linux-stable.git/fs/cifs, branch linux-5.4.y Linux kernel stable tree cifs: fix integer overflow in match_server() 2025-09-09T16:44:02+00:00 Roman Smirnov r.smirnov@omp.ru 2025-09-07T15:08:36+00:00 1be4500cfa60c0d40576188f82c53cef03181b8a [ Upstream commit 2510859475d7f46ed7940db0853f3342bf1b65ee ] The echo_interval is not limited in any way during mounting, which makes it possible to write a large number to it. This can cause an overflow when multiplying ctx->echo_interval by HZ in match_server(). Add constraints for echo_interval to smb3_fs_context_parse_param(). Found by Linux Verification Center (linuxtesting.org) with Svace. Fixes: adfeb3e00e8e1 ("cifs: Make echo interval tunable") Cc: stable@vger.kernel.org Signed-off-by: Roman Smirnov <r.smirnov@omp.ru> Signed-off-by: Steve French <stfrench@microsoft.com> [ Adapted to older CIFS filesystem structure and mount option parsing ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 2510859475d7f46ed7940db0853f3342bf1b65ee ]

The echo_interval is not limited in any way during mounting,
which makes it possible to write a large number to it. This can
cause an overflow when multiplying ctx->echo_interval by HZ in
match_server().

Add constraints for echo_interval to smb3_fs_context_parse_param().

Found by Linux Verification Center (linuxtesting.org) with Svace.

Fixes: adfeb3e00e8e1 ("cifs: Make echo interval tunable")
Cc: stable@vger.kernel.org
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
[ Adapted to older CIFS filesystem structure and mount option parsing ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: Fix UAF in cifs_demultiplex_thread() 2025-08-28T14:21:36+00:00 Zhang Xiaoxu zhangxiaoxu5@huawei.com 2023-09-19T18:38:04+00:00 fe87e2d0e6265859c659a3ef1e2559a83c5e8e68 commit d527f51331cace562393a8038d870b3e9916686f upstream. There is a UAF when xfstests on cifs: BUG: KASAN: use-after-free in smb2_is_network_name_deleted+0x27/0x160 Read of size 4 at addr ffff88810103fc08 by task cifsd/923 CPU: 1 PID: 923 Comm: cifsd Not tainted 6.1.0-rc4+ #45 ... Call Trace: <TASK> dump_stack_lvl+0x34/0x44 print_report+0x171/0x472 kasan_report+0xad/0x130 kasan_check_range+0x145/0x1a0 smb2_is_network_name_deleted+0x27/0x160 cifs_demultiplex_thread.cold+0x172/0x5a4 kthread+0x165/0x1a0 ret_from_fork+0x1f/0x30 </TASK> Allocated by task 923: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_slab_alloc+0x54/0x60 kmem_cache_alloc+0x147/0x320 mempool_alloc+0xe1/0x260 cifs_small_buf_get+0x24/0x60 allocate_buffers+0xa1/0x1c0 cifs_demultiplex_thread+0x199/0x10d0 kthread+0x165/0x1a0 ret_from_fork+0x1f/0x30 Freed by task 921: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x143/0x1b0 kmem_cache_free+0xe3/0x4d0 cifs_small_buf_release+0x29/0x90 SMB2_negotiate+0x8b7/0x1c60 smb2_negotiate+0x51/0x70 cifs_negotiate_protocol+0xf0/0x160 cifs_get_smb_ses+0x5fa/0x13c0 mount_get_conns+0x7a/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The UAF is because: mount(pid: 921) | cifsd(pid: 923) -------------------------------|------------------------------- | cifs_demultiplex_thread SMB2_negotiate | cifs_send_recv | compound_send_recv | smb_send_rqst | wait_for_response | wait_event_state [1] | | standard_receive3 | cifs_handle_standard | handle_mid | mid->resp_buf = buf; [2] | dequeue_mid [3] KILL the process [4] | resp_iov[i].iov_base = buf | free_rsp_buf [5] | | is_network_name_deleted [6] | callback 1. After send request to server, wait the response until mid->mid_state != SUBMITTED; 2. Receive response from server, and set it to mid; 3. Set the mid state to RECEIVED; 4. Kill the process, the mid state already RECEIVED, get 0; 5. Handle and release the negotiate response; 6. UAF. It can be easily reproduce with add some delay in [3] - [6]. Only sync call has the problem since async call's callback is executed in cifsd process. Add an extra state to mark the mid state to READY before wakeup the waitter, then it can get the resp safely. Fixes: ec637e3ffb6b ("[CIFS] Avoid extra large buffer allocation (and memcpy) in cifs_readpages") Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> [fs/cifs was moved to fs/smb/client since 38c8a9a52082 ("smb: move client and server files to common directory fs/smb"). We apply the patch to fs/cifs with some minor context changes.] Signed-off-by: He Zhe <zhe.he@windriver.com> Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com> [ chanho: Backported to v5.4.y ] Signed-off-by: Chanho Min <chanho.min@lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d527f51331cace562393a8038d870b3e9916686f upstream.

