Commit 3fe1bf42 authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Wang Zhaolong
Browse files

smb: client: fix use-after-free bug in cifs_debug_data_proc_show() 

mainline inclusion
from mainline-v6.7-rc1
commit d328c09ee9f15ee5a26431f5aad7c9239fa85e62
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4LM
CVE: CVE-2023-52752

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d328c09ee9f15ee5a26431f5aad7c9239fa85e62



--------------------------------

Skip SMB sessions that are being teared down
(e.g. @ses->ses_status == SES_EXITING) in cifs_debug_data_proc_show()
to avoid use-after-free in @ses.

This fixes the following GPF when reading from /proc/fs/cifs/DebugData
while mounting and umounting

  [ 816.251274] general protection fault, probably for non-canonical
  address 0x6b6b6b6b6b6b6d81: 0000 [#1] PREEMPT SMP NOPTI
  ...
  [  816.260138] Call Trace:
  [  816.260329]  <TASK>
  [  816.260499]  ? die_addr+0x36/0x90
  [  816.260762]  ? exc_general_protection+0x1b3/0x410
  [  816.261126]  ? asm_exc_general_protection+0x26/0x30
  [  816.261502]  ? cifs_debug_tcon+0xbd/0x240 [cifs]
  [  816.261878]  ? cifs_debug_tcon+0xab/0x240 [cifs]
  [  816.262249]  cifs_debug_data_proc_show+0x516/0xdb0 [cifs]
  [  816.262689]  ? seq_read_iter+0x379/0x470
  [  816.262995]  seq_read_iter+0x118/0x470
  [  816.263291]  proc_reg_read_iter+0x53/0x90
  [  816.263596]  ? srso_alias_return_thunk+0x5/0x7f
  [  816.263945]  vfs_read+0x201/0x350
  [  816.264211]  ksys_read+0x75/0x100
  [  816.264472]  do_syscall_64+0x3f/0x90
  [  816.264750]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
  [  816.265135] RIP: 0033:0x7fd5e669d381

Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
Conflicts:
    fs/smb/client/cifs_debug.c
    fs/cifs/cifs_debug.c
    fs/cifs/connect.c
[Path is changed and related functions has been refactored for a long time]
Signed-off-by: default avatarWang Zhaolong <wangzhaolong1@huawei.com>
parent 83e8197d

fs/cifs/cifs_debug.c

+2 −0
Original line number Diff line number Diff line
@@ -356,6 +356,8 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v) 
		list_for_each(tmp2, &server->smb_ses_list) {

			ses = list_entry(tmp2, struct cifs_ses,

					 smb_ses_list);

			if (ses->status == CifsExiting)

				continue;

			if ((ses->serverDomain == NULL) ||

				(ses->serverOS == NULL) ||

				(ses->serverNOS == NULL)) {

fs/cifs/connect.c

+1 −1
Original line number Diff line number Diff line
@@ -2877,12 +2877,12 @@ void cifs_put_smb_ses(struct cifs_ses *ses) 
		spin_unlock(&cifs_tcp_ses_lock);

		return;

	}

	spin_unlock(&cifs_tcp_ses_lock);



	spin_lock(&GlobalMid_Lock);

	if (ses->status == CifsGood)

		ses->status = CifsExiting;

	spin_unlock(&GlobalMid_Lock);

	spin_unlock(&cifs_tcp_ses_lock);



	cifs_free_ipc(ses);