From a65f2b56334ba4dc30bd5ee9ce5b2691b973344d Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Tue, 2 Apr 2024 16:33:53 -0300 Subject: [PATCH] smb: client: fix potential UAF in cifs_debug_files_proc_show() commit ca545b7f0823f19db0f1148d59bc5e1a56634502 upstream. Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF. Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/cifs_debug.c | 2 ++ fs/smb/client/cifsglob.h | 10 ++++++++++ 2 files changed, 12 insertions(+) diff --git a/fs/smb/client/cifs_debug.c b/fs/smb/client/cifs_debug.c index 7206167f4184..82cac8169602 100644 --- a/fs/smb/client/cifs_debug.c +++ b/fs/smb/client/cifs_debug.c @@ -250,6 +250,8 @@ static int cifs_debug_files_proc_show(struct seq_file *m, void *v) spin_lock(&cifs_tcp_ses_lock); list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) { list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { + if (cifs_ses_exiting(ses)) + continue; list_for_each_entry(tcon, &ses->tcon_list, tcon_list) { spin_lock(&tcon->open_file_lock); list_for_each_entry(cfile, &tcon->openFileList, tlist) { diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index b99767c8d373..a878b1e5aa31 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -2281,4 +2281,14 @@ struct smb2_compound_vars { struct smb2_file_link_info link_info; }; +static inline bool cifs_ses_exiting(struct cifs_ses *ses) +{ + bool ret; + + spin_lock(&ses->ses_lock); + ret = ses->ses_status == SES_EXITING; + spin_unlock(&ses->ses_lock); + return ret; +} + #endif /* _CIFS_GLOB_H */