There is a UAF when xfstests on cifs:

  BUG: KASAN: use-after-free in smb2_is_network_name_deleted+0x27/0x160
  Read of size 4 at addr ffff88810103fc08 by task cifsd/923

  CPU: 1 PID: 923 Comm: cifsd Not tainted 6.1.0-rc4+ #45
  ...
  Call Trace:
   <TASK>
   dump_stack_lvl+0x34/0x44
   print_report+0x171/0x472
   kasan_report+0xad/0x130
   kasan_check_range+0x145/0x1a0
   smb2_is_network_name_deleted+0x27/0x160
   cifs_demultiplex_thread.cold+0x172/0x5a4
   kthread+0x165/0x1a0
   ret_from_fork+0x1f/0x30
   </TASK>

  Allocated by task 923:
   kasan_save_stack+0x1e/0x40
   kasan_set_track+0x21/0x30
   __kasan_slab_alloc+0x54/0x60
   kmem_cache_alloc+0x147/0x320
   mempool_alloc+0xe1/0x260
   cifs_small_buf_get+0x24/0x60
   allocate_buffers+0xa1/0x1c0
   cifs_demultiplex_thread+0x199/0x10d0
   kthread+0x165/0x1a0
   ret_from_fork+0x1f/0x30

  Freed by task 921:
   kasan_save_stack+0x1e/0x40
   kasan_set_track+0x21/0x30
   kasan_save_free_info+0x2a/0x40
   ____kasan_slab_free+0x143/0x1b0
   kmem_cache_free+0xe3/0x4d0
   cifs_small_buf_release+0x29/0x90
   SMB2_negotiate+0x8b7/0x1c60
   smb2_negotiate+0x51/0x70
   cifs_negotiate_protocol+0xf0/0x160
   cifs_get_smb_ses+0x5fa/0x13c0
   mount_get_conns+0x7a/0x750
   cifs_mount+0x103/0xd00
   cifs_smb3_do_mount+0x1dd/0xcb0
   smb3_get_tree+0x1d5/0x300
   vfs_get_tree+0x41/0xf0
   path_mount+0x9b3/0xdd0
   __x64_sys_mount+0x190/0x1d0
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0

The UAF is because:

 mount(pid: 921)               | cifsd(pid: 923)
-------------------------------|-------------------------------
                               | cifs_demultiplex_thread
SMB2_negotiate                 |
 cifs_send_recv                |
  compound_send_recv           |
   smb_send_rqst               |
    wait_for_response          |
     wait_event_state      [1] |
                               |  standard_receive3
                               |   cifs_handle_standard
                               |    handle_mid
                               |     mid->resp_buf = buf;  [2]
                               |     dequeue_mid           [3]
     KILL the process      [4] |
    resp_iov[i].iov_base = buf |
 free_rsp_buf              [5] |
                               |   is_network_name_deleted [6]
                               |   callback

1. After send request to server, wait the response until
    mid->mid_state != SUBMITTED;
2. Receive response from server, and set it to mid;
3. Set the mid state to RECEIVED;
4. Kill the process, the mid state already RECEIVED, get 0;
5. Handle and release the negotiate response;
6. UAF.

It can be easily reproduce with add some delay in [3] - [6].

Only sync call has the problem since async call's callback is
executed in cifsd process.

Add an extra state to mark the mid state to READY before wakeup the
waitter, then it can get the resp safely.

Fixes: ec637e3ffb6b ("[CIFS] Avoid extra large buffer allocation (and memcpy) in cifs_readpages")
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
[fs/cifs was moved to fs/smb/client since
38c8a9a52082 ("smb: move client and server files to common directory fs/smb").
We apply the patch to fs/cifs with some minor context changes.]
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
[ chanho: Backported to v5.4.y ]
Signed-off-by: Chanho Min <chanho.min@lge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: Fix calling CIFSFindFirst() for root path without msearch 2025-08-28T14:21:27+00:00 Pali Rohár pali@kernel.org 2024-12-30T19:54:11+00:00 9f69a595a2a13dd76e685507e8160ee46ba56d83 [ Upstream commit b460249b9a1dab7a9f58483e5349d045ad6d585c ] To query root path (without msearch wildcard) it is needed to send pattern '\' instead of '' (empty string). This allows to use CIFSFindFirst() to query information about root path which is being used in followup changes. This change fixes the stat() syscall called on the root path on the mount. It is because stat() syscall uses the cifs_query_path_info() function and it can fallback to the CIFSFindFirst() usage with msearch=false. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b460249b9a1dab7a9f58483e5349d045ad6d585c ]

To query root path (without msearch wildcard) it is needed to
send pattern '\' instead of '' (empty string).

This allows to use CIFSFindFirst() to query information about root path
which is being used in followup changes.

