CVE-2023-53665

Except for initial reference, mddev->kobject is referenced by rdev->kobject, and if the last rdev is freed, there is no guarantee that mddev is still valid. Hence mddev should not be used anymore after export_rdev().

This problem can be triggered by following test for mdadm at very low rate:

New file: mdadm/tests/23rdev-lifetime

devname=${dev0##*/} devt=cat /sys/block/$devname/dev pid="" runtime=2

cleanuptest() { pill -9 $pid echo clear > /sys/block/md0/md/array_state }

trap 'cleanuptest' EXIT

addbysysfs() { while true; do echo $devt > /sys/block/md0/md/new_dev done }

removebysysfs(){ while true; do echo remove > /sys/block/md0/md/dev-${devname}/state done }

echo md0 > /sys/module/mdmod/parameters/newarray || die "create md0 failed"

addbysysfs & pid="$pid $!"

removebysysfs & pid="$pid $!"

sleep $runtime exit 0

Test cmd:

./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime

Test result:

general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bcb: 0000 [#4] PREEMPT SMP CPU: 0 PID: 1292 Comm: test Tainted: G D W 6.5.0-rc2-00121-g01e55c376936 #562 RIP: 0010:mdwakeupthread+0x9e/0x320 [mdmod] Call Trace: <TASK> mddevunlock+0x1b6/0x310 [mdmod] rdevattrstore+0xec/0x190 [mdmod] sysfskfwrite+0x52/0x70 kernfsfopwriteiter+0x19a/0x2a0 vfswrite+0x3b5/0x770 ksyswrite+0x74/0x150 _x64syswrite+0x22/0x30 dosyscall64+0x40/0x90 entrySYSCALL64afterhwframe+0x63/0xcd

Fix this problem by don't dereference mddev after export_rdev().

Database specific

{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53665.json",
    "cna_assigner": "Linux"
}

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: Introduced

3ce94ce5d05ae89190a23f6187f64d8f4b2d3782

Fixed

ad430ad0669d2757377373390d68e1454fc7a344

Fixed

7deac114be5fb25a4e865212ed0feaf5f85f2a28

Affected versions

v6.*

v6.4

v6.4-rc3

v6.4-rc4

v6.4-rc5

v6.4-rc6

v6.4-rc7

v6.5

v6.5-rc1

v6.5-rc2

v6.5-rc3

v6.5-rc4

v6.5-rc5

v6.5-rc6

v6.5-rc7

v6.5.1

v6.5.2

v6.5.3

v6.5.4

Database specific

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-53665.json"

vanir_signatures

[
    {
        "source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@ad430ad0669d2757377373390d68e1454fc7a344",
        "signature_type": "Line",
        "digest": {
            "line_hashes": [
                "144584885617495509648785784660420203871",
                "252906130527642134322606099364035298926",
                "71656540064801524008852764464308163032",
                "153563116538690863009898030407879836848",
                "298703790911235061980563662629725151460",
                "83733569671303354426566063658484429389",
                "213808633490132001701739464022435822188",
                "16575422887545803323601083756271551072",
                "324039834279588800905646018247402267682",
                "260783368088836480787798969868091827900"
            ],
            "threshold": 0.9
        },
        "deprecated": false,
        "target": {
            "file": "drivers/md/md.c"
        },
        "id": "CVE-2023-53665-1219494f",
        "signature_version": "v1"
    },
    {
        "source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@7deac114be5fb25a4e865212ed0feaf5f85f2a28",
        "signature_type": "Function",
        "digest": {
            "function_hash": "41691973522706903496236977035022284",
            "length": 1164.0
        },
        "deprecated": false,
        "target": {
            "file": "drivers/md/md.c",
            "function": "mddev_unlock"
        },
        "id": "CVE-2023-53665-13a69691",
        "signature_version": "v1"
    },
    {
        "source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@7deac114be5fb25a4e865212ed0feaf5f85f2a28",
        "signature_type": "Line",
        "digest": {
            "line_hashes": [
                "144584885617495509648785784660420203871",
                "252906130527642134322606099364035298926",
                "71656540064801524008852764464308163032",
                "153563116538690863009898030407879836848",
                "298703790911235061980563662629725151460",
                "83733569671303354426566063658484429389",
                "213808633490132001701739464022435822188",
                "16575422887545803323601083756271551072",
                "324039834279588800905646018247402267682",
                "260783368088836480787798969868091827900"
            ],
            "threshold": 0.9
        },
        "deprecated": false,
        "target": {
            "file": "drivers/md/md.c"
        },
        "id": "CVE-2023-53665-2a4e2c51",
        "signature_version": "v1"
    },
    {
        "source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@ad430ad0669d2757377373390d68e1454fc7a344",
        "signature_type": "Function",
        "digest": {
            "function_hash": "41691973522706903496236977035022284",
            "length": 1164.0
        },
        "deprecated": false,
        "target": {
            "file": "drivers/md/md.c",
            "function": "mddev_unlock"
        },
        "id": "CVE-2023-53665-9c9fbff4",
        "signature_version": "v1"
    }
]

Git / github.com/gregkh/linux