CVE-2024-26615 net/smc: fix illegal rmb_desc access in SMC-D connection dump

2024-02-2915:52:18

Linux

www.cve.org

vulnerability resolved

smc-d connection

crash issue

nginx/wrk test

kernel null pointer dereference

connection close

smc-d connections dump

link group

smc_conn_create()

rmb_desc

smc_buf_create()

illegal access

cve-2024-26615

7.5 High

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

13.1%

JSON

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

net/smc: fix illegal rmb_desc access in SMC-D connection dump

A crash was found when dumping SMC-D connections. It can be reproduced
by following steps:

run nginx/wrk test:
smc_run nginx
smc_run wrk -t 16 -c 1000 -d <duration> -H ‘Connection: Close’ <URL>
continuously dump SMC-D connections in parallel:
watch -n 1 ‘smcss -D’

BUG: kernel NULL pointer dereference, address: 0000000000000030
CPU: 2 PID: 7204 Comm: smcss Kdump: loaded Tainted: G E 6.7.0+ #55
RIP: 0010:__smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag]
Call Trace:
<TASK>
? __die+0x24/0x70
? page_fault_oops+0x66/0x150
? exc_page_fault+0x69/0x140
? asm_exc_page_fault+0x26/0x30
? __smc_diag_dump.constprop.0+0x5e5/0x620 [smc_diag]
? __kmalloc_node_track_caller+0x35d/0x430
? __alloc_skb+0x77/0x170
smc_diag_dump_proto+0xd0/0xf0 [smc_diag]
smc_diag_dump+0x26/0x60 [smc_diag]
netlink_dump+0x19f/0x320
__netlink_dump_start+0x1dc/0x300
smc_diag_handler_dump+0x6a/0x80 [smc_diag]
? __pfx_smc_diag_dump+0x10/0x10 [smc_diag]
sock_diag_rcv_msg+0x121/0x140
? __pfx_sock_diag_rcv_msg+0x10/0x10
netlink_rcv_skb+0x5a/0x110
sock_diag_rcv+0x28/0x40
netlink_unicast+0x22a/0x330
netlink_sendmsg+0x1f8/0x420
__sock_sendmsg+0xb0/0xc0
____sys_sendmsg+0x24e/0x300
? copy_msghdr_from_user+0x62/0x80
___sys_sendmsg+0x7c/0xd0
? __do_fault+0x34/0x160
? do_read_fault+0x5f/0x100
? do_fault+0xb0/0x110
? __handle_mm_fault+0x2b0/0x6c0
__sys_sendmsg+0x4d/0x80
do_syscall_64+0x69/0x180
entry_SYSCALL_64_after_hwframe+0x6e/0x76

It is possible that the connection is in process of being established
when we dump it. Assumed that the connection has been registered in a
link group by smc_conn_create() but the rmb_desc has not yet been
initialized by smc_buf_create(), thus causing the illegal access to
conn->rmb_desc. So fix it by checking before dump.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/smc/smc_diag.c"
    ],
    "versions": [
      {
        "version": "4b1b7d3b30a6",
        "lessThan": "27aea6483891",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "4b1b7d3b30a6",
        "lessThan": "1fea9969b81c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "4b1b7d3b30a6",
        "lessThan": "5fed92ca32ea",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "4b1b7d3b30a6",
        "lessThan": "68b888d51ac8",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "4b1b7d3b30a6",
        "lessThan": "6994dba06321",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "4b1b7d3b30a6",
        "lessThan": "a164c2922675",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "4b1b7d3b30a6",
        "lessThan": "8f3f9186e5bb",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "4b1b7d3b30a6",
        "lessThan": "dbc153fd3c14",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/smc/smc_diag.c"
    ],
    "versions": [
      {
        "version": "4.19",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "4.19",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.307",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.269",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.210",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.149",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.76",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.15",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.7.3",
        "lessThanOrEqual": "6.7.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]