This change fixes the stat() syscall called on the root path on the mount.
It is because stat() syscall uses the cifs_query_path_info() function and
it can fallback to the CIFSFindFirst() usage with msearch=false.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
smb: client: let recv_done() cleanup before notifying the callers. 2025-08-28T14:21:22+00:00 Stefan Metzmacher metze@samba.org 2025-08-04T12:10:15+00:00 0fbf5e367d7684fd5138cb3099cc7f7c8d16f93b [ Upstream commit bdd7afc6dca5e0ebbb75583484aa6ea9e03fbb13 ] We should call put_receive_buffer() before waking up the callers. For the internal error case of response->type being unexpected, we now also call smbd_disconnect_rdma_connection() instead of not waking up the callers at all. Note that the SMBD_TRANSFER_DATA case still has problems, which will be addressed in the next commit in order to make it easier to review this one. Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Long Li <longli@microsoft.com> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Fixes: f198186aa9bb ("CIFS: SMBD: Establish SMB Direct connection") Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit bdd7afc6dca5e0ebbb75583484aa6ea9e03fbb13 ]

We should call put_receive_buffer() before waking up the callers.

For the internal error case of response->type being unexpected,
we now also call smbd_disconnect_rdma_connection() instead
of not waking up the callers at all.

Note that the SMBD_TRANSFER_DATA case still has problems,
which will be addressed in the next commit in order to make
it easier to review this one.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: f198186aa9bb ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cifs: Fix cifs_query_path_info() for Windows NT servers 2025-07-17T16:24:49+00:00 Pali Rohár pali@kernel.org 2024-12-31T15:06:22+00:00 816104692002770f8b4ab9d47e3f2c40c26cefc5 [ Upstream commit a3e771afbb3bce91c8296828304903e7348003fe ] For TRANS2 QUERY_PATH_INFO request when the path does not exist, the Windows NT SMB server returns error response STATUS_OBJECT_NAME_NOT_FOUND or ERRDOS/ERRbadfile without the SMBFLG_RESPONSE flag set. Similarly it returns STATUS_DELETE_PENDING when the file is being deleted. And looks like that any error response from TRANS2 QUERY_PATH_INFO does not have SMBFLG_RESPONSE flag set. So relax check in check_smb_hdr() for detecting if the packet is response for this special case. This change fixes stat() operation against Windows NT SMB servers and also all operations which depends on -ENOENT result from stat like creat() or mkdir(). Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a3e771afbb3bce91c8296828304903e7348003fe ]

For TRANS2 QUERY_PATH_INFO request when the path does not exist, the
Windows NT SMB server returns error response STATUS_OBJECT_NAME_NOT_FOUND
or ERRDOS/ERRbadfile without the SMBFLG_RESPONSE flag set. Similarly it
returns STATUS_DELETE_PENDING when the file is being deleted. And looks
like that any error response from TRANS2 QUERY_PATH_INFO does not have
SMBFLG_RESPONSE flag set.

So relax check in check_smb_hdr() for detecting if the packet is response
for this special case.

This change fixes stat() operation against Windows NT SMB servers and also
all operations which depends on -ENOENT result from stat like creat() or
mkdir().

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
smb: client: Reset all search buffer pointers when releasing buffer 2025-06-04T12:32:36+00:00 Wang Zhaolong wangzhaolong1@huawei.com 2025-05-16T09:12:56+00:00 9f5748b6948174ec51d2a8a35598b224e74566d7 commit e48f9d849bfdec276eebf782a84fd4dfbe1c14c0 upstream. Multiple pointers in struct cifs_search_info (ntwrk_buf_start, srch_entries_start, and last_entry) point to the same allocated buffer. However, when freeing this buffer, only ntwrk_buf_start was set to NULL, while the other pointers remained pointing to freed memory. This is defensive programming to prevent potential issues with stale pointers. While the active UAF vulnerability is fixed by the previous patch, this change ensures consistent pointer state and more robust error handling. Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com> Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e48f9d849bfdec276eebf782a84fd4dfbe1c14c0 upstream.

Multiple pointers in struct cifs_search_info (ntwrk_buf_start,
srch_entries_start, and last_entry) point to the same allocated buffer.
However, when freeing this buffer, only ntwrk_buf_start was set to NULL,
while the other pointers remained pointing to freed memory.

This is defensive programming to prevent potential issues with stale
pointers. While the active UAF vulnerability is fixed by the previous
patch, this change ensures consistent pointer state and more robust error
handling.

Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
smb: client: Fix use-after-free in cifs_fill_dirent 2025-06-04T12:32:36+00:00 Wang Zhaolong wangzhaolong1@huawei.com 2025-05-16T09:12:55+00:00 aee067e88d61eb72e966f094e4749c6b14e7008f commit a7a8fe56e932a36f43e031b398aef92341bf5ea0 upstream. There is a race condition in the readdir concurrency process, which may access the rsp buffer after it has been released, triggering the following KASAN warning. ================================================================== BUG: KASAN: slab-use-after-free in cifs_fill_dirent+0xb03/0xb60 [cifs] Read of size 4 at addr ffff8880099b819c by task a.out/342975 CPU: 2 UID: 0 PID: 342975 Comm: a.out Not tainted 6.15.0-rc6+ #240 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x53/0x70 print_report+0xce/0x640 kasan_report+0xb8/0xf0 cifs_fill_dirent+0xb03/0xb60 [cifs] cifs_readdir+0x12cb/0x3190 [cifs] iterate_dir+0x1a1/0x520 __x64_sys_getdents+0x134/0x220 do_syscall_64+0x4b/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f996f64b9f9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0d f7 c3 0c 00 f7 d8 64 89 8 RSP: 002b:00007f996f53de78 EFLAGS: 00000207 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007f996f53ecdc RCX: 00007f996f64b9f9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f996f53dea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000207 R12: ffffffffffffff88 R13: 0000000000000000 R14: 00007ffc8cd9a500 R15: 00007f996f51e000 </TASK> Allocated by task 408: kasan_save_stack+0x20/0x40 kasan_save_track+0x14/0x30 __kasan_slab_alloc+0x6e/0x70 kmem_cache_alloc_noprof+0x117/0x3d0 mempool_alloc_noprof+0xf2/0x2c0 cifs_buf_get+0x36/0x80 [cifs] allocate_buffers+0x1d2/0x330 [cifs] cifs_demultiplex_thread+0x22b/0x2690 [cifs] kthread+0x394/0x720 ret_from_fork+0x34/0x70 ret_from_fork_asm+0x1a/0x30 Freed by task 342979: kasan_save_stack+0x20/0x40 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x37/0x50 kmem_cache_free+0x2b8/0x500 cifs_buf_release+0x3c/0x70 [cifs] cifs_readdir+0x1c97/0x3190 [cifs] iterate_dir+0x1a1/0x520 __x64_sys_getdents64+0x134/0x220 do_syscall_64+0x4b/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e The buggy address belongs to the object at ffff8880099b8000 which belongs to the cache cifs_request of size 16588 The buggy address is located 412 bytes inside of freed 16588-byte region [ffff8880099b8000, ffff8880099bc0cc) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x99b8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff888001e03400 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000010001 00000000f5000000 0000000000000000 head: 0080000000000040 ffff888001e03400 0000000000000000 dead000000000001 head: 0000000000000000 0000000000010001 00000000f5000000 0000000000000000 head: 0080000000000003 ffffea0000266e01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880099b8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880099b8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880099b8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880099b8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880099b8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== POC is available in the link [1]. The problem triggering process is as follows: Process 1 Process 2 ----------------------------------------------------------------- cifs_readdir /* file->private_data == NULL */ initiate_cifs_search cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL); smb2_query_dir_first ->query_dir_first() SMB2_query_directory SMB2_query_directory_init cifs_send_recv smb2_parse_query_directory srch_inf->ntwrk_buf_start = (char *)rsp; srch_inf->srch_entries_start = (char *)rsp + ... srch_inf->last_entry = (char *)rsp + ... srch_inf->smallBuf = true; find_cifs_entry /* if (cfile->srch_inf.ntwrk_buf_start) */ cifs_small_buf_release(cfile->srch_inf // free cifs_readdir ->iterate_shared() /* file->private_data != NULL */ find_cifs_entry /* in while (...) loop */ smb2_query_dir_next ->query_dir_next() SMB2_query_directory SMB2_query_directory_init cifs_send_recv compound_send_recv smb_send_rqst __smb_send_rqst rc = -ERESTARTSYS; /* if (fatal_signal_pending()) */ goto out; return rc /* if (cfile->srch_inf.last_entry) */ cifs_save_resume_key() cifs_fill_dirent // UAF /* if (rc) */ return -ENOENT; Fix this by ensuring the return code is checked before using pointers from the srch_inf. Link: https://bugzilla.kernel.org/show_bug.cgi?id=220131 [1] Fixes: a364bc0b37f1 ("[CIFS] fix saving of resume key before CIFSFindNext") Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a7a8fe56e932a36f43e031b398aef92341bf5ea0 upstream.

There is a race condition in the readdir concurrency process, which may
access the rsp buffer after it has been released, triggering the
following KASAN warning.

 ==================================================================
 BUG: KASAN: slab-use-after-free in cifs_fill_dirent+0xb03/0xb60 [cifs]
 Read of size 4 at addr ffff8880099b819c by task a.out/342975

 CPU: 2 UID: 0 PID: 342975 Comm: a.out Not tainted 6.15.0-rc6+ #240 PREEMPT(full)
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x53/0x70
  print_report+0xce/0x640
  kasan_report+0xb8/0xf0
  cifs_fill_dirent+0xb03/0xb60 [cifs]
  cifs_readdir+0x12cb/0x3190 [cifs]
  iterate_dir+0x1a1/0x520
  __x64_sys_getdents+0x134/0x220
  do_syscall_64+0x4b/0x110
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
 RIP: 0033:0x7f996f64b9f9
 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89
 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01
 f0 ff ff  0d f7 c3 0c 00 f7 d8 64 89 8
 RSP: 002b:00007f996f53de78 EFLAGS: 00000207 ORIG_RAX: 000000000000004e
 RAX: ffffffffffffffda RBX: 00007f996f53ecdc RCX: 00007f996f64b9f9
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
 RBP: 00007f996f53dea0 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000207 R12: ffffffffffffff88
 R13: 0000000000000000 R14: 00007ffc8cd9a500 R15: 00007f996f51e000
  </TASK>

