ksmbd: fix race condition between session lookup and expire

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commit 53ff5cf891 upstream.

 Thread A                        +  Thread B
 ksmbd_session_lookup            |  smb2_sess_setup
   sess = xa_load                |
                                 |
                                 |    xa_erase(&conn->sessions, sess->id);
                                 |
                                 |    ksmbd_session_destroy(sess) --> kfree(sess)
                                 |
   // UAF!                       |
   sess->last_active = jiffies   |
                                 +

This patch add rwsem to fix race condition between ksmbd_session_lookup
and ksmbd_expire_session.

Reported-by: luosili <rootlab@huawei.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Namjae Jeon 2023-10-04 18:25:01 +09:00 • committed by Greg Kroah-Hartman

parent 64301a9354

commit a2ca5fd3db

3 changed files with 10 additions and 3 deletions

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2

fs/smb/server/connection.c

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1

fs/smb/server/connection.h

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10

fs/smb/server/mgmt/user_session.c

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