000) GS:ffff88f61fc40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f4da6e9878 CR3: 0000000c71048000 CR4: 00000000000006f0

The root cause is that HWPoison flag will be set for huge_zero_folio
without increasing the folio refcnt. But then unpoison_memory() will
decrease the folio refcnt unexpectedly as it appears like a successfully
hwpoisoned folio leading to VM_BUG_ON_PAGE(page_ref_count(page) == 0) when
releasing huge_zero_folio.

Skip unpoisoning huge_zero_folio in unpoison_memory() to fix this issue.
We’re not prepared to unpoison huge_zero_folio yet.

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CVSS V3 Severity and Metrics
Base Score:
None
Impact Score:
Unknown
Exploitability Score:
Unknown
Vector:
Unknown
Attack Vector (AV):
Unknown
Attack Complexity (AC):
Unknown
Privileges Required (PR):
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User Interaction (UI):
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Scope (S):
Unknown
Confidentiality (C):
Unknown
Integrity (I):
Unknown
Availability (A):
Unknown

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
Linux 688bb46ad339
Linux b2494506f306
Linux not down converted
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • Linux

Products

  • Linux
Technical Analysis