gsd-2021-47089
Vulnerability from gsd
Modified
2024-03-01 06:04
Details
In the Linux kernel, the following vulnerability has been resolved:
kfence: fix memory leak when cat kfence objects
Hulk robot reported a kmemleak problem:
unreferenced object 0xffff93d1d8cc02e8 (size 248):
comm "cat", pid 23327, jiffies 4624670141 (age 495992.217s)
hex dump (first 32 bytes):
00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@..............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
seq_open+0x2a/0x80
full_proxy_open+0x167/0x1e0
do_dentry_open+0x1e1/0x3a0
path_openat+0x961/0xa20
do_filp_open+0xae/0x120
do_sys_openat2+0x216/0x2f0
do_sys_open+0x57/0x80
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
unreferenced object 0xffff93d419854000 (size 4096):
comm "cat", pid 23327, jiffies 4624670141 (age 495992.217s)
hex dump (first 32 bytes):
6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0
30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda12-
backtrace:
seq_read_iter+0x313/0x440
seq_read+0x14b/0x1a0
full_proxy_read+0x56/0x80
vfs_read+0xa5/0x1b0
ksys_read+0xa0/0xf0
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
I find that we can easily reproduce this problem with the following
commands:
cat /sys/kernel/debug/kfence/objects
echo scan > /sys/kernel/debug/kmemleak
cat /sys/kernel/debug/kmemleak
The leaked memory is allocated in the stack below:
do_syscall_64
do_sys_open
do_dentry_open
full_proxy_open
seq_open ---> alloc seq_file
vfs_read
full_proxy_read
seq_read
seq_read_iter
traverse ---> alloc seq_buf
And it should have been released in the following process:
do_syscall_64
syscall_exit_to_user_mode
exit_to_user_mode_prepare
task_work_run
____fput
__fput
full_proxy_release ---> free here
However, the release function corresponding to file_operations is not
implemented in kfence. As a result, a memory leak occurs. Therefore,
the solution to this problem is to implement the corresponding release
function.
Aliases
{
"gsd": {
"metadata": {
"exploitCode": "unknown",
"remediation": "unknown",
"reportConfidence": "confirmed",
"type": "vulnerability"
},
"osvSchema": {
"aliases": [
"CVE-2021-47089"
],
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nkfence: fix memory leak when cat kfence objects\n\nHulk robot reported a kmemleak problem:\n\n unreferenced object 0xffff93d1d8cc02e8 (size 248):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@..............\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\n backtrace:\n seq_open+0x2a/0x80\n full_proxy_open+0x167/0x1e0\n do_dentry_open+0x1e1/0x3a0\n path_openat+0x961/0xa20\n do_filp_open+0xae/0x120\n do_sys_openat2+0x216/0x2f0\n do_sys_open+0x57/0x80\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n unreferenced object 0xffff93d419854000 (size 4096):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0\n 30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda12-\n backtrace:\n seq_read_iter+0x313/0x440\n seq_read+0x14b/0x1a0\n full_proxy_read+0x56/0x80\n vfs_read+0xa5/0x1b0\n ksys_read+0xa0/0xf0\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nI find that we can easily reproduce this problem with the following\ncommands:\n\n\tcat /sys/kernel/debug/kfence/objects\n\techo scan \u003e /sys/kernel/debug/kmemleak\n\tcat /sys/kernel/debug/kmemleak\n\nThe leaked memory is allocated in the stack below:\n\n do_syscall_64\n do_sys_open\n do_dentry_open\n full_proxy_open\n seq_open ---\u003e alloc seq_file\n vfs_read\n full_proxy_read\n seq_read\n seq_read_iter\n traverse ---\u003e alloc seq_buf\n\nAnd it should have been released in the following process:\n\n do_syscall_64\n syscall_exit_to_user_mode\n exit_to_user_mode_prepare\n task_work_run\n ____fput\n __fput\n full_proxy_release ---\u003e free here\n\nHowever, the release function corresponding to file_operations is not\nimplemented in kfence. As a result, a memory leak occurs. Therefore,\nthe solution to this problem is to implement the corresponding release\nfunction.",
"id": "GSD-2021-47089",
"modified": "2024-03-01T06:04:48.327067Z",
"schema_version": "1.4.0"
}
},
"namespaces": {
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"CVE_data_meta": {
"ASSIGNER": "cve@kernel.org",
"ID": "CVE-2021-47089",
"STATE": "PUBLIC"
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"affects": {
"vendor": {
"vendor_data": [
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"product": {
"product_data": [
{
"product_name": "Linux",
"version": {
"version_data": [
{
"version_affected": "\u003c",
"version_name": "0ce20dd84089",
"version_value": "2f06c8293d27"
},
{
"version_value": "not down converted",
"x_cve_json_5_version_data": {
"defaultStatus": "affected",
"versions": [
{
"status": "affected",
"version": "5.12"
},
{
"lessThan": "5.12",
"status": "unaffected",
"version": "0",
"versionType": "custom"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.12",
"versionType": "custom"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "5.16",
"versionType": "original_commit_for_fix"
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"data_format": "MITRE",
"data_type": "CVE",
"data_version": "4.0",
"description": {
"description_data": [
{
"lang": "eng",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkfence: fix memory leak when cat kfence objects\n\nHulk robot reported a kmemleak problem:\n\n unreferenced object 0xffff93d1d8cc02e8 (size 248):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@..............\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\n backtrace:\n seq_open+0x2a/0x80\n full_proxy_open+0x167/0x1e0\n do_dentry_open+0x1e1/0x3a0\n path_openat+0x961/0xa20\n do_filp_open+0xae/0x120\n do_sys_openat2+0x216/0x2f0\n do_sys_open+0x57/0x80\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n unreferenced object 0xffff93d419854000 (size 4096):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0\n 30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda12-\n backtrace:\n seq_read_iter+0x313/0x440\n seq_read+0x14b/0x1a0\n full_proxy_read+0x56/0x80\n vfs_read+0xa5/0x1b0\n ksys_read+0xa0/0xf0\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nI find that we can easily reproduce this problem with the following\ncommands:\n\n\tcat /sys/kernel/debug/kfence/objects\n\techo scan \u003e /sys/kernel/debug/kmemleak\n\tcat /sys/kernel/debug/kmemleak\n\nThe leaked memory is allocated in the stack below:\n\n do_syscall_64\n do_sys_open\n do_dentry_open\n full_proxy_open\n seq_open ---\u003e alloc seq_file\n vfs_read\n full_proxy_read\n seq_read\n seq_read_iter\n traverse ---\u003e alloc seq_buf\n\nAnd it should have been released in the following process:\n\n do_syscall_64\n syscall_exit_to_user_mode\n exit_to_user_mode_prepare\n task_work_run\n ____fput\n __fput\n full_proxy_release ---\u003e free here\n\nHowever, the release function corresponding to file_operations is not\nimplemented in kfence. As a result, a memory leak occurs. Therefore,\nthe solution to this problem is to implement the corresponding release\nfunction."
}
]
},
"generator": {
"engine": "bippy-4986f5686161"
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"problemtype": {
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"reference_data": [
{
"name": "https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48",
"refsource": "MISC",
"url": "https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48"
},
{
"name": "https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634",
"refsource": "MISC",
"url": "https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634"
}
]
}
},
"nvd.nist.gov": {
"cve": {
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkfence: fix memory leak when cat kfence objects\n\nHulk robot reported a kmemleak problem:\n\n unreferenced object 0xffff93d1d8cc02e8 (size 248):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 00 40 85 19 d4 93 ff ff 00 10 00 00 00 00 00 00 .@..............\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\n backtrace:\n seq_open+0x2a/0x80\n full_proxy_open+0x167/0x1e0\n do_dentry_open+0x1e1/0x3a0\n path_openat+0x961/0xa20\n do_filp_open+0xae/0x120\n do_sys_openat2+0x216/0x2f0\n do_sys_open+0x57/0x80\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n unreferenced object 0xffff93d419854000 (size 4096):\n comm \"cat\", pid 23327, jiffies 4624670141 (age 495992.217s)\n hex dump (first 32 bytes):\n 6b 66 65 6e 63 65 2d 23 32 35 30 3a 20 30 78 30 kfence-#250: 0x0\n 30 30 30 30 30 30 30 37 35 34 62 64 61 31 32 2d 0000000754bda12-\n backtrace:\n seq_read_iter+0x313/0x440\n seq_read+0x14b/0x1a0\n full_proxy_read+0x56/0x80\n vfs_read+0xa5/0x1b0\n ksys_read+0xa0/0xf0\n do_syscall_64+0x33/0x40\n entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\nI find that we can easily reproduce this problem with the following\ncommands:\n\n\tcat /sys/kernel/debug/kfence/objects\n\techo scan \u003e /sys/kernel/debug/kmemleak\n\tcat /sys/kernel/debug/kmemleak\n\nThe leaked memory is allocated in the stack below:\n\n do_syscall_64\n do_sys_open\n do_dentry_open\n full_proxy_open\n seq_open ---\u003e alloc seq_file\n vfs_read\n full_proxy_read\n seq_read\n seq_read_iter\n traverse ---\u003e alloc seq_buf\n\nAnd it should have been released in the following process:\n\n do_syscall_64\n syscall_exit_to_user_mode\n exit_to_user_mode_prepare\n task_work_run\n ____fput\n __fput\n full_proxy_release ---\u003e free here\n\nHowever, the release function corresponding to file_operations is not\nimplemented in kfence. As a result, a memory leak occurs. Therefore,\nthe solution to this problem is to implement the corresponding release\nfunction."
}
],
"id": "CVE-2021-47089",
"lastModified": "2024-03-05T13:41:01.900",
"metrics": {},
"published": "2024-03-04T18:15:07.560",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0129ab1f268b6cf88825eae819b9b84aa0a85634"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2f06c8293d27f6337f907042c602c9c953988c48"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
}
}
}
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