CVE-2024-26645

tracing: Ensure visibility when inserting an element into tracing_map

Severity Score

4.4

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

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

tracing: Ensure visibility when inserting an element into tracing_map

Running the following two commands in parallel on a multi-processor
AArch64 machine can sporadically produce an unexpected warning about
duplicate histogram entries:

$ while true; do
echo hist:key=id.syscall:val=hitcount > \n /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
sleep 0.001
done
$ stress-ng --sysbadaddr $(nproc)

The warning looks as follows:

[ 2911.172474] ------------[ cut here ]------------
[ 2911.173111] Duplicates detected: 1
[ 2911.173574] WARNING: CPU: 2 PID: 12247 at kernel/trace/tracing_map.c:983 tracing_map_sort_entries+0x3e0/0x408
[ 2911.174702] Modules linked in: iscsi_ibft(E) iscsi_boot_sysfs(E) rfkill(E) af_packet(E) nls_iso8859_1(E) nls_cp437(E) vfat(E) fat(E) ena(E) tiny_power_button(E) qemu_fw_cfg(E) button(E) fuse(E) efi_pstore(E) ip_tables(E) x_tables(E) xfs(E) libcrc32c(E) aes_ce_blk(E) aes_ce_cipher(E) crct10dif_ce(E) polyval_ce(E) polyval_generic(E) ghash_ce(E) gf128mul(E) sm4_ce_gcm(E) sm4_ce_ccm(E) sm4_ce(E) sm4_ce_cipher(E) sm4(E) sm3_ce(E) sm3(E) sha3_ce(E) sha512_ce(E) sha512_arm64(E) sha2_ce(E) sha256_arm64(E) nvme(E) sha1_ce(E) nvme_core(E) nvme_auth(E) t10_pi(E) sg(E) scsi_mod(E) scsi_common(E) efivarfs(E)
[ 2911.174738] Unloaded tainted modules: cppc_cpufreq(E):1
[ 2911.180985] CPU: 2 PID: 12247 Comm: cat Kdump: loaded Tainted: G E 6.7.0-default #2 1b58bbb22c97e4399dc09f92d309344f69c44a01
[ 2911.182398] Hardware name: Amazon EC2 c7g.8xlarge/, BIOS 1.0 11/1/2018
[ 2911.183208] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[ 2911.184038] pc : tracing_map_sort_entries+0x3e0/0x408
[ 2911.184667] lr : tracing_map_sort_entries+0x3e0/0x408
[ 2911.185310] sp : ffff8000a1513900
[ 2911.185750] x29: ffff8000a1513900 x28: ffff0003f272fe80 x27: 0000000000000001
[ 2911.186600] x26: ffff0003f272fe80 x25: 0000000000000030 x24: 0000000000000008
[ 2911.187458] x23: ffff0003c5788000 x22: ffff0003c16710c8 x21: ffff80008017f180
[ 2911.188310] x20: ffff80008017f000 x19: ffff80008017f180 x18: ffffffffffffffff
[ 2911.189160] x17: 0000000000000000 x16: 0000000000000000 x15: ffff8000a15134b8
[ 2911.190015] x14: 0000000000000000 x13: 205d373432323154 x12: 5b5d313131333731
[ 2911.190844] x11: 00000000fffeffff x10: 00000000fffeffff x9 : ffffd1b78274a13c
[ 2911.191716] x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 000000000057ffa8
[ 2911.192554] x5 : ffff0012f6c24ec0 x4 : 0000000000000000 x3 : ffff2e5b72b5d000
[ 2911.193404] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0003ff254480
[ 2911.194259] Call trace:
[ 2911.194626] tracing_map_sort_entries+0x3e0/0x408
[ 2911.195220] hist_show+0x124/0x800
[ 2911.195692] seq_read_iter+0x1d4/0x4e8
[ 2911.196193] seq_read+0xe8/0x138
[ 2911.196638] vfs_read+0xc8/0x300
[ 2911.197078] ksys_read+0x70/0x108
[ 2911.197534] __arm64_sys_read+0x24/0x38
[ 2911.198046] invoke_syscall+0x78/0x108
[ 2911.198553] el0_svc_common.constprop.0+0xd0/0xf8
[ 2911.199157] do_el0_svc+0x28/0x40
[ 2911.199613] el0_svc+0x40/0x178
[ 2911.200048] el0t_64_sync_handler+0x13c/0x158
[ 2911.200621] el0t_64_sync+0x1a8/0x1b0
[ 2911.201115] ---[ end trace 0000000000000000 ]---

The problem appears to be caused by CPU reordering of writes issued from
__tracing_map_insert().

