{"id":"CVE-2025-39765","title":"ALSA: timer: fix ida_free call while not allocated","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: timer: fix ida_free call while not allocated\n\nIn the snd_utimer_create() function, if the kasprintf() function return\nNULL, snd_utimer_put_id() will be called, fi…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 37745918e0e7575bc40f38da93a99b9fa6406224 < 34327b362ce2849a5eb02f47e800049e7a20a0ba","Linux >= 37745918e0e7575bc40f38da93a99b9fa6406224 < af386b52531d14c4b20f11c452787b1b6dd4eb8d","Linux >= 37745918e0e7575bc40f38da93a99b9fa6406224 < 5003a65790ed66be882d1987cc2ca86af0de3db1","Linux 6.12"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T21:11:12.363470Z"},"published":"2025-09-11","updated":"2026-11-05","sourceUpdated":"2026-11-05T21:12:57.466Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-39765","references":[{"url":"https://git.kernel.org/stable/c/34327b362ce2849a5eb02f47e800049e7a20a0ba"},{"url":"https://git.kernel.org/stable/c/af386b52531d14c4b20f11c452787b1b6dd4eb8d"},{"url":"https://git.kernel.org/stable/c/5003a65790ed66be882d1987cc2ca86af0de3db1"}],"tags":["cve.org"],"epss":0.00157,"epssPercentile":0.04914,"ingestedAt":"2026-11-05T22:38:32.026Z","slug":"CVE-2025-39765","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nALSA: timer: fix ida_free call while not allocated\n\nIn the snd_utimer_create() function, if the kasprintf() function return\nNULL, snd_utimer_put_id() will be called, finally use ida_free()\nto free the unallocated id 0.\n\nthe syzkaller reported the following information:\n  ------------[ cut here ]------------\n  ida_free called for id=0 which is not allocated.\n  WARNING: CPU: 1 PID: 1286 at lib/idr.c:592 ida_free+0x1fd/0x2f0 lib/idr.c:592\n  Modules linked in:\n  CPU: 1 UID: 0 PID: 1286 Comm: syz-executor164 Not tainted 6.15.8 #3 PREEMPT(lazy)\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014\n  RIP: 0010:ida_free+0x1fd/0x2f0 lib/idr.c:592\n  Code: f8 fc 41 83 fc 3e 76 69 e8 70 b2 f8 (...)\n  RSP: 0018:ffffc900007f79c8 EFLAGS: 00010282\n  RAX: 0000000000000000 RBX: 1ffff920000fef3b RCX: ffffffff872176a5\n  RDX: ffff88800369d200 RSI: 0000000000000000 RDI: ffff88800369d200\n  RBP: 0000000000000000 R08: ffffffff87ba60a5 R09: 0000000000000000\n  R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000\n  R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000\n  FS:  00007f6f1abc1740(0000) GS:ffff8880d76a0000(0000) knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: 00007f6f1ad7a784 CR3: 000000007a6e2000 CR4: 00000000000006f0\n  Call Trace:\n   <TASK>\n   snd_utimer_put_id sound/core/timer.c:2043 [inline] [snd_timer]\n   snd_utimer_create+0x59b/0x6a0 sound/core/timer.c:2184 [snd_timer]\n   snd_utimer_ioctl_create sound/core/timer.c:2202 [inline] [snd_timer]\n   __snd_timer_user_ioctl.isra.0+0x724/0x1340 sound/core/timer.c:2287 [snd_timer]\n   snd_timer_user_ioctl+0x75/0xc0 sound/core/timer.c:2298 [snd_timer]\n   vfs_ioctl fs/ioctl.c:51 [inline]\n   __do_sys_ioctl fs/ioctl.c:907 [inline]\n   __se_sys_ioctl fs/ioctl.c:893 [inline]\n   __x64_sys_ioctl+0x198/0x200 fs/ioctl.c:893\n   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n   do_syscall_64+0x7b/0x160 arch/x86/entry/syscall_64.c:94\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e\n  [...]\n\nThe utimer->id should be set properly before the kasprintf() function,\nensures the snd_utimer_put_id() function will free the allocated id.\n\n## Affected\n\n- `Linux >= 37745918e0e7575bc40f38da93a99b9fa6406224 < 34327b362ce2849a5eb02f47e800049e7a20a0ba`\n- `Linux >= 37745918e0e7575bc40f38da93a99b9fa6406224 < af386b52531d14c4b20f11c452787b1b6dd4eb8d`\n- `Linux >= 37745918e0e7575bc40f38da93a99b9fa6406224 < 5003a65790ed66be882d1987cc2ca86af0de3db1`\n- `Linux 6.12`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}