cbcvebase.
CVE-2025-38517
published 2025-08-16

CVE-2025-38517: In the Linux kernel, the following vulnerability has been resolved: lib/alloc_tag: do not acquire non-existent lock in alloc_tag_top_users()…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.14%
4.1th percentile
In the Linux kernel, the following vulnerability has been resolved: lib/alloc_tag: do not acquire non-existent lock in alloc_tag_top_users() alloc_tag_top_users() attempts to lock alloc_tag_cttype->mod_lock even when the alloc_tag_cttype is not allocated because: 1) alloc tagging is disabled because mem profiling is disabled (!alloc_tag_cttype) 2) alloc tagging is enabled, but not yet initialized (!alloc_tag_cttype) 3) alloc tagging is enabled, but failed initialization (!alloc_tag_cttype or IS_ERR(alloc_tag_cttype)) In all cases, alloc_tag_cttype is not allocated, and therefore alloc_tag_top_users() should not attempt to acquire the semaphore. This leads to a crash on memory allocation failure by attempting to acquire a non-existent semaphore: Oops: general protection fault, probably for non-canonical address 0xdffffc000000001b: 0000 [#3] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x00000000000000d8-0x00000000000000df] CPU: 2 UID: 0 PID: 1 Comm: systemd Tainted: G D 6.16.0-rc2 #1 VOLUNTARY Tainted: [D]=DIE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:down_read_trylock+0xaa/0x3b0 Code: d0 7c 08 84 d2 0f 85 a0 02 00 00 8b 0d df 31 dd 04 85 c9 75 29 48 b8 00 00 00 00 00 fc ff df 48 8d 6b 68 48 89 ea 48 c1 ea 03 3c 02 00 0f 85 88 02 00 00 48 3b 5b 68 0f 85 53 01 00 00 65 ff RSP: 0000:ffff8881002ce9b8 EFLAGS: 00010016 RAX: dffffc0000000000 RBX: 0000000000000070 RCX: 0000000000000000 RDX: 000000000000001b RSI: 000000000000000a RDI: 0000000000000070 RBP: 00000000000000d8 R08: 0000000000000001 R09: ffffed107dde49d1 R10: ffff8883eef24e8b R11: ffff8881002cec20 R12: 1ffff11020059d37 R13: 00000000003fff7b R14: ffff8881002cec20 R15: dffffc0000000000 FS: 00007f963f21d940(0000) GS:ffff888458ca6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f963f5edf71 CR3: 000000010672c000 CR4: 0000000000350ef0 Call Trace: codetag_trylock_module_list+0xd/0x20 alloc_tag_top_users+0x3

Affected

10 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.16.3-1 (forky)linux 6.16.3-1 (forky)
linuxlinux
linuxlinux>= 1438d349d16b78d88f9e978a4a5496f078c8191b < febc0b5dbabda414565bdfaaaa59d26f787d5fe7febc0b5dbabda414565bdfaaaa59d26f787d5fe7
linuxlinux>= 1438d349d16b78d88f9e978a4a5496f078c8191b < 22bf79c0c2301b6e15a688220284b147774d277e22bf79c0c2301b6e15a688220284b147774d277e
linuxlinux>= 1438d349d16b78d88f9e978a4a5496f078c8191b < 99af22cd34688cc0d535a1919e0bea4cbc6c1ea199af22cd34688cc0d535a1919e0bea4cbc6c1ea1
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.41-16.12.41-1
linuxlinux_kernel>= 0 < 6.16.3-16.16.3-1
linuxlinux_kernel>= 6.10 < 6.12.396.12.39
linuxlinux_kernel>= 6.13 < 6.15.76.15.7

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
vendor_ubuntu3.2LOW
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