CVE-2024-40949
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2024-40949
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-40949.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2024-40949
- Downstream
- Published
- 2024-07-12T12:31:54Z
- Modified
- 2025-10-17T07:49:48.352268Z
- Summary
- mm: shmem: fix getting incorrect lruvec when replacing a shmem folio
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
mm: shmem: fix getting incorrect lruvec when replacing a shmem folio
When testing shmem swapin, I encountered the warning below on my machine. The reason is that replacing an old shmem folio with a new one causes memcgroupmigrate() to clear the old folio's memcg data. As a result, the old folio cannot get the correct memcg's lruvec needed to remove itself from the LRU list when it is being freed. This could lead to possible serious problems, such as LRU list crashes due to holding the wrong LRU lock, and incorrect LRU statistics.
To fix this issue, we can fallback to use the memcgroupreplace_folio() to replace the old shmem folio.
[ 5241.100311] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d9960 [ 5241.100317] head: order:4 mapcount:0 entiremapcount:0 nrpagesmapped:0 pincount:0 [ 5241.100319] flags: 0x17fffe0000040068(uptodate|lru|head|swapbacked|node=0|zone=2|lastcpupid=0x3ffff) [ 5241.100323] raw: 17fffe0000040068 fffffdffd6687948 fffffdffd69ae008 0000000000000000 [ 5241.100325] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 5241.100326] head: 17fffe0000040068 fffffdffd6687948 fffffdffd69ae008 0000000000000000 [ 5241.100327] head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 5241.100328] head: 17fffe0000000204 fffffdffd6665801 ffffffffffffffff 0000000000000000 [ 5241.100329] head: 0000000a00000010 0000000000000000 00000000ffffffff 0000000000000000 [ 5241.100330] page dumped because: VMWARNONONCEFOLIO(!memcg && !memcgroupdisabled()) [ 5241.100338] ------------[ cut here ]------------ [ 5241.100339] WARNING: CPU: 19 PID: 78402 at include/linux/memcontrol.h:775 foliolruveclockirqsave+0x140/0x150 [...] [ 5241.100374] pc : foliolruveclockirqsave+0x140/0x150 [ 5241.100375] lr : foliolruveclockirqsave+0x138/0x150 [ 5241.100376] sp : ffff80008b38b930 [...] [ 5241.100398] Call trace: [ 5241.100399] foliolruveclockirqsave+0x140/0x150 [ 5241.100401] _pagecacherelease+0x90/0x300 [ 5241.100404] _folioput+0x50/0x108 [ 5241.100406] shmemreplacefolio+0x1b4/0x240 [ 5241.100409] shmemswapinfolio+0x314/0x528 [ 5241.100411] shmemgetfoliogfp+0x3b4/0x930 [ 5241.100412] shmemfault+0x74/0x160 [ 5241.100414] _dofault+0x40/0x218 [ 5241.100417] dosharedfault+0x34/0x1b0 [ 5241.100419] dofault+0x40/0x168 [ 5241.100420] handleptefault+0x80/0x228 [ 5241.100422] _handlemmfault+0x1c4/0x440 [ 5241.100424] handlemmfault+0x60/0x1f0 [ 5241.100426] dopagefault+0x120/0x488 [ 5241.100429] dotranslationfault+0x4c/0x68 [ 5241.100431] domemabort+0x48/0xa0 [ 5241.100434] el0da+0x38/0xc0 [ 5241.100436] el0t64synchandler+0x68/0xc0 [ 5241.100437] el0t64sync+0x14c/0x150 [ 5241.100439] ---[ end trace 0000000000000000 ]---
[baolin.wang@linux.alibaba.com: remove less helpful comments, per Matthew]
- References
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced85ce2c517ade0d51b7ad95f2e88be9bbe294379aFixed8c6c3719ebb7913f8a665d11816d2e38b0eadbab
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced85ce2c517ade0d51b7ad95f2e88be9bbe294379aFixed9094b4a1c76cfe84b906cc152bab34d4ba26fa5c
Affected versions
v6.*
Database specific
vanir_signatures
[
{
"signature_type": "Line",
"id": "CVE-2024-40949-87aaab4a",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@9094b4a1c76cfe84b906cc152bab34d4ba26fa5c",
"signature_version": "v1",
"target": {
"file": "mm/shmem.c"
},
"digest": {
"threshold": 0.9,
"line_hashes": [
"249166782778335019435745990618143023935",
"8885100464711786498387210662089916616",
"229507870597849782057502586241113327531",
"193958315667464994938924123399107965561"
]
},
"deprecated": false
},
{
"signature_type": "Function",
"id": "CVE-2024-40949-972388f0",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@9094b4a1c76cfe84b906cc152bab34d4ba26fa5c",
"signature_version": "v1",
"target": {
"function": "shmem_replace_folio",
"file": "mm/shmem.c"
},
"digest": {
"function_hash": "223997310535934612363855601227217867415",
"length": 1116.0
},
"deprecated": false
},
{
"signature_type": "Line",
"id": "CVE-2024-40949-ab7a8123",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@8c6c3719ebb7913f8a665d11816d2e38b0eadbab",
"signature_version": "v1",
"target": {
"file": "mm/shmem.c"
},
"digest": {
"threshold": 0.9,
"line_hashes": [
"249166782778335019435745990618143023935",
"8885100464711786498387210662089916616",
"229507870597849782057502586241113327531",
"193958315667464994938924123399107965561"
]
},
"deprecated": false
},
{
"signature_type": "Function",
"id": "CVE-2024-40949-e612eb7c",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@8c6c3719ebb7913f8a665d11816d2e38b0eadbab",
"signature_version": "v1",
"target": {
"function": "shmem_replace_folio",
"file": "mm/shmem.c"
},
"digest": {
"function_hash": "223997310535934612363855601227217867415",
"length": 1116.0
},
"deprecated": false
}
]