Vulnerability Details CVE-2025-39765
In the Linux kernel, the following vulnerability has been resolved:
ALSA: timer: fix ida_free call while not allocated
In the snd_utimer_create() function, if the kasprintf() function return
NULL, snd_utimer_put_id() will be called, finally use ida_free()
to free the unallocated id 0.
the syzkaller reported the following information:
------------[ cut here ]------------
ida_free called for id=0 which is not allocated.
WARNING: CPU: 1 PID: 1286 at lib/idr.c:592 ida_free+0x1fd/0x2f0 lib/idr.c:592
Modules linked in:
CPU: 1 UID: 0 PID: 1286 Comm: syz-executor164 Not tainted 6.15.8 #3 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-4.fc42 04/01/2014
RIP: 0010:ida_free+0x1fd/0x2f0 lib/idr.c:592
Code: f8 fc 41 83 fc 3e 76 69 e8 70 b2 f8 (...)
RSP: 0018:ffffc900007f79c8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 1ffff920000fef3b RCX: ffffffff872176a5
RDX: ffff88800369d200 RSI: 0000000000000000 RDI: ffff88800369d200
RBP: 0000000000000000 R08: ffffffff87ba60a5 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f6f1abc1740(0000) GS:ffff8880d76a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6f1ad7a784 CR3: 000000007a6e2000 CR4: 00000000000006f0
Call Trace:
<TASK>
snd_utimer_put_id sound/core/timer.c:2043 [inline] [snd_timer]
snd_utimer_create+0x59b/0x6a0 sound/core/timer.c:2184 [snd_timer]
snd_utimer_ioctl_create sound/core/timer.c:2202 [inline] [snd_timer]
__snd_timer_user_ioctl.isra.0+0x724/0x1340 sound/core/timer.c:2287 [snd_timer]
snd_timer_user_ioctl+0x75/0xc0 sound/core/timer.c:2298 [snd_timer]
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__x64_sys_ioctl+0x198/0x200 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x7b/0x160 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
[...]
The utimer->id should be set properly before the kasprintf() function,
ensures the snd_utimer_put_id() function will free the allocated id.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 5.7%
CVSS Severity
CVSS v3 Score 5.5
Products affected by CVE-2025-39765
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cpe:2.3:o:linux:linux_kernel:6.12
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cpe:2.3:o:linux:linux_kernel:6.12.1
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cpe:2.3:o:linux:linux_kernel:6.12.10
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cpe:2.3:o:linux:linux_kernel:6.12.11
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cpe:2.3:o:linux:linux_kernel:6.12.12
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cpe:2.3:o:linux:linux_kernel:6.12.13
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cpe:2.3:o:linux:linux_kernel:6.12.14
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cpe:2.3:o:linux:linux_kernel:6.12.15
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cpe:2.3:o:linux:linux_kernel:6.12.16
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cpe:2.3:o:linux:linux_kernel:6.12.17
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cpe:2.3:o:linux:linux_kernel:6.12.18
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cpe:2.3:o:linux:linux_kernel:6.12.19
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cpe:2.3:o:linux:linux_kernel:6.12.2
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cpe:2.3:o:linux:linux_kernel:6.12.20
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cpe:2.3:o:linux:linux_kernel:6.12.21
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cpe:2.3:o:linux:linux_kernel:6.12.22
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cpe:2.3:o:linux:linux_kernel:6.12.23
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cpe:2.3:o:linux:linux_kernel:6.12.24
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cpe:2.3:o:linux:linux_kernel:6.12.25
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cpe:2.3:o:linux:linux_kernel:6.12.26
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cpe:2.3:o:linux:linux_kernel:6.12.27
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cpe:2.3:o:linux:linux_kernel:6.12.28
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cpe:2.3:o:linux:linux_kernel:6.12.29
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cpe:2.3:o:linux:linux_kernel:6.12.3
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cpe:2.3:o:linux:linux_kernel:6.12.30
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cpe:2.3:o:linux:linux_kernel:6.12.31
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cpe:2.3:o:linux:linux_kernel:6.12.32
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cpe:2.3:o:linux:linux_kernel:6.12.33
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cpe:2.3:o:linux:linux_kernel:6.12.34
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cpe:2.3:o:linux:linux_kernel:6.12.35
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cpe:2.3:o:linux:linux_kernel:6.12.36