The check for the presence of an element with a given key in this
function is:

val = READ_ONCE(entry->val);
if (val && keys_match(key, val->key, map->key_size)) ...

The write of a new entry is:

elt = get_free_elt(map);
memcpy(elt->key, key, map->key_size);
entry->val = elt;

The "memcpy(elt->key, key, map->key_size);" and "entry->val = elt;"
stores may become visible in the reversed order on another CPU. This
second CPU might then incorrectly determine that a new key doesn't match
an already present val->key and subse
---truncated---

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: rastreo: garantiza la visibilidad al insertar un elemento en tracing_map La ejecución de los siguientes dos comandos en paralelo en una máquina multiprocesador AArch64 puede producir esporádicamente una advertencia inesperada sobre entradas de histograma duplicadas: $ while true ; hacer echo hist:key=id.syscall:val=hitcount > \ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist sleep 0.001 done $ estrés-ng --sysbadaddr $(nproc) La advertencia tiene el siguiente aspecto: [ 2911.172474] ------------[ cortar aquí ]------------ [ 2911.173111] Duplicados detectados: 1 [2911.173574] ADVERTENCIA: CPU: 2 PID: 12247 en kernel/trace/tracing_map.c:983 tracing_map_sort_entries+0x3e0/0x408 [2911.174702] Módulos vinculados en: iscsi_ibft(E) iscsi_boot_sy sfs(E) rfkill(E ) af_packet(E) nls_iso8859_1(E) nls_cp437(E) vfat(E) fat(E) ena(E) tiny_power_button(E) qemu_fw_cfg(E) botón(E) fusible(E) efi_pstore(E) ip_tables(E) x_tables (E) xfs(E) libcrc32c(E) aes_ce_blk(E) aes_ce_cipher(E) crct10dif_ce(E) polyval_ce(E) polyval_generic(E) ghash_ce(E) gf128mul(E) sm4_ce_gcm(E) sm4_ce_ccm(E) sm4_ce(E ) sm4_ce_cipher(E) sm4(E) sm3_ce(E) sm3(E) sha3_ce(E) sha512_ce(E) sha512_arm64(E) sha2_ce(E) sha256_arm64(E) nvme(E) sha1_ce(E) nvme_core(E) nvme_auth (E) t10_pi(E) sg(E) scsi_mod(E) scsi_common(E) efivarfs(E) [ 2911.174738] Módulos contaminados descargados: cppc_cpufreq(E):1 [ 2911.180985] CPU: 2 PID: 12247 Comm: cat Kdump: cargado Contaminado: GE 6.7.0-default #2 1b58bbb22c97e4399dc09f92d309344f69c44a01 [2911.182398] Nombre de hardware: Amazon EC2 c7g.8xlarge/, BIOS 1.0 1/11/2018 [2911.183208] pstate: 6140 0005 (nZCv daif +PAN -UAO -TCO +DIT - SSBS BTYPE=--) [ 2911.184038] pc : tracing_map_sort_entries+0x3e0/0x408 [ 2911.184667] lr : tracing_map_sort_entries+0x3e0/0x408 [ 2911.185310] sp : ffff8000a1513900 [ 2911.18 5750] x29: ffff8000a1513900 x28: ffff0003f272fe80 x27: 0000000000000001 [ 2911.186600] x26: ffff0003f272fe80 x25: 0000000000000030 x24: 00000000000000008 [ 2911.187458] x23: ffff0003c5788000 x22: ffff0003c16710c8 x21: ffff80008017f180 [ 2911.1883 10] x20: ffff80008017f000 x19: ffff80008017f180 x18: ffffffffffffffff [ 2911.189160] x17: 0000000000000000 x16: 0000000000000000 x15: ffff8000a151 34b8 [2911.190015] x14: 0000000000000000 x13: 205d373432323154 x12: 5b5d313131333731 [ 2911.190844] x11: 00000000fffeffff x10: 00000000fffeffff x9 : ffffd1b78274a13c [ 2911.191716] x8 : 00 0000000017ffe8 x7: c0000000fffeffff x6: 000000000057ffa8 [2911.192554] x5: ffff0012f6c24ec0 x4: 00000000000000000 x3: ffff2e5b72b5d000 [2911.193 404] x2: 0000000000000000 x1: 0000000000000000 x0 : ffff0003ff254480 [2911.194259] Rastreo de llamadas: [2911.194626] tracing_map_sort_entries+0x3e0/0x408 [2911.195220] hist_show+0x124/0x800 [2911.195692] seq_read_iter+0x1d4 /0x4e8 [ 2911.196193] seq_read+0xe8/0x138 [ 2911.196638] vfs_read+0xc8/0x300 [ 2911.197078 ] ksys_read+0x70/0x108 [ 2911.197534] __arm64_sys_read+0x24/0x38 [ 2911.198046] invoke_syscall+0x78/0x108 [ 2911.198553] el0_svc_common.constprop.0+0xd0/0x f8 [ 2911.199157] do_el0_svc+0x28/0x40 [ 2911.199613] el0_svc+0x40/0x178 [ 2911.200048] el0t_64_sync_handler+0x13c/0x158 [ 2911.200621] el0t_64_sync+0x1a8/0x1b0 [ 2911.201115] ---[ end trace 0000000000000000 ]--- El problema parece deberse a la reordenación de la CPU de escrituras emitidas desde __tracing_map_insert(). La comprobación de la presencia de un elemento con una clave determinada en esta función es: val = READ_ONCE(entry->val); if (val && llaves_match(key, val->key, map->key_size)) ... La escritura de una nueva entrada es: elt = get_free_elt(map); memcpy(elt->clave, clave, mapa->key_size); entrada->val = elt; El "memcpy(elt->key, key, map->key_size);" y "entrada->val = elt;" Las tiendas pueden volverse visibles en orden inverso en otra CPU.---truncada---

