Paulo Alcantara f62ffdfb43 smb: client: fix memory leak in cifs_construct_tcon()
commit 3184b6a5a24ec9ee74087b2a550476f386df7dc2 upstream.

When having a multiuser mount with domain= specified and using
cifscreds, cifs_set_cifscreds() will end up setting @ctx->domainname,
so it needs to be freed before leaving cifs_construct_tcon().

This fixes the following memory leak reported by kmemleak:

  mount.cifs //srv/share /mnt -o domain=ZELDA,multiuser,...
  su - testuser
  cifscreds add -d ZELDA -u testuser
  ...
  ls /mnt/1
  ...
  umount /mnt
  echo scan > /sys/kernel/debug/kmemleak
  cat /sys/kernel/debug/kmemleak
  unreferenced object 0xffff8881203c3f08 (size 8):
    comm "ls", pid 5060, jiffies 4307222943
    hex dump (first 8 bytes):
      5a 45 4c 44 41 00 cc cc                          ZELDA...
    backtrace (crc d109a8cf):
      __kmalloc_node_track_caller_noprof+0x572/0x710
      kstrdup+0x3a/0x70
      cifs_sb_tlink+0x1209/0x1770 [cifs]
      cifs_get_fattr+0xe1/0xf50 [cifs]
      cifs_get_inode_info+0xb5/0x240 [cifs]
      cifs_revalidate_dentry_attr+0x2d1/0x470 [cifs]
      cifs_getattr+0x28e/0x450 [cifs]
      vfs_getattr_nosec+0x126/0x180
      vfs_statx+0xf6/0x220
      do_statx+0xab/0x110
      __x64_sys_statx+0xd5/0x130
      do_syscall_64+0xbb/0x380
      entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: f2aee329a6 ("cifs: set domainName when a domain-key is used in multiuser")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Jay Shin <jaeshin@redhat.com>
Cc: stable@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:18:51 +09:00
2022-09-28 09:02:20 +02:00
2025-12-01 11:41:54 +01:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%