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Commit 193cdd8a authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

cifs: fix SID binary to string conversion 



The authority fields are supposed to be represented by a single 48-bit
value. It's also supposed to represent the value as hex if it's equal to
or greater than 2^32. This is documented in MS-DTYP, section 2.4.2.1.

Also, fix up the max string length to account for this fix.

Acked-by: default avatarPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent 6d8b59d7

fs/cifs/cifsacl.c

+19 −6
Original line number Diff line number Diff line
@@ -94,6 +94,7 @@ sid_to_key_str(struct cifs_sid *sidptr, unsigned int type) 
	int i, len;

	unsigned int saval;

	char *sidstr, *strptr;

	unsigned long long id_auth_val;



	/* 3 bytes for prefix */

	sidstr = kmalloc(3 + SID_STRING_BASE_SIZE +
@@ -107,12 +108,24 @@ sid_to_key_str(struct cifs_sid *sidptr, unsigned int type) 
			sidptr->revision);

	strptr += len;



	for (i = 0; i < NUM_AUTHS; ++i) {

		if (sidptr->authority[i]) {

			len = sprintf(strptr, "-%hhu", sidptr->authority[i]);

	/* The authority field is a single 48-bit number */

	id_auth_val = (unsigned long long)sidptr->authority[5];

	id_auth_val |= (unsigned long long)sidptr->authority[4] << 8;

	id_auth_val |= (unsigned long long)sidptr->authority[3] << 16;

	id_auth_val |= (unsigned long long)sidptr->authority[2] << 24;

	id_auth_val |= (unsigned long long)sidptr->authority[1] << 32;

	id_auth_val |= (unsigned long long)sidptr->authority[0] << 48;



	/*

	 * MS-DTYP states that if the authority is >= 2^32, then it should be

	 * expressed as a hex value.

	 */

	if (id_auth_val <= UINT_MAX)

		len = sprintf(strptr, "-%llu", id_auth_val);

	else

		len = sprintf(strptr, "-0x%llx", id_auth_val);



	strptr += len;

		}

	}



	for (i = 0; i < sidptr->num_subauth; ++i) {

		saval = le32_to_cpu(sidptr->sub_auth[i]);

fs/cifs/cifsacl.h

+5 −3
Original line number Diff line number Diff line
@@ -55,12 +55,14 @@ 
 * u8:  max 3 bytes in decimal

 * u32: max 10 bytes in decimal

 *

 * "S-" + 3 bytes for version field + 4 bytes for each authority field (3 bytes

 * per number + 1 for '-') + NULL terminator.

 * "S-" + 3 bytes for version field + 15 for authority field + NULL terminator

 *

 * For authority field, max is when all 6 values are non-zero and it must be

 * represented in hex. So "-0x" + 12 hex digits.

 *

 * Add 11 bytes for each subauthority field (10 bytes each + 1 for '-')

 */

#define SID_STRING_BASE_SIZE (2 + 3 + (4 * NUM_AUTHS) + 1)

#define SID_STRING_BASE_SIZE (2 + 3 + 15 + 1)

#define SID_STRING_SUBAUTH_SIZE (11) /* size of a single subauth string */



struct cifs_ntsd {