CVE-2025-38523 — cifs: Fix the smbd_response slab to allow usercopy

Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

cifs: Fix the smbd_response slab to allow usercopy

The handling of received data in the smbdirect client code involves using copy_to_iter() to copy data from the smbd_reponse struct's packet trailer to a folioq buffer provided by netfslib that encapsulates a chunk of pagecache.

If, however, CONFIG_HARDENED_USERCOPY=y, this will result in the checks then performed in copy_to_iter() oopsing with something like the following:

CIFS: Attempting to mount //172.31.9.1/test CIFS: VFS: RDMA transport established usercopy: Kernel memory exposure attempt detected from SLUB object 'smbd_response_0000000091e24ea1' (offset 81, size 63)! ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:102! ... RIP: 0010:usercopy_abort+0x6c/0x80 ... Call Trace: <TASK> __check_heap_object+0xe3/0x120 __check_object_size+0x4dc/0x6d0 smbd_recv+0x77f/0xfe0 [cifs] cifs_readv_from_socket+0x276/0x8f0 [cifs] cifs_read_from_socket+0xcd/0x120 [cifs] cifs_demultiplex_thread+0x7e9/0x2d50 [cifs] kthread+0x396/0x830 ret_from_fork+0x2b8/0x3b0 ret_from_fork_asm+0x1a/0x30

The problem is that the smbd_response slab's packet field isn't marked as being permitted for usercopy.

Fix this by passing parameters to kmem_slab_create() to indicate that copy_to_iter() is permitted from the packet region of the smbd_response slab objects, less the header space.

USN-7833-1 — linux, linux-aws, linux-gcp, linux-oem-6.14, linux-oracle, linux-oracle-6.14, linux-raspi, linux-realtime vulnerabiliti…

Affected: Ubuntu:24.04:LTS: linux-oem-6.14, Ubuntu:24.04:LTS: linux-oracle-6.14

Oleksii Oleksenko, Cedric Fournet, Jana Hofmann, Boris Köpf, Stavros Volos, and Flavien Solt discovered that some AMD processors may allow an attacker to infer data from previous stores, potentially resulting in the leakage of privileged information. A local attacker could possibly use this to expose sensitive information. (CVE-2024-36350, CVE-2024-36357)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - ARM64 architecture; - PowerPC architecture; - RISC-V architecture; - S390 architecture; - x86 architecture; - ACPI drivers; - Serial ATA and Parallel ATA drivers; - Drivers core; - ATA over ethernet (AOE) driver; - Ublk userspace block driver; - Bus devices; - DMA engine subsystem; - Arm Firmware Framework for ARMv8-A(FFA); - Cirrus firmware drivers; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - I2C subsystem; - InfiniBand drivers; - Input Device (Miscellaneous) drivers; - Multiple devices driver; - Media drivers; - TI TPS6594 PFSM driver; - MMC subsystem; - MTD block device drivers; - Network drivers; - NVME drivers; - x86 platform drivers; - RapidIO drivers; - Voltage and Current Regulator drivers; - Remote Processor subsystem; - S/390 drivers; - SCSI subsystem; - TCM subsystem; - Trusted Execution Environment drivers; - TTY drivers; - ChipIdea USB dr…

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CVE-2025-38523 — cifs: Fix the smbd_response slab to allow usercopy

USN-7833-1 — linux, linux-aws, linux-gcp, linux-oem-6.14, linux-oracle, linux-oracle-6.14, linux-raspi, linux-realtime vulnerabiliti…