fkie_cve-2021-47375
Vulnerability from fkie_nvd
Published
2024-05-21 15:15
Modified
2024-11-21 06:36
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
blktrace: Fix uaf in blk_trace access after removing by sysfs
There is an use-after-free problem triggered by following process:
P1(sda) P2(sdb)
echo 0 > /sys/block/sdb/trace/enable
blk_trace_remove_queue
synchronize_rcu
blk_trace_free
relay_close
rcu_read_lock
__blk_add_trace
trace_note_tsk
(Iterate running_trace_list)
relay_close_buf
relay_destroy_buf
kfree(buf)
trace_note(sdb's bt)
relay_reserve
buf->offset <- nullptr deference (use-after-free) !!!
rcu_read_unlock
[ 502.714379] BUG: kernel NULL pointer dereference, address:
0000000000000010
[ 502.715260] #PF: supervisor read access in kernel mode
[ 502.715903] #PF: error_code(0x0000) - not-present page
[ 502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0
[ 502.717252] Oops: 0000 [#1] SMP
[ 502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360
[ 502.732872] Call Trace:
[ 502.733193] __blk_add_trace.cold+0x137/0x1a3
[ 502.733734] blk_add_trace_rq+0x7b/0xd0
[ 502.734207] blk_add_trace_rq_issue+0x54/0xa0
[ 502.734755] blk_mq_start_request+0xde/0x1b0
[ 502.735287] scsi_queue_rq+0x528/0x1140
...
[ 502.742704] sg_new_write.isra.0+0x16e/0x3e0
[ 502.747501] sg_ioctl+0x466/0x1100
Reproduce method:
ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
ioctl(/dev/sda, BLKTRACESTART)
ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
ioctl(/dev/sdb, BLKTRACESTART)
echo 0 > /sys/block/sdb/trace/enable &
// Add delay(mdelay/msleep) before kernel enters blk_trace_free()
ioctl$SG_IO(/dev/sda, SG_IO, ...)
// Enters trace_note_tsk() after blk_trace_free() returned
// Use mdelay in rcu region rather than msleep(which may schedule out)
Remove blk_trace from running_list before calling blk_trace_free() by
sysfs if blk_trace is at Blktrace_running state.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblktrace: Fix uaf in blk_trace access after removing by sysfs\n\nThere is an use-after-free problem triggered by following process:\n\n P1(sda)\t\t\t\tP2(sdb)\n\t\t\techo 0 \u003e /sys/block/sdb/trace/enable\n\t\t\t blk_trace_remove_queue\n\t\t\t synchronize_rcu\n\t\t\t blk_trace_free\n\t\t\t relay_close\nrcu_read_lock\n__blk_add_trace\n trace_note_tsk\n (Iterate running_trace_list)\n\t\t\t relay_close_buf\n\t\t\t\t relay_destroy_buf\n\t\t\t\t kfree(buf)\n trace_note(sdb\u0027s bt)\n relay_reserve\n buf-\u003eoffset \u003c- nullptr deference (use-after-free) !!!\nrcu_read_unlock\n\n[ 502.714379] BUG: kernel NULL pointer dereference, address:\n0000000000000010\n[ 502.715260] #PF: supervisor read access in kernel mode\n[ 502.715903] #PF: error_code(0x0000) - not-present page\n[ 502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0\n[ 502.717252] Oops: 0000 [#1] SMP\n[ 502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360\n[ 502.732872] Call Trace:\n[ 502.733193] __blk_add_trace.cold+0x137/0x1a3\n[ 502.733734] blk_add_trace_rq+0x7b/0xd0\n[ 502.734207] blk_add_trace_rq_issue+0x54/0xa0\n[ 502.734755] blk_mq_start_request+0xde/0x1b0\n[ 502.735287] scsi_queue_rq+0x528/0x1140\n...\n[ 502.742704] sg_new_write.isra.0+0x16e/0x3e0\n[ 502.747501] sg_ioctl+0x466/0x1100\n\nReproduce method:\n ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])\n ioctl(/dev/sda, BLKTRACESTART)\n ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])\n ioctl(/dev/sdb, BLKTRACESTART)\n\n echo 0 \u003e /sys/block/sdb/trace/enable \u0026\n // Add delay(mdelay/msleep) before kernel enters blk_trace_free()\n\n ioctl$SG_IO(/dev/sda, SG_IO, ...)\n // Enters trace_note_tsk() after blk_trace_free() returned\n // Use mdelay in rcu region rather than msleep(which may schedule out)\n\nRemove blk_trace from running_list before calling blk_trace_free() by\nsysfs if blk_trace is at Blktrace_running state."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: blktrace: corrige uaf en el acceso a blk_trace despu\u00e9s de eliminarlo mediante sysfs. Hay un problema de use after free desencadenado por el siguiente proceso: P1(sda) P2(sdb) echo 0 \u0026gt; /sys /block/sdb/trace/enable blk_trace_remove_queue sincronizar_rcu blk_trace_free rel\u00e9_cerrar rcu_read_lock __blk_add_trace trace_note_tsk (Iterar running_trace_list) rel\u00e9_close_buf rel\u00e9_destroy_buf kfree(buf) trace_note(sdb\u0027s bt) rel\u00e9_reserve buf-\u0026gt;offset \u0026lt;- deferencia nullptr (uso-despu\u00e9s) -gratis) !!! rcu_read_unlock [502.714379] ERROR: desreferencia del puntero NULL del kernel, direcci\u00f3n: 0000000000000010 [502.715260] #PF: acceso de lectura de supervisor en modo kernel [502.715903] #PF: error_code(0x0000) - p\u00e1gina no presente [502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0 [ 502.717252] Vaya: 0000 [#1] SMP [ 502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360 [ 502.732872] Seguimiento de llamadas: [ 502.733193] 0x1a3 [502.733734] blk_add_trace_rq+ 0x7b/0xd0 [ 502.734207] blk_add_trace_rq_issue+0x54/0xa0 [ 502.734755] blk_mq_start_request+0xde/0x1b0 [ 502.735287] scsi_queue_rq+0x528/0x1140 ... [ 502.7427 04] sg_new_write.isra.0+0x16e/0x3e0 [ 502.747501] sg_ioctl+0x466/0x1100 M\u00e9todo de reproducci\u00f3n: ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sda, BLKTRACESTART) ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sdb , BLKTRACESTART) echo 0 \u0026gt; /sys/block/sdb/trace/enable \u0026amp; // Agrega retraso(mdelay/msleep) antes de que el kernel entre blk_trace_free() ioctl$SG_IO(/dev/sda, SG_IO, ...) // Entra trace_note_tsk() despu\u00e9s de que blk_trace_free() regresara // Utilice mdelay en la regi\u00f3n rcu en lugar de msleep (que puede programarse) Elimine blk_trace de running_list antes de llamar a blk_trace_free() mediante sysfs si blk_trace est\u00e1 en el estado Blktrace_running."
}
],
"id": "CVE-2021-47375",
"lastModified": "2024-11-21T06:36:00.920",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "NONE",
"baseScore": 6.2,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"version": "3.1"
},
"exploitabilityScore": 2.5,
"impactScore": 3.6,
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
]
},
"published": "2024-05-21T15:15:23.290",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/3815fe7371d2411ce164281cef40d9fc7b323dee"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/488da313edf3abea7f7733efe011c96b23740ab5"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/5afedf670caf30a2b5a52da96eb7eac7dee6a9c9"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/677e362ba807f3aafe6f405c07e0b37244da5222"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/a5f8e86192612d0183047448d8bbe7918b3f1a26"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/d56171d9360c0170c5c5f8f7e2362a2e999eca40"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/dacfd5e4d1142bfb3809aab3634a375f6f373269"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"url": "https://git.kernel.org/stable/c/ebb8d26d93c3ec3c7576c52a8373a2309423c069"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-416"
}
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary"
}
]
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.