CVE-2024-27399 Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout

2024-05-1310:24:57

Linux

www.cve.org

bluetooth

vulnerability

fix

null-ptr-deref

race condition

linux kernel

kasan report

poc

mutex_lock

kernel taint

6.3 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

13.1%

JSON

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

Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout

There is a race condition between l2cap_chan_timeout() and
l2cap_chan_del(). When we use l2cap_chan_del() to delete the
channel, the chan->conn will be set to null. But the conn could
be dereferenced again in the mutex_lock() of l2cap_chan_timeout().
As a result the null pointer dereference bug will happen. The
KASAN report triggered by POC is shown below:

[ 472.074580] ==================================================================
[ 472.075284] BUG: KASAN: null-ptr-deref in mutex_lock+0x68/0xc0
[ 472.075308] Write of size 8 at addr 0000000000000158 by task kworker/0:0/7
[ 472.075308]
[ 472.075308] CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.9.0-rc5-00356-g78c0094a146b #36
[ 472.075308] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4
[ 472.075308] Workqueue: events l2cap_chan_timeout
[ 472.075308] Call Trace:
[ 472.075308] <TASK>
[ 472.075308] dump_stack_lvl+0x137/0x1a0
[ 472.075308] print_report+0x101/0x250
[ 472.075308] ? __virt_addr_valid+0x77/0x160
[ 472.075308] ? mutex_lock+0x68/0xc0
[ 472.075308] kasan_report+0x139/0x170
[ 472.075308] ? mutex_lock+0x68/0xc0
[ 472.075308] kasan_check_range+0x2c3/0x2e0
[ 472.075308] mutex_lock+0x68/0xc0
[ 472.075308] l2cap_chan_timeout+0x181/0x300
[ 472.075308] process_one_work+0x5d2/0xe00
[ 472.075308] worker_thread+0xe1d/0x1660
[ 472.075308] ? pr_cont_work+0x5e0/0x5e0
[ 472.075308] kthread+0x2b7/0x350
[ 472.075308] ? pr_cont_work+0x5e0/0x5e0
[ 472.075308] ? kthread_blkcg+0xd0/0xd0
[ 472.075308] ret_from_fork+0x4d/0x80
[ 472.075308] ? kthread_blkcg+0xd0/0xd0
[ 472.075308] ret_from_fork_asm+0x11/0x20
[ 472.075308] </TASK>
[ 472.075308] ==================================================================
[ 472.094860] Disabling lock debugging due to kernel taint
[ 472.096136] BUG: kernel NULL pointer dereference, address: 0000000000000158
[ 472.096136] #PF: supervisor write access in kernel mode
[ 472.096136] #PF: error_code(0x0002) - not-present page
[ 472.096136] PGD 0 P4D 0
[ 472.096136] Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI
[ 472.096136] CPU: 0 PID: 7 Comm: kworker/0:0 Tainted: G B 6.9.0-rc5-00356-g78c0094a146b #36
[ 472.096136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4
[ 472.096136] Workqueue: events l2cap_chan_timeout
[ 472.096136] RIP: 0010:mutex_lock+0x88/0xc0
[ 472.096136] Code: be 08 00 00 00 e8 f8 23 1f fd 4c 89 f7 be 08 00 00 00 e8 eb 23 1f fd 42 80 3c 23 00 74 08 48 88
[ 472.096136] RSP: 0018:ffff88800744fc78 EFLAGS: 00000246
[ 472.096136] RAX: 0000000000000000 RBX: 1ffff11000e89f8f RCX: ffffffff8457c865
[ 472.096136] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88800744fc78
[ 472.096136] RBP: 0000000000000158 R08: ffff88800744fc7f R09: 1ffff11000e89f8f
[ 472.096136] R10: dffffc0000000000 R11: ffffed1000e89f90 R12: dffffc0000000000
[ 472.096136] R13: 0000000000000158 R14: ffff88800744fc78 R15: ffff888007405a00
[ 472.096136] FS: 0000000000000000(0000) GS:ffff88806d200000(0000) knlGS:0000000000000000
[ 472.096136] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 472.096136] CR2: 0000000000000158 CR3: 000000000da32000 CR4: 00000000000006f0
[ 472.096136] Call Trace:
[ 472.096136] <TASK>
[ 472.096136] ? __die_body+0x8d/0xe0
[ 472.096136] ? page_fault_oops+0x6b8/0x9a0
[ 472.096136] ? kernelmode_fixup_or_oops+0x20c/0x2a0
[ 472.096136] ? do_user_addr_fault+0x1027/0x1340
[ 472.096136] ? _printk+0x7a/0xa0
[ 472.096136] ? mutex_lock+0x68/0xc0
[ 472.096136] ? add_taint+0x42/0xd0
[ 472.096136] ? exc_page_fault+0x6a/0x1b0
[ 472.096136] ? asm_exc_page_fault+0x26/0x30
[ 472.096136] ? mutex_lock+0x75/0xc0
[ 472.096136] ? mutex_lock+0x88/0xc0
[ 472.096136] ? mutex_lock+0x75/0xc0
[ 472.096136] l2cap_chan_timeo
—truncated—

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/bluetooth/l2cap_core.c"
    ],
    "versions": [
      {
        "version": "3df91ea20e74",
        "lessThan": "e137e2ba96e5",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3df91ea20e74",
        "lessThan": "6466ee65e5b2",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3df91ea20e74",
        "lessThan": "06acb75e7ed6",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3df91ea20e74",
        "lessThan": "e97e16433eb4",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3df91ea20e74",
        "lessThan": "8960ff650aec",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3df91ea20e74",
        "lessThan": "955b5b6c54d9",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3df91ea20e74",
        "lessThan": "eb86f955488c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "3df91ea20e74",
        "lessThan": "adf0398cee86",
        "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/bluetooth/l2cap_core.c"
    ],
    "versions": [
      {
        "version": "3.4",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "3.4",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.314",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.276",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.217",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.159",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.91",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.31",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8.10",
        "lessThanOrEqual": "6.8.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]