 Allocated by task 408:
  kasan_save_stack+0x20/0x40
  kasan_save_track+0x14/0x30
  __kasan_slab_alloc+0x6e/0x70
  kmem_cache_alloc_noprof+0x117/0x3d0
  mempool_alloc_noprof+0xf2/0x2c0
  cifs_buf_get+0x36/0x80 [cifs]
  allocate_buffers+0x1d2/0x330 [cifs]
  cifs_demultiplex_thread+0x22b/0x2690 [cifs]
  kthread+0x394/0x720
  ret_from_fork+0x34/0x70
  ret_from_fork_asm+0x1a/0x30

 Freed by task 342979:
  kasan_save_stack+0x20/0x40
  kasan_save_track+0x14/0x30
  kasan_save_free_info+0x3b/0x60
  __kasan_slab_free+0x37/0x50
  kmem_cache_free+0x2b8/0x500
  cifs_buf_release+0x3c/0x70 [cifs]
  cifs_readdir+0x1c97/0x3190 [cifs]
  iterate_dir+0x1a1/0x520
  __x64_sys_getdents64+0x134/0x220
  do_syscall_64+0x4b/0x110
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

 The buggy address belongs to the object at ffff8880099b8000
  which belongs to the cache cifs_request of size 16588
 The buggy address is located 412 bytes inside of
  freed 16588-byte region [ffff8880099b8000, ffff8880099bc0cc)

 The buggy address belongs to the physical page:
 page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x99b8
 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
 anon flags: 0x80000000000040(head|node=0|zone=1)
 page_type: f5(slab)
 raw: 0080000000000040 ffff888001e03400 0000000000000000 dead000000000001
 raw: 0000000000000000 0000000000010001 00000000f5000000 0000000000000000
 head: 0080000000000040 ffff888001e03400 0000000000000000 dead000000000001
 head: 0000000000000000 0000000000010001 00000000f5000000 0000000000000000
 head: 0080000000000003 ffffea0000266e01 00000000ffffffff 00000000ffffffff
 head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff8880099b8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8880099b8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 >ffff8880099b8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                             ^
  ffff8880099b8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8880099b8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ==================================================================

POC is available in the link [1].

The problem triggering process is as follows:

Process 1                       Process 2
-----------------------------------------------------------------
cifs_readdir
  /* file->private_data == NULL */
  initiate_cifs_search
    cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
    smb2_query_dir_first ->query_dir_first()
      SMB2_query_directory
        SMB2_query_directory_init
        cifs_send_recv
        smb2_parse_query_directory
          srch_inf->ntwrk_buf_start = (char *)rsp;
          srch_inf->srch_entries_start = (char *)rsp + ...
          srch_inf->last_entry = (char *)rsp + ...
          srch_inf->smallBuf = true;
  find_cifs_entry
    /* if (cfile->srch_inf.ntwrk_buf_start) */
    cifs_small_buf_release(cfile->srch_inf // free

                        cifs_readdir  ->iterate_shared()
                          /* file->private_data != NULL */
                          find_cifs_entry
                            /* in while (...) loop */
                            smb2_query_dir_next  ->query_dir_next()
                              SMB2_query_directory
                                SMB2_query_directory_init
                                cifs_send_recv
                                  compound_send_recv
                                    smb_send_rqst
                                    __smb_send_rqst
                                      rc = -ERESTARTSYS;
                                      /* if (fatal_signal_pending()) */
                                      goto out;
                                      return rc
                            /* if (cfile->srch_inf.last_entry) */
                            cifs_save_resume_key()
                              cifs_fill_dirent // UAF
                            /* if (rc) */
                            return -ENOENT;

Fix this by ensuring the return code is checked before using pointers
from the srch_inf.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=220131 [1]
Fixes: a364bc0b37f1 ("[CIFS] fix saving of resume key before CIFSFindNext")
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cifs: Fix buffer overflow when parsing NFS reparse points 2024-12-14T18:44:21+00:00 Pali Rohár pali@kernel.org 2024-11-22T15:29:43+00:00 7b222d6cb87077faf56a687a72af1951cf78c8a9 commit e2a8910af01653c1c268984855629d71fb81f404 upstream. ReparseDataLength is sum of the InodeType size and DataBuffer size. So to get DataBuffer size it is needed to subtract InodeType's size from ReparseDataLength. Function cifs_strndup_from_utf16() is currentlly accessing buf->DataBuffer at position after the end of the buffer because it does not subtract InodeType size from the length. Fix this problem and correctly subtract variable len. Member InodeType is present only when reparse buffer is large enough. Check for ReparseDataLength before accessing InodeType to prevent another invalid memory access. Major and minor rdev values are present also only when reparse buffer is large enough. Check for reparse buffer size before calling reparse_mkdev(). Fixes: d5ecebc4900d ("smb3: Allow query of symlinks stored as reparse points") Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> [use variable name symlink_buf, the other buf->InodeType accesses are not used in current version so skip] Signed-off-by: Mahmoud Adam <mngyadam@amazon.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit e2a8910af01653c1c268984855629d71fb81f404 upstream.

