Nikolay Sivov : ntdll: While requesting TokenGroups calculate required user buffer size in server .
Module: wine Branch: master Commit: 573db9ef639f65385f1efab5593b52c72b4b4108 URL: http://source.winehq.org/git/wine.git/?a=commit;h=573db9ef639f65385f1efab559... Author: Nikolay Sivov <nsivov(a)codeweavers.com> Date: Tue Aug 23 11:16:27 2011 +0400 ntdll: While requesting TokenGroups calculate required user buffer size in server. --- dlls/advapi32/tests/security.c | 18 ++++++++ dlls/ntdll/nt.c | 92 ++++++++++++++++------------------------ server/token.c | 17 ++++++- 3 files changed, 68 insertions(+), 59 deletions(-) diff --git a/dlls/advapi32/tests/security.c b/dlls/advapi32/tests/security.c index 17c52dc..336cc9c 100644 --- a/dlls/advapi32/tests/security.c +++ b/dlls/advapi32/tests/security.c @@ -1442,6 +1442,24 @@ static void test_token_attr(void) ok(ret, "OpenProcessToken failed with error %d\n", GetLastError()); /* groups */ + /* insufficient buffer length */ + SetLastError(0xdeadbeef); + Size2 = 0; + ret = GetTokenInformation(Token, TokenGroups, NULL, 0, &Size2); + ok(Size2 > 1, "got %d\n", Size2); + ok(!ret && GetLastError() == ERROR_INSUFFICIENT_BUFFER, + "%d with error %d\n", ret, GetLastError()); + Size2 -= 1; + Groups = HeapAlloc(GetProcessHeap(), 0, Size2); + memset(Groups, 0xcc, Size2); + Size = 0; + ret = GetTokenInformation(Token, TokenGroups, Groups, Size2, &Size); + ok(Size > 1, "got %d\n", Size); + ok(!ret && GetLastError() == ERROR_INSUFFICIENT_BUFFER, + "%d with error %d\n", ret, GetLastError()); + ok(*((BYTE*)Groups) == 0xcc, "buffer altered\n"); + HeapFree(GetProcessHeap(), 0, Groups); + SetLastError(0xdeadbeef); ret = GetTokenInformation(Token, TokenGroups, NULL, 0, &Size); ok(!ret && GetLastError() == ERROR_INSUFFICIENT_BUFFER, diff --git a/dlls/ntdll/nt.c b/dlls/ntdll/nt.c index 3e5d420..83a341f 100644 --- a/dlls/ntdll/nt.c +++ b/dlls/ntdll/nt.c @@ -320,68 +320,48 @@ NTSTATUS WINAPI NtQueryInformationToken( break; case TokenGroups: { - char stack_buffer[256]; - unsigned int server_buf_len = sizeof(stack_buffer); - void *buffer = stack_buffer; - BOOLEAN need_more_memory; - - /* we cannot work out the size of the server buffer required for the - * input size, since there are two factors affecting how much can be - * stored in the buffer - number of groups and lengths of sids */ - do + void *buffer; + + /* reply buffer is always shorter than output one */ + buffer = tokeninfolength ? RtlAllocateHeap(GetProcessHeap(), 0, tokeninfolength) : NULL; + + SERVER_START_REQ( get_token_groups ) { - need_more_memory = FALSE; + TOKEN_GROUPS *groups = tokeninfo; - SERVER_START_REQ( get_token_groups ) + req->handle = wine_server_obj_handle( token ); + wine_server_set_reply( req, buffer, tokeninfolength ); + status = wine_server_call( req ); + if (status == STATUS_BUFFER_TOO_SMALL) { - TOKEN_GROUPS *groups = tokeninfo; - - req->handle = wine_server_obj_handle( token ); - wine_server_set_reply( req, buffer, server_buf_len ); - status = wine_server_call( req ); - if (status == STATUS_BUFFER_TOO_SMALL) - { - if (buffer == stack_buffer) - buffer = RtlAllocateHeap(GetProcessHeap(), 0, reply->user_len); - else - buffer = RtlReAllocateHeap(GetProcessHeap(), 0, buffer, reply->user_len); - if (!buffer) return