CVE-2025-40052
- ULN >
- Oracle Linux CVE repository >
- CVE-2025-40052
CVE Details
| Release Date: | 2025-10-28 | |
| Impact: | Moderate | What is this? |
Description
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix crypto buffers in non-linear memory
The crypto API, through the scatterlist API, expects input buffers to be
in linear memory. We handle this with the cifs_sg_set_buf() helper
that converts vmalloc'd memory to their corresponding pages.
However, when we allocate our aead_request buffer (@creq in
smb2ops.c::crypt_message()), we do so with kvzalloc(), which possibly
puts aead_request->__ctx in vmalloc area.
AEAD algorithm then uses ->__ctx for its private/internal data and
operations, and uses sg_set_buf() for such data on a few places.
This works fine as long as @creq falls into kmalloc zone (small
requests) or vmalloc'd memory is still within linear range.
Tasks' stacks are vmalloc'd by default (CONFIG_VMAP_STACK=y), so too
many tasks will increment the base stacks' addresses to a point where
virt_addr_valid(buf) will fail (BUG() in sg_set_buf()) when that
happens.
In practice: too many parallel reads and writes on an encrypted mount
will trigger this bug.
To fix this, always alloc @creq with kmalloc() instead.
Also drop the @sensitive_size variable/arguments since
kfree_sensitive() doesn't need it.
Backtrace:
[ 945.272081] ------------[ cut here ]------------
[ 945.272774] kernel BUG at include/linux/scatterlist.h:209!
[ 945.273520] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI
[ 945.274412] CPU: 7 UID: 0 PID: 56 Comm: kworker/u33:0 Kdump: loaded Not tainted 6.15.0-lku-11779-g8e9d6efccdd7-dirty #1 PREEMPT(voluntary)
[ 945.275736] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014
[ 945.276877] Workqueue: writeback wb_workfn (flush-cifs-2)
[ 945.277457] RIP: 0010:crypto_gcm_init_common+0x1f9/0x220
[ 945.278018] Code: b0 00 00 00 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 c7 c0 00 00 00 80 48 2b 05 5c 58 e5 00 e9 58 ff ff ff <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 48 c7 04 24 01 00 00 00 48 8b
[ 945.279992] RSP: 0018:ffffc90000a27360 EFLAGS: 00010246
[ 945.280578] RAX: 0000000000000000 RBX: ffffc90001d85060 RCX: 0000000000000030
[ 945.281376] RDX: 0000000000080000 RSI: 0000000000000000 RDI: ffffc90081d85070
[ 945.282145] RBP: ffffc90001d85010 R08: ffffc90001d85000 R09: 0000000000000000
[ 945.282898] R10: ffffc90001d85090 R11: 0000000000001000 R12: ffffc90001d85070
[ 945.283656] R13: ffff888113522948 R14: ffffc90001d85060 R15: ffffc90001d85010
[ 945.284407] FS: 0000000000000000(0000) GS:ffff8882e66cf000(0000) knlGS:0000000000000000
[ 945.285262] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 945.285884] CR2: 00007fa7ffdd31f4 CR3: 000000010540d000 CR4: 0000000000350ef0
[ 945.286683] Call Trace:
[ 945.286952]
See more information about CVE-2025-40052 from MITRE CVE dictionary and NIST NVD
NOTE: The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 metrics
| Base Score: | 6.2 |
| Vector String: | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Version: | 3.1 |
| Attack Vector: | Local |
| Attack Complexity: | Low |
| Privileges Required: | None |
| User Interaction: | None |
| Scope: | Unchanged |
| Confidentiality Impact: | None |
| Integrity Impact: | None |
| Availability Impact: | High |
Errata information
| Platform | Errata | Release Date |
| Oracle Linux version 10 (kernel-uek) | ELSA-2025-28040 | 2025-12-10 |
| Oracle Linux version 9 (kernel-uek) | ELSA-2025-28040 | 2025-12-10 |
This page is generated automatically and has not been checked for errors or omissions. For clarification or corrections:
- Oracle customers - enter a support request
- Vulnerability scanning tools vendors and project maintainers - follow the standard ISV process