ReparseDataLength is sum of the InodeType size and DataBuffer size.
So to get DataBuffer size it is needed to subtract InodeType's size from
ReparseDataLength.

Function cifs_strndup_from_utf16() is currentlly accessing buf->DataBuffer
at position after the end of the buffer because it does not subtract
InodeType size from the length. Fix this problem and correctly subtract
variable len.

Member InodeType is present only when reparse buffer is large enough. Check
for ReparseDataLength before accessing InodeType to prevent another invalid
memory access.

Major and minor rdev values are present also only when reparse buffer is
large enough. Check for reparse buffer size before calling reparse_mkdev().

Fixes: d5ecebc4900d ("smb3: Allow query of symlinks stored as reparse points")
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
[use variable name symlink_buf, the other buf->InodeType accesses are
not used in current version so skip]
Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
smb: client: fix OOBs when building SMB2_IOCTL request 2024-11-08T15:20:50+00:00 Paulo Alcantara pc@manguebit.com 2024-10-15T22:04:04+00:00 6f0516ef1290da24b85461ed08a0938af7415e49 [ Upstream commit 1ab60323c5201bef25f2a3dc0ccc404d9aca77f1 ] When using encryption, either enforced by the server or when using 'seal' mount option, the client will squash all compound request buffers down for encryption into a single iov in smb2_set_next_command(). SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the SMB2_IOCTL request in the first iov, and if the user passes an input buffer that is greater than 328 bytes, smb2_set_next_command() will end up writing off the end of @rqst->iov[0].iov_base as shown below: mount.cifs //srv/share /mnt -o ...,seal ln -s $(perl -e "print('a')for 1..1024") /mnt/link BUG: KASAN: slab-out-of-bounds in smb2_set_next_command.cold+0x1d6/0x24c [cifs] Write of size 4116 at addr ffff8881148fcab8 by task ln/859 CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 ? smb2_set_next_command.cold+0x1d6/0x24c [cifs] print_report+0x156/0x4d9 ? smb2_set_next_command.cold+0x1d6/0x24c [cifs] ? __virt_addr_valid+0x145/0x310 ? __phys_addr+0x46/0x90 ? smb2_set_next_command.cold+0x1d6/0x24c [cifs] kasan_report+0xda/0x110 ? smb2_set_next_command.cold+0x1d6/0x24c [cifs] kasan_check_range+0x10f/0x1f0 __asan_memcpy+0x3c/0x60 smb2_set_next_command.cold+0x1d6/0x24c [cifs] smb2_compound_op+0x238c/0x3840 [cifs] ? kasan_save_track+0x14/0x30 ? kasan_save_free_info+0x3b/0x70 ? vfs_symlink+0x1a1/0x2c0 ? do_symlinkat+0x108/0x1c0 ? __pfx_smb2_compound_op+0x10/0x10 [cifs] ? kmem_cache_free+0x118/0x3e0 ? cifs_get_writable_path+0xeb/0x1a0 [cifs] smb2_get_reparse_inode+0x423/0x540 [cifs] ? __pfx_smb2_get_reparse_inode+0x10/0x10 [cifs] ? rcu_is_watching+0x20/0x50 ? __kmalloc_noprof+0x37c/0x480 ? smb2_create_reparse_symlink+0x257/0x490 [cifs] ? smb2_create_reparse_symlink+0x38f/0x490 [cifs] smb2_create_reparse_symlink+0x38f/0x490 [cifs] ? __pfx_smb2_create_reparse_symlink+0x10/0x10 [cifs] ? find_held_lock+0x8a/0xa0 ? hlock_class+0x32/0xb0 ? __build_path_from_dentry_optional_prefix+0x19d/0x2e0 [cifs] cifs_symlink+0x24f/0x960 [cifs] ? __pfx_make_vfsuid+0x10/0x10 ? __pfx_cifs_symlink+0x10/0x10 [cifs] ? make_vfsgid+0x6b/0xc0 ? generic_permission+0x96/0x2d0 vfs_symlink+0x1a1/0x2c0 do_symlinkat+0x108/0x1c0 ? __pfx_do_symlinkat+0x10/0x10 ? strncpy_from_user+0xaa/0x160 __x64_sys_symlinkat+0xb9/0xf0 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08d75c13bb Reported-by: David Howells <dhowells@redhat.com> Fixes: e77fe73c7e38 ("cifs: we can not use small padding iovs together with encryption") Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1ab60323c5201bef25f2a3dc0ccc404d9aca77f1 ]

When using encryption, either enforced by the server or when using
'seal' mount option, the client will squash all compound request buffers
down for encryption into a single iov in smb2_set_next_command().

