fkie_cve-2022-49441
Vulnerability from fkie_nvd
Published
2025-02-26 07:01
Modified
2025-03-17 16:53
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
tty: fix deadlock caused by calling printk() under tty_port->lock
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(&port_lock_key);
lock(&port->lock);
lock(&port_lock_key);
lock(&port->lock);
lock(console_owner);
As commit dbdda842fe96 ("printk: Add console owner and waiter logic to
load balance console writes") said, such deadlock can be prevented by
using printk_deferred() in kmalloc() (which is invoked in the section
guarded by the port->lock). 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+0x2ca/0x470 kernel/printk/printk.c:2023
but task is already holding lock:
ffff8880119c9158 (&port->lock){-.-.}-{2:2}, at: pty_write+0xf4/0x1f0 drivers/tty/pty.c:120
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&port->lock){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159
tty_port_tty_get drivers/tty/tty_port.c:288 [inline] <-- lock(&port->lock);
tty_port_default_wakeup+0x1d/0xb0 drivers/tty/tty_port.c:47
serial8250_tx_chars+0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767
serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] <-- lock(&port_lock_key);
serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870
serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126
__handle_irq_event_percpu+0x109/0xa50 kernel/irq/handle.c:156
[...]
-> #1 (&port_lock_key){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159
serial8250_console_write+0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198
<-- lock(&port_lock_key);
call_console_drivers kernel/printk/printk.c:1819 [inline]
console_unlock+0x8cb/0xd00 kernel/printk/printk.c:2504
vprintk_emit+0x1b5/0x470 kernel/printk/printk.c:2024 <-- lock(console_owner);
vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394
printk+0xba/0xed kernel/printk/printk.c:2084
register_console+0x8b3/0xc10 kernel/printk/printk.c:2829
univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681
console_init+0x49d/0x6d3 kernel/printk/printk.c:2915
start_kernel+0x5e9/0x879 init/main.c:713
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241
-> #0 (console_owner){....}-{0:0}:
[...]
lock_acquire+0x127/0x340 kernel/locking/lockdep.c:4734
console_trylock_spinning kernel/printk/printk.c:1773
---truncated---
References
Impacted products
Vendor | Product | Version | |
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linux | linux_kernel | * | |
linux | linux_kernel | * | |
linux | linux_kernel | * | |
linux | linux_kernel | * | |
linux | linux_kernel | * | |
linux | linux_kernel | * | |
linux | linux_kernel | * | |
linux | linux_kernel | * | |
linux | linux_kernel | * | |
linux | linux_kernel | * |
{ "configurations": [ { "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "3E38B3B3-C9B4-4F8E-B27F-E121FA35D422", "versionEndExcluding": "3.19", "versionStartIncluding": "3.18.118", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "9F7ABD11-7E25-4617-AD4B-2068A90C7EF8", "versionEndExcluding": "4.5", "versionStartIncluding": "4.4.146", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "FF4DA68C-0A82-4061-AEA7-59632762D9E2", "versionEndExcluding": "4.9.318", "versionStartIncluding": "4.9.117", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "378D8F4C-4F16-4488-9872-625DEA9B337A", "versionEndExcluding": "4.14.283", "versionStartIncluding": "4.14.60", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "A0236C89-21F4-4889-AA04-D7985FBBD23F", "versionEndExcluding": "4.19.247", "versionStartIncluding": "4.17.12", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "3EC49633-14DE-4EBD-BB80-76AE2E3EABB9", "versionEndExcluding": "5.4.198", "versionStartIncluding": "4.20", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "34ACD872-E5BC-401C-93D5-B357A62426E0", "versionEndExcluding": "5.10.121", "versionStartIncluding": "5.5", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "20D41697-0E8B-4B7D-8842-F17BF2AA21E1", "versionEndExcluding": "5.15.46", "versionStartIncluding": "5.11", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "15E2DD33-2255-4B76-9C15-04FF8CBAB252", "versionEndExcluding": "5.17.14", "versionStartIncluding": "5.16", "vulnerable": true }, { "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "8E122216-2E9E-4B3E-B7B8-D575A45BA3C2", "versionEndExcluding": "5.18.3", "versionStartIncluding": "5.18", "vulnerable": true } ], "negate": false, "operator": "OR" } ] } ], "cveTags": [], "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: fix deadlock caused by calling printk() under tty_port-\u003elock\n\npty_write() invokes kmalloc() which may invoke a normal printk() to print\nfailure message. This can cause a deadlock in the scenario reported by\nsyz-bot below:\n\n CPU0 CPU1 CPU2\n ---- ---- ----\n lock(console_owner);\n lock(\u0026port_lock_key);\n lock(\u0026port-\u003elock);\n lock(\u0026port_lock_key);\n lock(\u0026port-\u003elock);\n lock(console_owner);\n\nAs commit dbdda842fe96 (\"printk: Add console owner and waiter logic to\nload balance console writes\") said, such deadlock can be prevented by\nusing printk_deferred() in kmalloc() (which is invoked in the section\nguarded by the port-\u003elock). But there are too many printk() on the\nkmalloc() path, and kmalloc() can be called from anywhere, so changing\nprintk() to printk_deferred() is too complicated and inelegant.\n\nTherefore, this patch chooses to specify __GFP_NOWARN to kmalloc(), so\nthat printk() will not be called, and this deadlock problem can be\navoided.\n\nSyzbot reported the following lockdep error:\n\n======================================================\nWARNING: possible circular locking dependency detected\n5.4.143-00237-g08ccc19a-dirty #10 Not tainted\n------------------------------------------------------\nsyz-executor.4/29420 is trying to acquire lock:\nffffffff8aedb2a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1752 [inline]\nffffffff8aedb2a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x2ca/0x470 kernel/printk/printk.c:2023\n\nbut task is already holding lock:\nffff8880119c9158 (\u0026port-\u003elock){-.-.}-{2:2}, at: pty_write+0xf4/0x1f0 drivers/tty/pty.c:120\n\nwhich lock already depends on the new lock.\n\nthe existing dependency chain (in reverse order) is:\n\n-\u003e #2 (\u0026port-\u003elock){-.-.}-{2:2}:\n __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]\n _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159\n tty_port_tty_get drivers/tty/tty_port.c:288 [inline] \t\t\u003c-- lock(\u0026port-\u003elock);\n tty_port_default_wakeup+0x1d/0xb0 drivers/tty/tty_port.c:47\n serial8250_tx_chars+0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767\n serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854\n serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] \t\u003c-- lock(\u0026port_lock_key);\n serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870\n serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126\n __handle_irq_event_percpu+0x109/0xa50 kernel/irq/handle.c:156\n [...]\n\n-\u003e #1 (\u0026port_lock_key){-.-.}-{2:2}:\n __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]\n _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159\n serial8250_console_write+0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198\n\t\t\t\t\t\t\t\t\t\t\u003c-- lock(\u0026port_lock_key);\n call_console_drivers kernel/printk/printk.c:1819 [inline]\n console_unlock+0x8cb/0xd00 kernel/printk/printk.c:2504\n vprintk_emit+0x1b5/0x470 kernel/printk/printk.c:2024\t\t\t\u003c-- lock(console_owner);\n vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394\n printk+0xba/0xed kernel/printk/printk.c:2084\n register_console+0x8b3/0xc10 kernel/printk/printk.c:2829\n univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681\n console_init+0x49d/0x6d3 kernel/printk/printk.c:2915\n start_kernel+0x5e9/0x879 init/main.c:713\n secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241\n\n-\u003e #0 (console_owner){....}-{0:0}:\n [...]