[CIFS] Fix acl length when very short ACL being modified by chmod (cce246ee) · Commits · e / devices / android_kernel_fairphone_FP3

fs/cifs/cifsacl.c

+8 −6

Original line number	Original line	Diff line number	Diff line
	@@ -516,7 +516,7 @@ static int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len,

	/* Convert permission bits from mode to equivalent CIFS ACL */		/* Convert permission bits from mode to equivalent CIFS ACL */
	static int build_sec_desc(struct cifs_ntsd pntsd, struct cifs_ntsd pnntsd,		static int build_sec_desc(struct cifs_ntsd pntsd, struct cifs_ntsd pnntsd,
	int acl_len, struct inode *inode, __u64 nmode)		struct inode *inode, __u64 nmode)
	{		{
	int rc = 0;		int rc = 0;
	__u32 dacloffset;		__u32 dacloffset;
	@@ -692,14 +692,14 @@ void acl_to_uid_mode(struct inode inode, const char path, const __u16 *pfid)
	int mode_to_acl(struct inode inode, const char path, __u64 nmode)		int mode_to_acl(struct inode inode, const char path, __u64 nmode)
	{		{
	int rc = 0;		int rc = 0;
	__u32 acllen = 0;		__u32 secdesclen = 0;
	struct cifs_ntsd pntsd = NULL; / acl obtained from server */		struct cifs_ntsd pntsd = NULL; / acl obtained from server */
	struct cifs_ntsd pnntsd = NULL; / modified acl to be sent to server */		struct cifs_ntsd pnntsd = NULL; / modified acl to be sent to server */

	cFYI(DBG2, ("set ACL from mode for %s", path));		cFYI(DBG2, ("set ACL from mode for %s", path));

	/* Get the security descriptor */		/* Get the security descriptor */
	pntsd = get_cifs_acl(&acllen, inode, path, NULL);		pntsd = get_cifs_acl(&secdesclen, inode, path, NULL);

	/* Add three ACEs for owner, group, everyone getting rid of		/* Add three ACEs for owner, group, everyone getting rid of
	other ACEs as chmod disables ACEs and set the security descriptor */		other ACEs as chmod disables ACEs and set the security descriptor */
	@@ -709,20 +709,22 @@ int mode_to_acl(struct inode inode, const char path, __u64 nmode)
	set security descriptor request security descriptor		set security descriptor request security descriptor
	parameters, and secuirty descriptor itself */		parameters, and secuirty descriptor itself */

	pnntsd = kmalloc(acllen, GFP_KERNEL);		secdesclen = secdesclen < DEFSECDESCLEN ?
			DEFSECDESCLEN : secdesclen;
			pnntsd = kmalloc(secdesclen, GFP_KERNEL);
	if (!pnntsd) {		if (!pnntsd) {
	cERROR(1, ("Unable to allocate security descriptor"));		cERROR(1, ("Unable to allocate security descriptor"));
	kfree(pntsd);		kfree(pntsd);
	return (-ENOMEM);		return (-ENOMEM);
	}		}

	rc = build_sec_desc(pntsd, pnntsd, acllen, inode, nmode);		rc = build_sec_desc(pntsd, pnntsd, inode, nmode);

	cFYI(DBG2, ("build_sec_desc rc: %d", rc));		cFYI(DBG2, ("build_sec_desc rc: %d", rc));

	if (!rc) {		if (!rc) {
	/* Set the security descriptor */		/* Set the security descriptor */
	rc = set_cifs_acl(pnntsd, acllen, inode, path);		rc = set_cifs_acl(pnntsd, secdesclen, inode, path);
	cFYI(DBG2, ("set_cifs_acl rc: %d", rc));		cFYI(DBG2, ("set_cifs_acl rc: %d", rc));
	}		}

fs/cifs/cifsacl.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -27,6 +27,7 @@
	#define NUM_SUBAUTHS 5 /* number of sub authority fields */		#define NUM_SUBAUTHS 5 /* number of sub authority fields */
	#define NUM_WK_SIDS 7 /* number of well known sids */		#define NUM_WK_SIDS 7 /* number of well known sids */
	#define SIDNAMELENGTH 20 /* long enough for the ones we care about */		#define SIDNAMELENGTH 20 /* long enough for the ones we care about */
			#define DEFSECDESCLEN 192 /* sec desc len contaiting a dacl with three aces */

	#define READ_BIT 0x4		#define READ_BIT 0x4
	#define WRITE_BIT 0x2		#define WRITE_BIT 0x2