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cpe:2.3:o:linux:linux_kernel:6.12.37
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cpe:2.3:o:linux:linux_kernel:6.12.38
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cpe:2.3:o:linux:linux_kernel:6.12.39
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cpe:2.3:o:linux:linux_kernel:6.12.4
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cpe:2.3:o:linux:linux_kernel:6.12.40
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cpe:2.3:o:linux:linux_kernel:6.12.41
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cpe:2.3:o:linux:linux_kernel:6.12.42
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cpe:2.3:o:linux:linux_kernel:6.12.43
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cpe:2.3:o:linux:linux_kernel:6.12.5
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cpe:2.3:o:linux:linux_kernel:6.12.6
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cpe:2.3:o:linux:linux_kernel:6.12.7
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cpe:2.3:o:linux:linux_kernel:6.12.8
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cpe:2.3:o:linux:linux_kernel:6.12.9
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cpe:2.3:o:linux:linux_kernel:6.13
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cpe:2.3:o:linux:linux_kernel:6.13.1
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cpe:2.3:o:linux:linux_kernel:6.13.10
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cpe:2.3:o:linux:linux_kernel:6.13.11
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cpe:2.3:o:linux:linux_kernel:6.13.12
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cpe:2.3:o:linux:linux_kernel:6.13.2
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cpe:2.3:o:linux:linux_kernel:6.13.3
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cpe:2.3:o:linux:linux_kernel:6.13.4
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cpe:2.3:o:linux:linux_kernel:6.13.5
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cpe:2.3:o:linux:linux_kernel:6.13.6
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cpe:2.3:o:linux:linux_kernel:6.13.7
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cpe:2.3:o:linux:linux_kernel:6.13.8
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cpe:2.3:o:linux:linux_kernel:6.13.9
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cpe:2.3:o:linux:linux_kernel:6.14
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cpe:2.3:o:linux:linux_kernel:6.14.1
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cpe:2.3:o:linux:linux_kernel:6.14.10
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cpe:2.3:o:linux:linux_kernel:6.14.11
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cpe:2.3:o:linux:linux_kernel:6.14.2
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cpe:2.3:o:linux:linux_kernel:6.14.3
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cpe:2.3:o:linux:linux_kernel:6.14.4
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cpe:2.3:o:linux:linux_kernel:6.14.5
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cpe:2.3:o:linux:linux_kernel:6.14.6
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cpe:2.3:o:linux:linux_kernel:6.14.7
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cpe:2.3:o:linux:linux_kernel:6.14.8
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cpe:2.3:o:linux:linux_kernel:6.14.9
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cpe:2.3:o:linux:linux_kernel:6.15
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cpe:2.3:o:linux:linux_kernel:6.15.1
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cpe:2.3:o:linux:linux_kernel:6.15.10
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cpe:2.3:o:linux:linux_kernel:6.15.11
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cpe:2.3:o:linux:linux_kernel:6.15.2
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cpe:2.3:o:linux:linux_kernel:6.15.3
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cpe:2.3:o:linux:linux_kernel:6.15.4
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cpe:2.3:o:linux:linux_kernel:6.15.5
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cpe:2.3:o:linux:linux_kernel:6.15.6
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cpe:2.3:o:linux:linux_kernel:6.15.7
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cpe:2.3:o:linux:linux_kernel:6.15.8
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cpe:2.3:o:linux:linux_kernel:6.15.9
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cpe:2.3:o:linux:linux_kernel:6.16
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cpe:2.3:o:linux:linux_kernel:6.16.1
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cpe:2.3:o:linux:linux_kernel:6.16.2
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cpe:2.3:o:linux:linux_kernel:6.16.3
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cpe:2.3:o:linux:linux_kernel:6.17