SMB2_ioctl_init() allocates a small buffer (448 bytes) to hold the
SMB2_IOCTL request in the first iov, and if the user passes an input
buffer that is greater than 328 bytes, smb2_set_next_command() will
end up writing off the end of @rqst->iov[0].iov_base as shown below:

  mount.cifs //srv/share /mnt -o ...,seal
  ln -s $(perl -e "print('a')for 1..1024") /mnt/link

  BUG: KASAN: slab-out-of-bounds in
  smb2_set_next_command.cold+0x1d6/0x24c [cifs]
  Write of size 4116 at addr ffff8881148fcab8 by task ln/859

  CPU: 1 UID: 0 PID: 859 Comm: ln Not tainted 6.12.0-rc3 #1
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
  1.16.3-2.fc40 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x5d/0x80
   ? smb2_set_next_command.cold+0x1d6/0x24c [cifs]
   print_report+0x156/0x4d9
   ? smb2_set_next_command.cold+0x1d6/0x24c [cifs]
   ? __virt_addr_valid+0x145/0x310
   ? __phys_addr+0x46/0x90
   ? smb2_set_next_command.cold+0x1d6/0x24c [cifs]
   kasan_report+0xda/0x110
   ? smb2_set_next_command.cold+0x1d6/0x24c [cifs]
   kasan_check_range+0x10f/0x1f0
   __asan_memcpy+0x3c/0x60
   smb2_set_next_command.cold+0x1d6/0x24c [cifs]
   smb2_compound_op+0x238c/0x3840 [cifs]
   ? kasan_save_track+0x14/0x30
   ? kasan_save_free_info+0x3b/0x70
   ? vfs_symlink+0x1a1/0x2c0
   ? do_symlinkat+0x108/0x1c0
   ? __pfx_smb2_compound_op+0x10/0x10 [cifs]
   ? kmem_cache_free+0x118/0x3e0
   ? cifs_get_writable_path+0xeb/0x1a0 [cifs]
   smb2_get_reparse_inode+0x423/0x540 [cifs]
   ? __pfx_smb2_get_reparse_inode+0x10/0x10 [cifs]
   ? rcu_is_watching+0x20/0x50
   ? __kmalloc_noprof+0x37c/0x480
   ? smb2_create_reparse_symlink+0x257/0x490 [cifs]
   ? smb2_create_reparse_symlink+0x38f/0x490 [cifs]
   smb2_create_reparse_symlink+0x38f/0x490 [cifs]
   ? __pfx_smb2_create_reparse_symlink+0x10/0x10 [cifs]
   ? find_held_lock+0x8a/0xa0
   ? hlock_class+0x32/0xb0
   ? __build_path_from_dentry_optional_prefix+0x19d/0x2e0 [cifs]
   cifs_symlink+0x24f/0x960 [cifs]
   ? __pfx_make_vfsuid+0x10/0x10
   ? __pfx_cifs_symlink+0x10/0x10 [cifs]
   ? make_vfsgid+0x6b/0xc0
   ? generic_permission+0x96/0x2d0
   vfs_symlink+0x1a1/0x2c0
   do_symlinkat+0x108/0x1c0
   ? __pfx_do_symlinkat+0x10/0x10
   ? strncpy_from_user+0xaa/0x160
   __x64_sys_symlinkat+0xb9/0xf0
   do_syscall_64+0xbb/0x1d0
   entry_SYSCALL_64_after_hwframe+0x77/0x7f
  RIP: 0033:0x7f08d75c13bb

Reported-by: David Howells <dhowells@redhat.com>
Fixes: e77fe73c7e38 ("cifs: we can not use small padding iovs together with encryption")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
smb: client: fix potential OOBs in smb2_parse_contexts() 2024-05-25T14:17:17+00:00 Paulo Alcantara pc@manguebit.com 2023-12-11T13:26:41+00:00 6726429c18c62dbf5e96ebbd522f262e016553fb commit af1689a9b7701d9907dfc84d2a4b57c4bc907144 upstream. Validate offsets and lengths before dereferencing create contexts in smb2_parse_contexts(). This fixes following oops when accessing invalid create contexts from server: BUG: unable to handle page fault for address: ffff8881178d8cc3 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 4a01067 P4D 4a01067 PUD 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 1736 Comm: mount.cifs Not tainted 6.7.0-rc4 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 RIP: 0010:smb2_parse_contexts+0xa0/0x3a0 [cifs] Code: f8 10 75 13 48 b8 93 ad 25 50 9c b4 11 e7 49 39 06 0f 84 d2 00 00 00 8b 45 00 85 c0 74 61 41 29 c5 48 01 c5 41 83 fd 0f 76 55 <0f> b7 7d 04 0f b7 45 06 4c 8d 74 3d 00 66 83 f8 04 75 bc ba 04 00 RSP: 0018:ffffc900007939e0 EFLAGS: 00010216 RAX: ffffc90000793c78 RBX: ffff8880180cc000 RCX: ffffc90000793c90 RDX: ffffc90000793cc0 RSI: ffff8880178d8cc0 RDI: ffff8880180cc000 RBP: ffff8881178d8cbf R08: ffffc90000793c22 R09: 0000000000000000 R10: ffff8880180cc000 R11: 0000000000000024 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000000 R15: ffffc90000793c22 FS: 00007f873753cbc0(0000) GS:ffff88806bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8881178d8cc3 CR3: 00000000181ca000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? __die+0x23/0x70 ? page_fault_oops+0x181/0x480 ? search_module_extables+0x19/0x60 ? srso_alias_return_thunk+0x5/0xfbef5 ? exc_page_fault+0x1b6/0x1c0 ? asm_exc_page_fault+0x26/0x30 ? smb2_parse_contexts+0xa0/0x3a0 [cifs] SMB2_open+0x38d/0x5f0 [cifs] ? smb2_is_path_accessible+0x138/0x260 [cifs] smb2_is_path_accessible+0x138/0x260 [cifs] cifs_is_path_remote+0x8d/0x230 [cifs] cifs_mount+0x7e/0x350 [cifs] cifs_smb3_do_mount+0x128/0x780 [cifs] smb3_get_tree+0xd9/0x290 [cifs] vfs_get_tree+0x2c/0x100 ? capable+0x37/0x70 path_mount+0x2d7/0xb80 ? srso_alias_return_thunk+0x5/0xfbef5 ? _raw_spin_unlock_irqrestore+0x44/0x60 __x64_sys_mount+0x11a/0x150 do_syscall_64+0x47/0xf0 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f8737657b1e Reported-by: Robert Morris <rtm@csail.mit.edu> Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com> [Guru: Removed changes to cached_dir.c and checking return value of smb2_parse_contexts in smb2ops.c] Signed-off-by: Guruswamy Basavaiah <guruswamy.basavaiah@broadcom.com> [v5.4: Fixed merge-conflicts in smb2_parse_contexts for missing parameter POSIX response] Signed-off-by: Shaoying Xu <shaoyi@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit af1689a9b7701d9907dfc84d2a4b57c4bc907144 upstream.

