kernel/git/stable/linux.git/fs/cifs/dfs.c, branch master

smb: move client and server files to common directory fs/smb

2023-05-24T21:29:21+00:00

Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko and helper modules) to new fs/smb subdirectory: fs/cifs --> fs/smb/client fs/ksmbd --> fs/smb/server fs/smbfs_common --> fs/smb/common Suggested-by: Linus Torvalds Acked-by: Namjae Jeon Signed-off-by: Steve French

cifs: fix smb1 mount regression

2023-05-24T21:22:44+00:00

cifs.ko maps NT_STATUS_NOT_FOUND to -EIO when SMB1 servers couldn't resolve referral paths. Proceed to tree connect when we get -EIO from dfs_get_referral() as well. Reported-by: Kris Karas (Bug Reporting) Tested-by: Woody Suwalski Fixes: 8e3554150d6c ("cifs: fix sharing of DFS connections") Cc: stable@vger.kernel.org # v6.2+ Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: fix sharing of DFS connections

2023-05-04T21:54:44+00:00

When matching DFS connections, we can't rely on the values set in cifs_sb_info::prepath and cifs_tcon::tree_name as they might change during DFS failover. The DFS referrals related to a specific DFS tcon are already matched earlier in match_server(), therefore we can safely skip those checks altogether as the connection is guaranteed to be unique for the DFS tcon. Besides, when creating or finding an SMB session, make sure to also refcount any DFS root session related to it (cifs_ses::dfs_root_ses), so if a new DFS mount ends up reusing the connection from the old mount while there was an umount(2) still in progress (e.g. umount(2) -> cifs_umount() -> reconnect -> cifs_put_tcon()), the connection could potentially be put right after the umount(2) finished. Patch has minor update to include fix for unused variable issue noted by the kernel test robot Reported-by: kernel test robot Link: https://lore.kernel.org/oe-kbuild-all/202305041040.j7W2xQSy-lkp@intel.com/ Cc: stable@vger.kernel.org # v6.2+ Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: avoid potential races when handling multiple dfs tcons

2023-05-04T04:29:47+00:00

Now that a DFS tcon manages its own list of DFS referrals and sessions, there is no point in having a single worker to refresh referrals of all DFS tcons. Make it faster and less prone to race conditions when having several mounts by queueing a worker per DFS tcon that will take care of refreshing only the DFS referrals related to it. Cc: stable@vger.kernel.org # v6.2+ Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: protect access of TCP_Server_Info::{origin,leaf}_fullpath

2023-05-04T04:29:39+00:00

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) Signed-off-by: Steve French

cifs: fix potential race when tree connecting ipc

2023-05-04T04:29:05+00:00

Protect access of TCP_Server_Info::hostname when building the ipc tree name as it might get freed in cifsd thread and thus causing an use-after-free bug in __tree_connect_dfs_target(). Also, while at it, update status of IPC tcon on success and then avoid any extra tree connects. Cc: stable@vger.kernel.org # v6.2+ Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: check only tcon status on tcon related functions

2023-03-17T18:22:22+00:00

We had a couple of checks for session in cifs_tree_connect and cifs_mark_open_files_invalid, which were unnecessary. And that was done with ses_lock. Changed that to tc_lock too. Signed-off-by: Shyam Prasad N Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: fix use-after-free bug in refresh_cache_worker()

2023-03-15T02:07:44+00:00

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] [ 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] Signed-off-by: Paulo Alcantara (SUSE) Cc: stable@vger.kernel.org # 6.2 Signed-off-by: Steve French

cifs: set DFS root session in cifs_get_smb_ses()

2023-03-15T02:05:53+00:00

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) Cc: stable@vger.kernel.org # 6.2 Signed-off-by: Steve French

cifs: protect access of TCP_Server_Info::{dstaddr,hostname}

2023-01-04T15:06:53+00:00

Use the appropriate locks to protect access of hostname and dstaddr fields in cifs_tree_connect() as they might get changed by other tasks. Signed-off-by: Paulo Alcantara (SUSE) Reviewed-by: Enzo Matsumiya Signed-off-by: Steve French