{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2022-49441", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2022-49441", "idYear": 2022, "status": "PUBLISHED", "publishedAt": "2025-02-26T02:12:54.649Z", "updatedAt": "2026-05-23T15:22:17.184Z", "importedAt": "2026-10-24T01:56:49.724Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "tty: fix deadlock caused by calling printk() under tty_port->lock", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: fix deadlock caused by calling printk() under tty_port->lock\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(&port_lock_key);\n lock(&port->lock);\n lock(&port_lock_key);\n lock(&port->lock);\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->lock). 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 (&port->lock){-.-.}-{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-> #2 (&port->lock){-.-.}-{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<-- lock(&port->lock);\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<-- lock(&port_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-> #1 (&port_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<-- lock(&port_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<-- 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-> #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---", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "d83904cb2eb2c4d937eaf15032214b0578f25099", "status": "affected", "versionType": "git", "lessThan": "4af21b12a60ed2d3642284f4f85b42d7dc6ac246" }, { "version": "deb1feaad03a78b545c949e54582ae57b3c56982", "status": "affected", "versionType": "git", "lessThan": "4c253caf9264d2aa47ee806a87986dd8eb91a5d9" }, { "version": "b6da31b2c07c46f2dcad1d86caa835227a16d9ff", "status": "affected", "versionType": "git", "lessThan": "04ee31678c128a6cc7bb057ea189a8624ba5a314" }, { "version": "b6da31b2c07c46f2dcad1d86caa835227a16d9ff", "status": "affected", "versionType": "git", "lessThan": "3219ac364ac3d8d30771612a6010f1e0b7fa0a28" }, { "version": "b6da31b2c07c46f2dcad1d86caa835227a16d9ff", "status": "affected", "versionType": "git", "lessThan": "9834b13e8b962caa28fbcf1f422dd82413da4ede" }, { "version": "b6da31b2c07c46f2dcad1d86caa835227a16d9ff", "status": "affected", "versionType": "git", "lessThan": "18ca0d55e8639b911df8aae1b47598b13f9acded" }, { "version": "b6da31b2c07c46f2dcad1d86caa835227a16d9ff", "status": "affected", "versionType": "git", "lessThan": "b3c974501d0c32258ae0e04e5cc3fb92383b40f6" }, { "version": "b6da31b2c07c46f2dcad1d86caa835227a16d9ff", "status": "affected", "versionType": "git", "lessThan": "0bcf44903ef4df742dcada86ccaedd25374ffb50" }, { "version": "b6da31b2c07c46f2dcad1d86caa835227a16d9ff", "status": "affected", "versionType": "git", "lessThan": "6b9dbedbe3499fef862c4dff5217cf91f34e43b3" }, { "version": "6d9cd12792270773fab9e5a129daff328d61ef9e", "status": "affected", "versionType": "git" }, { "version": "6dbfa9b5ae65063cd61dc7fa11332e00bb794d8b", "status": "affected", "versionType": "git" }, { "version": "60c4e8db32815474bfaeabe888ebb14e698caea1", "status": "affected", "versionType": "git" }, { "version": "4.9.117", "status": "affected", "versionType": "semver", "lessThan": "4.9.318" }, { "version": "4.14.60", "status": "affected", "versionType": "semver", "lessThan": "4.14.283" }, { "version": "3.18.118", "status": "affected", "versionType": "semver", "lessThan": "3.19" }, { "version": "4.4.146", "status": "affected", "versionType": "semver", "lessThan": "4.5" }, { "version": "4.17.12", "status": "affected", "versionType": "semver", "lessThan": "4.18" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.18", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.18" }, { "version": "4.9.318", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.9.*" }, { "version": "4.14.283", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.14.*" }, { "version": "4.19.247", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "4.19.*" }, { "version": "5.4.198", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.121", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.46", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "5.17.14", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.17.*" }, { "version": "5.18.3", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.18.*" }, { "version": "5.19", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }