Граф коммитов

7 Коммитов

Автор SHA1 Сообщение Дата
Paulo Alcantara 3dc9c433c9 cifs: protect access of TCP_Server_Info::{origin,leaf}_fullpath
Protect access of TCP_Server_Info::{origin,leaf}_fullpath when
matching DFS connections, and get rid of
TCP_Server_Info::current_fullpath while we're at it.

Cc: stable@vger.kernel.org # v6.2+
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-05-03 23:29:39 -05:00
Paulo Alcantara d5a863a153 cifs: avoid dup prefix path in dfs_get_automount_devname()
@server->origin_fullpath already contains the tree name + optional
prefix, so avoid calling __build_path_from_dentry_optional_prefix() as
it might end up duplicating prefix path from @cifs_sb->prepath into
final full path.

Instead, generate DFS full path by simply merging
@server->origin_fullpath with dentry's path.

This fixes the following case

	mount.cifs //root/dfs/dir /mnt/ -o ...
	ls /mnt/link

where cifs_dfs_do_automount() will call smb3_parse_devname() with
@devname set to "//root/dfs/dir/link" instead of
"//root/dfs/dir/dir/link".

Fixes: 7ad54b98fc ("cifs: use origin fullpath for automounts")
Cc: <stable@vger.kernel.org> # 6.2+
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-04-16 18:04:36 -05:00
Paulo Alcantara 396935de14 cifs: fix use-after-free bug in refresh_cache_worker()
The UAF bug occurred because we were putting DFS root sessions in
cifs_umount() while DFS cache refresher was being executed.

Make DFS root sessions have same lifetime as DFS tcons so we can avoid
the use-after-free bug is DFS cache refresher and other places that
require IPCs to get new DFS referrals on.  Also, get rid of mount
group handling in DFS cache as we no longer need it.

This fixes below use-after-free bug catched by KASAN

[ 379.946955] BUG: KASAN: use-after-free in __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.947642] Read of size 8 at addr ffff888018f57030 by task kworker/u4:3/56
[ 379.948096]
[ 379.948208] CPU: 0 PID: 56 Comm: kworker/u4:3 Not tainted 6.2.0-rc7-lku #23
[ 379.948661] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.16.0-0-gd239552-rebuilt.opensuse.org 04/01/2014
[ 379.949368] Workqueue: cifs-dfscache refresh_cache_worker [cifs]
[ 379.949942] Call Trace:
[ 379.950113] <TASK>
[ 379.950260] dump_stack_lvl+0x50/0x67
[ 379.950510] print_report+0x16a/0x48e
[ 379.950759] ? __virt_addr_valid+0xd8/0x160
[ 379.951040] ? __phys_addr+0x41/0x80
[ 379.951285] kasan_report+0xdb/0x110
[ 379.951533] ? __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.952056] ? __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.952585] __refresh_tcon.isra.0+0x10b/0xc10 [cifs]
[ 379.953096] ? __pfx___refresh_tcon.isra.0+0x10/0x10 [cifs]
[ 379.953637] ? __pfx___mutex_lock+0x10/0x10
[ 379.953915] ? lock_release+0xb6/0x720
[ 379.954167] ? __pfx_lock_acquire+0x10/0x10
[ 379.954443] ? refresh_cache_worker+0x34e/0x6d0 [cifs]
[ 379.954960] ? __pfx_wb_workfn+0x10/0x10
[ 379.955239] refresh_cache_worker+0x4ad/0x6d0 [cifs]
[ 379.955755] ? __pfx_refresh_cache_worker+0x10/0x10 [cifs]
[ 379.956323] ? __pfx_lock_acquired+0x10/0x10
[ 379.956615] ? read_word_at_a_time+0xe/0x20
[ 379.956898] ? lockdep_hardirqs_on_prepare+0x12/0x220
[ 379.957235] process_one_work+0x535/0x990
[ 379.957509] ? __pfx_process_one_work+0x10/0x10
[ 379.957812] ? lock_acquired+0xb7/0x5f0
[ 379.958069] ? __list_add_valid+0x37/0xd0
[ 379.958341] ? __list_add_valid+0x37/0xd0
[ 379.958611] worker_thread+0x8e/0x630
[ 379.958861] ? __pfx_worker_thread+0x10/0x10
[ 379.959148] kthread+0x17d/0x1b0
[ 379.959369] ? __pfx_kthread+0x10/0x10
[ 379.959630] ret_from_fork+0x2c/0x50
[ 379.959879] </TASK>

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Cc: stable@vger.kernel.org # 6.2
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-03-14 21:07:44 -05:00
Paulo Alcantara b56bce502f cifs: set DFS root session in cifs_get_smb_ses()
Set the DFS root session pointer earlier when creating a new SMB
session to prevent racing with smb2_reconnect(), cifs_reconnect_tcon()
and DFS cache refresher.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Cc: stable@vger.kernel.org # 6.2
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-03-14 21:05:53 -05:00
Paulo Alcantara 7ad54b98fc cifs: use origin fullpath for automounts
Use TCP_Server_Info::origin_fullpath instead of cifs_tcon::tree_name
when building source paths for automounts as it will be useful for
domain-based DFS referrals where the connections and referrals would
get either re-used from the cache or re-created when chasing the dfs
link.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19 08:03:12 -06:00
Paulo Alcantara a1c0d00572 cifs: share dfs connections and supers
When matching DFS superblocks we can't rely on either the server's
address or tcon's UNC name from mount(2) as the existing servers and
tcons might be connected to somewhere else.  Instead, check if
superblock is dfs, and if so, match its original source pathname with
the new mount's source pathname.

For DFS connections, instead of checking server's address, match its
referral path as it could be connected to different targets.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19 08:03:12 -06:00
Paulo Alcantara abdb1742a3 cifs: get rid of mount options string parsing
After switching to filesystem context support, we no longer need to
handle mount options string when chasing dfs referrals.  Now, we set
the new values directly into smb3_fs_context.

Start working on a separate source file to handle most dfs related
mount functions as connect.c has already became too big.  The
remaining functions will be moved gradually in follow-up patches.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-12-19 08:03:11 -06:00