smb: client: fix max_sge overflow in smb_extract_folioq_to_rdma()
CVE: CVE-2025-38179
Component: kernel
CWE: CWE-190
Severity: Moderate
CVSS v3: 7.5/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
Release date: 2025-07-04T00:00:00+00:00

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

smb: client: fix max_sge overflow in smb_extract_folioq_to_rdma()

This fixes the following problem:

[  749.901015] [   T8673] run fstests cifs/001 at 2025-06-17 09:40:30
[  750.346409] [   T9870] ==================================================================
[  750.346814] [   T9870] BUG: KASAN: slab-out-of-bounds in smb_set_sge+0x2cc/0x3b0 [cifs]
[  750.347330] [   T9870] Write of size 8 at addr ffff888011082890 by task xfs_io/9870
[  750.347705] [   T9870]
[  750.348077] [   T9870] CPU: 0 UID: 0 PID: 9870 Comm: xfs_io Kdump: loaded Not tainted 6.16.0-rc2-metze.02+ #1 PREEMPT(voluntary)
[  750.348082] [   T9870] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  750.348085] [   T9870] Call Trace:
[  750.348086] [   T9870]  <TASK>
[  750.348088] [   T9870]  dump_stack_lvl+0x76/0xa0
[  750.348106] [   T9870]  print_report+0xd1/0x640
[  750.348116] [   T9870]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  750.348120] [   T9870]  ? kasan_complete_mode_report_info+0x26/0x210
[  750.348124] [   T9870]  kasan_report+0xe7/0x130
[  750.348128] [   T9870]  ? smb_set_sge+0x2cc/0x3b0 [cifs]
[  750.348262] [   T9870]  ? smb_set_sge+0x2cc/0x3b0 [cifs]
[  750.348377] [   T9870]  __asan_report_store8_noabort+0x17/0x30
[  750.348381] [   T9870]  smb_set_sge+0x2cc/0x3b0 [cifs]
[  750.348496] [   T9870]  smbd_post_send_iter+0x1990/0x3070 [cifs]
[  750.348625] [   T9870]  ? __pfx_smbd_post_send_iter+0x10/0x10 [cifs]
[  750.348741] [   T9870]  ? update_stack_state+0x2a0/0x670
[  750.348749] [   T9870]  ? cifs_flush+0x153/0x320 [cifs]
[  750.348870] [   T9870]  ? cifs_flush+0x153/0x320 [cifs]
[  750.348990] [   T9870]  ? update_stack_state+0x2a0/0x670
[  750.348995] [   T9870]  smbd_send+0x58c/0x9c0 [cifs]
[  750.349117] [   T9870]  ? __pfx_smbd_send+0x10/0x10 [cifs]
[  750.349231] [   T9870]  ? unwind_get_return_address+0x65/0xb0
[  750.349235] [   T9870]  ? __pfx_stack_trace_consume_entry+0x10/0x10
[  750.349242] [   T9870]  ? arch_stack_walk+0xa7/0x100
[  750.349250] [   T9870]  ? stack_trace_save+0x92/0xd0
[  750.349254] [   T9870]  __smb_send_rqst+0x931/0xec0 [cifs]
[  750.349374] [   T9870]  ? kernel_text_address+0x173/0x190
[  750.349379] [   T9870]  ? kasan_save_stack+0x39/0x70
[  750.349382] [   T9870]  ? kasan_save_track+0x18/0x70
[  750.349385] [   T9870]  ? __kasan_slab_alloc+0x9d/0xa0
[  750.349389] [   T9870]  ? __pfx___smb_send_rqst+0x10/0x10 [cifs]
[  750.349508] [   T9870]  ? smb2_mid_entry_alloc+0xb4/0x7e0 [cifs]
[  750.349626] [   T9870]  ? cifs_call_async+0x277/0xb00 [cifs]
[  750.349746] [   T9870]  ? cifs_issue_write+0x256/0x610 [cifs]
[  750.349867] [   T9870]  ? netfs_do_issue_write+0xc2/0x340 [netfs]
[  750.349900] [   T9870]  ? netfs_advance_write+0x45b/0x1270 [netfs]
[  750.349929] [   T9870]  ? netfs_write_folio+0xd6c/0x1be0 [netfs]
[  750.349958] [   T9870]  ? netfs_writepages+0x2e9/0xa80 [netfs]
[  750.349987] [   T9870]  ? do_writepages+0x21f/0x590
[  750.349993] [   T9870]  ? filemap_fdatawrite_wbc+0xe1/0x140
[  750.349997] [   T9870]  ? entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  750.350002] [   T9870]  smb_send_rqst+0x22e/0x2f0 [cifs]
[  750.350131] [   T9870]  ? __pfx_smb_send_rqst+0x10/0x10 [cifs]
[  750.350255] [   T9870]  ? local_clock_noinstr+0xe/0xd0
[  750.350261] [   T9870]  ? kasan_save_alloc_info+0x37/0x60
[  750.350268] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.350271] [   T9870]  ? _raw_spin_lock+0x81/0xf0
[  750.350275] [   T9870]  ? __pfx__raw_spin_lock+0x10/0x10
[  750.350278] [   T9870]  ? smb2_setup_async_request+0x293/0x580 [cifs]
[  750.350398] [   T9870]  cifs_call_async+0x477/0xb00 [cifs]
[  750.350518] [   T9870]  ? __pfx_smb2_writev_callback+0x10/0x10 [cifs]
[  750.350636] [   T9870]  ? __pfx_cifs_call_async+0x10/0x10 [cifs]
[  750.350756] [   T9870]  ? __pfx__raw_spin_lock+0x10/0x10
[  750.350760] [   T9870]  ? __kasan_check_write+0x14/0x30
[  750.350763] [   T98
---truncated---


Remediation: