Commit 8ddecf5f authored by Aurelien Aptel's avatar Aurelien Aptel Committed by Steve French
Browse files

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: default avatarAurelien Aptel <aaptel@suse.com>
Reviewed-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
Acked-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
parent 83210ba6

fs/cifs/cifsglob.h

+6 −0
Original line number Diff line number Diff line
@@ -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 *

fs/cifs/connect.c

+0 −6
Original line number Diff line number Diff line
@@ -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)

{

fs/cifs/smb2misc.c

+3 −1
Original line number Diff line number Diff line
@@ -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;

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