Gh0st
/
linux
mirror of https://github.com/torvalds/linux.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

smb3: fix for slab out of bounds on mount to ksmbd 

With KASAN enabled, it is possible to get a slab out of bounds
during mount to ksmbd due to missing check in parse_server_interfaces()
(see below):

 BUG: KASAN: slab-out-of-bounds in
 parse_server_interfaces+0x14ee/0x1880 [cifs]
 Read of size 4 at addr ffff8881433dba98 by task mount/9827

 CPU: 5 UID: 0 PID: 9827 Comm: mount Tainted: G
 OE       6.16.0-rc2-kasan #2 PREEMPT(voluntary)
 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
 Hardware name: Dell Inc. Precision Tower 3620/0MWYPT,
 BIOS 2.13.1 06/14/2019
 Call Trace:
  <TASK>
 dump_stack_lvl+0x9f/0xf0
 print_report+0xd1/0x670
 __virt_addr_valid+0x22c/0x430
 ? parse_server_interfaces+0x14ee/0x1880 [cifs]
 ? kasan_complete_mode_report_info+0x2a/0x1f0
 ? parse_server_interfaces+0x14ee/0x1880 [cifs]
   kasan_report+0xd6/0x110
   parse_server_interfaces+0x14ee/0x1880 [cifs]
   __asan_report_load_n_noabort+0x13/0x20
   parse_server_interfaces+0x14ee/0x1880 [cifs]
 ? __pfx_parse_server_interfaces+0x10/0x10 [cifs]
 ? trace_hardirqs_on+0x51/0x60
 SMB3_request_interfaces+0x1ad/0x3f0 [cifs]
 ? __pfx_SMB3_request_interfaces+0x10/0x10 [cifs]
 ? SMB2_tcon+0x23c/0x15d0 [cifs]
 smb3_qfs_tcon+0x173/0x2b0 [cifs]
 ? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs]
 ? cifs_get_tcon+0x105d/0x2120 [cifs]
 ? do_raw_spin_unlock+0x5d/0x200
 ? cifs_get_tcon+0x105d/0x2120 [cifs]
 ? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs]
 cifs_mount_get_tcon+0x369/0xb90 [cifs]
 ? dfs_cache_find+0xe7/0x150 [cifs]
 dfs_mount_share+0x985/0x2970 [cifs]
 ? check_path.constprop.0+0x28/0x50
 ? save_trace+0x54/0x370
 ? __pfx_dfs_mount_share+0x10/0x10 [cifs]
 ? __lock_acquire+0xb82/0x2ba0
 ? __kasan_check_write+0x18/0x20
 cifs_mount+0xbc/0x9e0 [cifs]
 ? __pfx_cifs_mount+0x10/0x10 [cifs]
 ? do_raw_spin_unlock+0x5d/0x200
 ? cifs_setup_cifs_sb+0x29d/0x810 [cifs]
 cifs_smb3_do_mount+0x263/0x1990 [cifs]

Reported-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Steve French 2025-08-11 23:14:55 -05:00
parent d7f1affc55
commit 7d34ec36ab
1 changed files with 10 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
fs/smb/client/smb2ops.c
View File

@ -772,6 +772,13 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
bytes_left -= sizeof(*p);
break;
}
/* Validate that Next doesn't point beyond the buffer */
if (next > bytes_left) {
cifs_dbg(VFS, "%s: invalid Next pointer %zu > %zd\n",
__func__, next, bytes_left);
rc = -EINVAL;
goto out;
}
p = (struct network_interface_info_ioctl_rsp *)((u8 *)p+next);
bytes_left -= next;
}
@ -783,7 +790,9 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
}
/* Azure rounds the buffer size up 8, to a 16 byte boundary */
if ((bytes_left > 8) || p->Next)
if ((bytes_left > 8) ||
(bytes_left >= offsetof(struct network_interface_info_ioctl_rsp, Next)
+ sizeof(p->Next) && p->Next))
cifs_dbg(VFS, "%s: incomplete interface info\n", __func__);
ses->iface_last_update = jiffies;