{
  "cveId": "CVE-2022-49441",
  "url": "https://patchblox.com/security/cve/CVE-2022-49441",
  "summary": "CVE-2022-49441 is fixed in linux on 1 platform, first by DEBIAN-CVE-2022-49441, released February 26, 2025. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  tty: fix deadlock caused by calling printk() und...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  tty: fix deadlock caused by calling printk() under tty_port-\u003Elock  pty_write() invokes kmalloc() which may invoke a normal printk() to print failure message.  This can cause a deadlock in the scenario reported by syz-bot below:         CPU0              CPU1                    CPU2        ----              ----                    ----                          lock(console_owner);                                                  lock(\u0026port_lock_key);   lock(\u0026port-\u003Elock);                          lock(\u0026port_lock_key);                                                  lock(\u0026port-\u003Elock);   lock(console_owner);  As commit dbdda842fe96 (\u0022printk: Add console owner and waiter logic to load balance console writes\u0022) said, such deadlock can be prevented by using printk_deferred() in kmalloc() (which is invoked in the section guarded by the port-\u003Elock).  But there are too many printk() on the kmalloc() path, and kmalloc() can be called from anywhere, so changing printk() to printk_deferred() is too complicated and inelegant.  Therefore, this patch chooses to specify __GFP_NOWARN to kmalloc(), so that printk() will not be called, and this deadlock problem can be avoided.  Syzbot reported the following lockdep error:  ====================================================== WARNING: possible circular locking dependency detected 5.4.143-00237-g08ccc19a-dirty #10 Not tainted ------------------------------------------------------ syz-executor.4/29420 is trying to acquire lock: ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1752 [inline] ffffffff8aedb2a0 (console_owner){....}-{0:0}, at: vprintk_emit\u002B0x2ca/0x470 kernel/printk/printk.c:2023  but task is already holding lock: ffff8880119c9158 (\u0026port-\u003Elock){-.-.}-{2:2}, at: pty_write\u002B0xf4/0x1f0 drivers/tty/pty.c:120  which lock already depends on the new lock.  the existing dependency chain (in reverse order) is:  -\u003E #2 (\u0026port-\u003Elock){-.-.}-{2:2}:        __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]        _raw_spin_lock_irqsave\u002B0x35/0x50 kernel/locking/spinlock.c:159        tty_port_tty_get drivers/tty/tty_port.c:288 [inline]          \t\t\u003C-- lock(\u0026port-\u003Elock);        tty_port_default_wakeup\u002B0x1d/0xb0 drivers/tty/tty_port.c:47        serial8250_tx_chars\u002B0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767        serial8250_handle_irq.part.0\u002B0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854        serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] \t\u003C-- lock(\u0026port_lock_key);        serial8250_default_handle_irq\u002B0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870        serial8250_interrupt\u002B0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126        __handle_irq_event_percpu\u002B0x109/0xa50 kernel/irq/handle.c:156        [...]  -\u003E #1 (\u0026port_lock_key){-.-.}-{2:2}:        __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]        _raw_spin_lock_irqsave\u002B0x35/0x50 kernel/locking/spinlock.c:159        serial8250_console_write\u002B0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198 \t\t\t\t\t\t\t\t\t\t\u003C-- lock(\u0026port_lock_key);        call_console_drivers kernel/printk/printk.c:1819 [inline]        console_unlock\u002B0x8cb/0xd00 kernel/printk/printk.c:2504        vprintk_emit\u002B0x1b5/0x470 kernel/printk/printk.c:2024\t\t\t\u003C-- lock(console_owner);        vprintk_func\u002B0x8d/0x250 kernel/printk/printk_safe.c:394        printk\u002B0xba/0xed kernel/printk/printk.c:2084        register_console\u002B0x8b3/0xc10 kernel/printk/printk.c:2829        univ8250_console_init\u002B0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681        console_init\u002B0x49d/0x6d3 kernel/printk/printk.c:2915        start_kernel\u002B0x5e9/0x879 init/main.c:713        secondary_startup_64\u002B0xa4/0xb0 arch/x86/kernel/head_64.S:241  -\u003E #0 (console_owner){....}-{0:0}:        [...]        lock_acquire\u002B0x127/0x340 kernel/locking/lockdep.c:4734        console_trylock_spinning kernel/printk/printk.c:1773  ---truncated---",
  "published": "2025-02-26T07:01:20Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00236,
  "epssPercentile": 0.14732,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.18.5-1",
      "fix": "DEBIAN-CVE-2022-49441",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2022-49441",
      "released": "2025-02-26T07:01:20Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.18.5-1",
      "fix": "DEBIAN-CVE-2022-49441",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2022-49441",
      "released": "2025-02-26T07:01:20Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "5.18.5-1",
      "fix": "DEBIAN-CVE-2022-49441",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2022-49441",
      "released": "2025-02-26T07:01:20Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}