From 193cdd8a293007d1a1ad252cf66b2dc5b793d2d0 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 10 Dec 2012 06:10:44 -0500 Subject: [PATCH] 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: Pavel Shilovsky Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifsacl.c | 25 +++++++++++++++++++------ fs/cifs/cifsacl.h | 8 +++++--- 2 files changed, 24 insertions(+), 9 deletions(-) diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c index 8dd9212ffef5..75c1ee699143 100644 --- a/fs/cifs/cifsacl.c +++ b/fs/cifs/cifsacl.c @@ -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]); - strptr += len; - } - } + /* 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]); diff --git a/fs/cifs/cifsacl.h b/fs/cifs/cifsacl.h index a445405f80d0..4f3884835267 100644 --- a/fs/cifs/cifsacl.h +++ b/fs/cifs/cifsacl.h @@ -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 {