{"cve":"CVE-2026-74504","nvd":{"published":"2026-08-15T13:17:55.427","modified":"2026-08-17T06:19:46.953","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: Fix division by zero in initialize_timer()\n\nA userspace-driven ALSA timer (SND_UTIMER) lets an unprivileged user set\nthe backing snd_timer's hardware resolution to an arbitrary 64-bit value\nvia SNDRV_TIMER_IOCTL_CREATE. snd_utimer_create() only rejects zero.\n\nWhen such a timer is bound to a sequencer queue, initialize_timer()\ncomputes the tick period as\n\n\ttmr->ticks = 1000000000 / (r * freq);\n\nwhere r is that user-controlled resolution and freq is the sequencer\nupdate rate in Hz, clamped to MIN_FREQUENCY..MAX_FREQUENCY (10..6250).\nA resolution of 2^63 makes the 64-bit product r * freq wrap to zero for\nany even freq, including DEFAULT_FREQUENCY (1000), so the division faults\nwith a divide-by-zero.\n\nThe division runs under tmr->lock with interrupts disabled, so the oops\nleaves the spinlock held and hangs the CPU. It is reachable by an\nunprivileged user with access to /dev/snd/timer and /dev/snd/seq.\n\n  Oops: divide error: 0000 [#1] SMP KASAN PTI\n  CPU: 7 UID: 1000 PID: 456 Comm: alsa_seq_utimer Not tainted 7.2.0-rc4+\n  RIP: 0010:initialize_timer.constprop.0+0x20a/0x2d0\n   snd_seq_timer_start+0x15e/0x2b0\n   snd_seq_control_queue+0x56f/0xba0\n   snd_seq_write+0x3e0/0x730\n\nReject an overflowing product with check_mul_overflow() and fall back to\na single tick, which also avoids feeding a wrapped-but-nonzero divisor\n(e.g. 2^63 * 1000 mod 2^64 == 0, or other resolutions wrapping to a small\nvalue) into the period computation.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/21e19688433452dfbbbe6b2bb670dea6eb92f0f6","https://git.kernel.org/stable/c/42c6543ff27ea280334244458d4f52ec7133cc05","https://git.kernel.org/stable/c/5260e195c53e898a4a76527d4bb2178f31795e78","https://git.kernel.org/stable/c/d0e19932875746118e298b4c974f3b2d4aeb16fc"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:10.689564601+00:00"},"epss":{"cve":"CVE-2026-74504","score":0.00168,"percentile":0.06076,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}