diff options
| author |   Steve French <stfrench@microsoft.com> | 2025-08-11 23:14:55 -0500 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2025-08-13 11:36:02 -0500 |
| commit | 7d34ec36abb84fdfb6632a0f2cbda90379ae21fc (patch) | |
| tree | 2e50f68e41494c7fd20298a7aa21bf6a5ea3ef9a | |
| parent | cifs: avoid extra calls to strlen() in cifs_get_spnego_key() (diff) | |
| download | wireguard-linux-7d34ec36abb84fdfb6632a0f2cbda90379ae21fc.tar.xz wireguard-linux-7d34ec36abb84fdfb6632a0f2cbda90379ae21fc.zip | |
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>
| -rw-r--r-- | fs/smb/client/smb2ops.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index ad8947434b71..218b6ce7ff3a 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -772,6 +772,13 @@ next_iface: 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 @@ next_iface: } /* 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; |