*Credits: N/A

CVSS Scores

Red Hatv3.1 4.4

Attack Vector

Local

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-02-19 CVE Reserved
2024-03-26 CVE Published
2024-03-27 EPSS Updated
2024-08-02 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CAPEC

References (13)

URL	Tag	Source
https://git.kernel.org/stable/c/c193707dde77ace92a649cd59a17e105e2fbeaef	Vuln. Introduced
https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/5022b331c041e8c54b9a6a3251579bd1e8c0fc0b	2024-02-23
https://git.kernel.org/stable/c/dad9b28f675ed99b4dec261db2a397efeb80b74c	2024-02-23
https://git.kernel.org/stable/c/ef70dfa0b1e5084f32635156c9a5c795352ad860	2024-02-23
https://git.kernel.org/stable/c/aef1cb00856ccfd614467cfb50b791278992e177	2024-02-23
https://git.kernel.org/stable/c/f4f7e696db0274ff560482cc52eddbf0551d4b7a	2024-02-01
https://git.kernel.org/stable/c/a1eebe76e187dbe11ca299f8dbb6e45d5b1889e7	2024-02-01
https://git.kernel.org/stable/c/bf4aeff7da85c3becd39fb73bac94122331c30fb	2024-02-01
https://git.kernel.org/stable/c/2b44760609e9eaafc9d234a6883d042fc21132a7	2024-01-22

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2024-26645	2024-09-24
https://bugzilla.redhat.com/show_bug.cgi?id=2271648	2024-09-24

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.17 < 4.19.307 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.17 < 4.19.307"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.17 < 5.4.269 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.17 < 5.4.269"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.17 < 5.10.210 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.17 < 5.10.210"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.17 < 5.15.149 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.17 < 5.15.149"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.17 < 6.1.76 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.17 < 6.1.76"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.17 < 6.6.15 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.17 < 6.6.15"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.17 < 6.7.3 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.17 < 6.7.3"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.17 < 6.8 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.17 < 6.8"		en		Affected