Validate offsets and lengths before dereferencing create contexts in
smb2_parse_contexts().

This fixes following oops when accessing invalid create contexts from
server:

  BUG: unable to handle page fault for address: ffff8881178d8cc3
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 4a01067 P4D 4a01067 PUD 0
  Oops: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 3 PID: 1736 Comm: mount.cifs Not tainted 6.7.0-rc4 #1
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
  rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
  RIP: 0010:smb2_parse_contexts+0xa0/0x3a0 [cifs]
  Code: f8 10 75 13 48 b8 93 ad 25 50 9c b4 11 e7 49 39 06 0f 84 d2 00
  00 00 8b 45 00 85 c0 74 61 41 29 c5 48 01 c5 41 83 fd 0f 76 55 <0f> b7
  7d 04 0f b7 45 06 4c 8d 74 3d 00 66 83 f8 04 75 bc ba 04 00
  RSP: 0018:ffffc900007939e0 EFLAGS: 00010216
  RAX: ffffc90000793c78 RBX: ffff8880180cc000 RCX: ffffc90000793c90
  RDX: ffffc90000793cc0 RSI: ffff8880178d8cc0 RDI: ffff8880180cc000
  RBP: ffff8881178d8cbf R08: ffffc90000793c22 R09: 0000000000000000
  R10: ffff8880180cc000 R11: 0000000000000024 R12: 0000000000000000
  R13: 0000000000000020 R14: 0000000000000000 R15: ffffc90000793c22
  FS: 00007f873753cbc0(0000) GS:ffff88806bc00000(0000)
  knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffff8881178d8cc3 CR3: 00000000181ca000 CR4: 0000000000750ef0
  PKRU: 55555554
  Call Trace:
   <TASK>
   ? __die+0x23/0x70
   ? page_fault_oops+0x181/0x480
   ? search_module_extables+0x19/0x60
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? exc_page_fault+0x1b6/0x1c0
   ? asm_exc_page_fault+0x26/0x30
   ? smb2_parse_contexts+0xa0/0x3a0 [cifs]
   SMB2_open+0x38d/0x5f0 [cifs]
   ? smb2_is_path_accessible+0x138/0x260 [cifs]
   smb2_is_path_accessible+0x138/0x260 [cifs]
   cifs_is_path_remote+0x8d/0x230 [cifs]
   cifs_mount+0x7e/0x350 [cifs]
   cifs_smb3_do_mount+0x128/0x780 [cifs]
   smb3_get_tree+0xd9/0x290 [cifs]
   vfs_get_tree+0x2c/0x100
   ? capable+0x37/0x70
   path_mount+0x2d7/0xb80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? _raw_spin_unlock_irqrestore+0x44/0x60
   __x64_sys_mount+0x11a/0x150
   do_syscall_64+0x47/0xf0
   entry_SYSCALL_64_after_hwframe+0x6f/0x77
  RIP: 0033:0x7f8737657b1e

Reported-by: Robert Morris <rtm@csail.mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
[Guru: Removed changes to cached_dir.c and checking return value
of smb2_parse_contexts in smb2ops.c]
Signed-off-by: Guruswamy Basavaiah <guruswamy.basavaiah@broadcom.com>
[v5.4: Fixed merge-conflicts in smb2_parse_contexts for
missing parameter POSIX response]
Signed-off-by: Shaoying Xu <shaoyi@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>