STATUS_NO_MEMORY; - - server_buf_len = reply->user_len; - need_more_memory = TRUE; - } - else if (status == STATUS_SUCCESS) - { - struct token_groups *tg = buffer; - unsigned int *attr = (unsigned int *)(tg + 1); - ULONG i; - const int non_sid_portion = (sizeof(struct token_groups) + tg->count * sizeof(unsigned int)); - SID *sids = (SID *)((char *)tokeninfo + FIELD_OFFSET( TOKEN_GROUPS, Groups[tg->count] )); - ULONG needed_bytes = FIELD_OFFSET( TOKEN_GROUPS, Groups[tg->count] ) + - reply->user_len - non_sid_portion; + if (retlen) *retlen = reply->user_len; + } + else if (status == STATUS_SUCCESS) + { + struct token_groups *tg = buffer; + unsigned int *attr = (unsigned int *)(tg + 1); + ULONG i; + const int non_sid_portion = (sizeof(struct token_groups) + tg->count * sizeof(unsigned int)); + SID *sids = (SID *)((char *)tokeninfo + FIELD_OFFSET( TOKEN_GROUPS, Groups[tg->count] )); - if (retlen) *retlen = needed_bytes; + if (retlen) *retlen = reply->user_len; - if (needed_bytes <= tokeninfolength) - { - groups->GroupCount = tg->count; - memcpy( sids, (char *)buffer + non_sid_portion, - reply->user_len - non_sid_portion ); + groups->GroupCount = tg->count; + memcpy( sids, (char *)buffer + non_sid_portion, + reply->user_len - non_sid_portion - FIELD_OFFSET( TOKEN_GROUPS, Groups[tg->count] )); - for (i = 0; i < tg->count; i++) - { - groups->Groups[i].Attributes = attr[i]; - groups->Groups[i].Sid = sids; - sids = (SID *)((char *)sids + RtlLengthSid(sids)); - } - } - else status = STATUS_BUFFER_TOO_SMALL; + for (i = 0; i < tg->count; i++) + { + groups->Groups[i].Attributes = attr[i]; + groups->Groups[i].Sid = sids; + sids = (SID *)((char *)sids + RtlLengthSid(sids)); } - else if (retlen) *retlen = 0; - } - SERVER_END_REQ; - } while (need_more_memory); - if (buffer != stack_buffer) RtlFreeHeap(GetProcessHeap(), 0, buffer); + } + else if (retlen) *retlen = 0; + } + SERVER_END_REQ; + + RtlFreeHeap(GetProcessHeap(), 0, buffer); break; } case TokenPrimaryGroup: diff --git a/server/token.c b/server/token.c index ab07a81..a0ec143 100644 --- a/server/token.c +++ b/server/token.c @@ -1295,19 +1295,30 @@ DECL_HANDLER(get_token_groups) &token_ops ))) { size_t size_needed = sizeof(struct token_groups); + size_t sid_size = 0; unsigned int group_count = 0; const struct group *group; LIST_FOR_EACH_ENTRY( group, &token->groups, const struct group, entry ) { group_count++; - size_needed += FIELD_OFFSET(SID, SubAuthority[group->sid.SubAuthorityCount]); + sid_size += FIELD_OFFSET(SID, SubAuthority[group->sid.SubAuthorityCount]); } + size_needed += sid_size; + /* attributes size */ size_needed += sizeof(unsigned int) * group_count; - reply->user_len = size_needed; + /* reply buffer contains size_needed bytes formatted as: - if (size_needed <= get_reply_max_size()) + unsigned int count; + unsigned int attrib[count]; + char sid_data[]; + + user_len includes extra data needed for TOKEN_GROUPS representation, + required caller buffer size calculated here to avoid extra server call */ + reply->user_len = FIELD_OFFSET( TOKEN_GROUPS, Groups[group_count] ) + sid_size; + + if (reply->user_len <= get_reply_max_size()) { struct token_groups *tg = set_reply_data_size( size_needed ); if (tg)
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Alexandre Julliard