From 8ddecf5fd728d3c6373394fa647d28e7c27f93a7 Mon Sep 17 00:00:00 2001 From: Aurelien Aptel Date: Mon, 4 Jun 2018 22:29:35 +0200 Subject: [PATCH] CIFS: Fix NULL ptr deref cifs->master_tlink is NULL against Win Server 2016 (which is strange.. not sure why) and is dereferenced in cifs_sb_master_tcon(). move master_tlink getter to cifsglob.h so it can be used from smb2misc.c Signed-off-by: Aurelien Aptel Reviewed-by: Ronnie Sahlberg Signed-off-by: Steve French Acked-by: Pavel Shilovsky --- fs/cifs/cifsglob.h | 6 ++++++ fs/cifs/connect.c | 6 ------ fs/cifs/smb2misc.c | 4 +++- 3 files changed, 9 insertions(+), 7 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 08d1cdd96701..1efa2e65bc1a 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1019,6 +1019,12 @@ tlink_tcon(struct tcon_link *tlink) return tlink->tl_tcon; } +static inline struct tcon_link * +cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb) +{ + return cifs_sb->master_tlink; +} + extern void cifs_put_tlink(struct tcon_link *tlink); static inline struct tcon_link * diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index e5a2fe7f0dd4..9089b73809de 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3116,12 +3116,6 @@ cifs_put_tlink(struct tcon_link *tlink) return; } -static inline struct tcon_link * -cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb) -{ - return cifs_sb->master_tlink; -} - static int compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data) { diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index cb5728e3d87d..e2bec47c6845 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -453,8 +453,10 @@ cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb) start_of_path = from + 1; #ifdef CONFIG_CIFS_SMB311 /* SMB311 POSIX extensions paths do not include leading slash */ - else if (cifs_sb_master_tcon(cifs_sb)->posix_extensions) + else if (cifs_sb_master_tlink(cifs_sb) && + cifs_sb_master_tcon(cifs_sb)->posix_extensions) { start_of_path = from + 1; + } #endif /* 311 */ else start_of_path = from; -- GitLab