\n lock_acquire+0x127/0x340 kernel/locking/lockdep.c:4734\n console_trylock_spinning kernel/printk/printk.c:1773 \n---truncated---" }, { "lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: tty: se corrige el bloqueo causado por llamar a printk() bajo tty_port-\u0026gt;lock pty_write() invoca kmalloc() que puede invocar un printk() normal para imprimir un mensaje de error. Esto puede causar un bloqueo en el escenario informado por syz-bot a continuaci\u00f3n: CPU0 CPU1 CPU2 ---- ---- ---- lock(console_owner); lock(\u0026amp;port_lock_key); lock(\u0026amp;port-\u0026gt;lock); lock(\u0026amp;port_lock_key); lock(\u0026amp;port-\u0026gt;lock); lock(console_owner); Como dijo el commit dbdda842fe96 (\"printk: Agregar l\u00f3gica de propietario y espera de consola para equilibrar la carga de escrituras de consola\"), dicho bloqueo se puede prevenir usando printk_deferred() en kmalloc() (que se invoca en la secci\u00f3n protegida por port-\u0026gt;lock). Pero hay demasiados printk() en la ruta kmalloc() y kmalloc() se puede llamar desde cualquier lugar, por lo que cambiar printk() a printk_deferred() es demasiado complicado y poco elegante. Por lo tanto, este parche elige especificar __GFP_NOWARN en kmalloc(), de modo que no se llame a printk() y se pueda evitar este problema de bloqueo. Syzbot inform\u00f3 el siguiente error de lockdep: ======================================================== ADVERTENCIA: posible dependencia de bloqueo circular detectada 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+0x2ca/0x470 kernel/printk/printk.c:2023 but task is already holding lock: ffff8880119c9158 (\u0026amp;port-\u0026gt;lock){-.-.}-{2:2}, at: pty_write+0xf4/0x1f0 drivers/tty/pty.c:120 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -\u0026gt; #2 (\u0026amp;port-\u0026gt;lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 tty_port_tty_get drivers/tty/tty_port.c:288 [inline] \u0026lt;-- lock(\u0026amp;port-\u0026gt;lock); tty_port_default_wakeup+0x1d/0xb0 drivers/tty/tty_port.c:47 serial8250_tx_chars+0x530/0xa80 drivers/tty/serial/8250/8250_port.c:1767 serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1854 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1827 [inline] \u0026lt;-- lock(\u0026amp;port_lock_key); serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1870 serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x109/0xa50 kernel/irq/handle.c:156 [...] -\u0026gt; #1 (\u0026amp;port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x35/0x50 kernel/locking/spinlock.c:159 serial8250_console_write+0x184/0xa40 drivers/tty/serial/8250/8250_port.c:3198 \u0026lt;-- lock(\u0026amp;port_lock_key); call_console_drivers kernel/printk/printk.c:1819 [inline] console_unlock+0x8cb/0xd00 kernel/printk/printk.c:2504 vprintk_emit+0x1b5/0x470 kernel/printk/printk.c:2024 \u0026lt;-- lock(console_owner); vprintk_func+0x8d/0x250 kernel/printk/printk_safe.c:394 printk+0xba/0xed kernel/printk/printk.c:2084 register_console+0x8b3/0xc10 kernel/printk/printk.c:2829 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:681 console_init+0x49d/0x6d3 kernel/printk/printk.c:2915 start_kernel+0x5e9/0x879 init/main.c:713 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241 -\u0026gt; #0 (console_owner){....}-{0:0}: [...] lock_acquire+0x127/0x340 kernel/locking/lockdep.c:4734 console_trylock_spinning kernel/printk/printk.c:1773 ---truncated--- " } ], "id": "CVE-2022-49441", "lastModified": "2025-03-17T16:53:58.013", "metrics": { "cvssMetricV31": [ { "cvssData": { "attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary" } ] }, "published": "2025-02-26T07:01:20.523", "references": [ { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/04ee31678c128a6cc7bb057ea189a8624ba5a314" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/0bcf44903ef4df742dcada86ccaedd25374ffb50" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/18ca0d55e8639b911df8aae1b47598b13f9acded" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/3219ac364ac3d8d30771612a6010f1e0b7fa0a28" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/4af21b12a60ed2d3642284f4f85b42d7dc6ac246" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/4c253caf9264d2aa47ee806a87986dd8eb91a5d9" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/6b9dbedbe3499fef862c4dff5217cf91f34e43b3" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/9834b13e8b962caa28fbcf1f422dd82413da4ede" }, { "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": [ "Patch" ], "url": "https://git.kernel.org/stable/c/b3c974501d0c32258ae0e04e5cc3fb92383b40f6" } ], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [ { "description": [ { "lang": "en", "value": "CWE-667" } ], "source": "nvd@nist.gov", "type": "Primary" } ] }
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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.
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