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charset: fixed a problem with the global use of the iconv_convenience structure

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We had a crash bug where a cached copy of a iconv convenience pointer
was used after being freed when loadparm asked for iconv to
reload. This could happen if a python module used a iconv based
function before loadparm was completed.

The fix is to ensure that any use of this pointer remains valid, by
reusing the pointer itself when it has already been initialised, but
filling in the child elements with the updated values.
This commit is contained in:
Andrew Tridgell
2010-03-18 14:06:13 +11:00
parent 752b2206cb
commit 55c45110e6
9 changed files with 69 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
lib/util/charset/charcnv.c
View File

@ -39,6 +39,7 @@
*/
struct smb_iconv_convenience {
TALLOC_CTX *child_ctx;
const char *unix_charset;
const char *dos_charset;
bool native_iconv;
@ -83,22 +84,45 @@ static int close_iconv_convenience(struct smb_iconv_convenience *data)
return 0;
}
_PUBLIC_ struct smb_iconv_convenience *smb_iconv_convenience_init(TALLOC_CTX *mem_ctx,
/*
the old_ic is passed in here as the smb_iconv_convenience structure
is used as a global pointer in some places (eg. python modules). We
don't want to invalidate those global pointers, but we do want to
update them with the right charset information when loadparm
runs. To do that we need to re-use the structure pointer, but
re-fill the elements in the structure with the updated values
*/
_PUBLIC_ struct smb_iconv_convenience *smb_iconv_convenience_reinit(TALLOC_CTX *mem_ctx,
const char *dos_charset,
const char *unix_charset,
bool native_iconv)
bool native_iconv,
struct smb_iconv_convenience *old_ic)
{
struct smb_iconv_convenience *ret = talloc_zero(mem_ctx,
struct smb_iconv_convenience);
struct smb_iconv_convenience *ret;
if (old_ic != NULL) {
ret = old_ic;
close_iconv_convenience(ret);
talloc_free(ret->child_ctx);
ZERO_STRUCTP(ret);
} else {
ret = talloc_zero(mem_ctx, struct smb_iconv_convenience);
}
if (ret == NULL) {
return NULL;
}
/* we use a child context to allow us to free all ptrs without
freeing the structure itself */
ret->child_ctx = talloc_new(ret);
if (ret->child_ctx == NULL) {
return NULL;
}
talloc_set_destructor(ret, close_iconv_convenience);
ret->dos_charset = talloc_strdup(ret, dos_charset);
ret->unix_charset = talloc_strdup(ret, unix_charset);
ret->dos_charset = talloc_strdup(ret->child_ctx, dos_charset);
ret->unix_charset = talloc_strdup(ret->child_ctx, unix_charset);
ret->native_iconv = native_iconv;
return ret;

5
lib/util/charset/charset.h
View File

@ -163,10 +163,11 @@ codepoint_t tolower_m(codepoint_t val);
int codepoint_cmpi(codepoint_t c1, codepoint_t c2);
/* Iconv convenience functions */
struct smb_iconv_convenience *smb_iconv_convenience_init(TALLOC_CTX *mem_ctx,
struct smb_iconv_convenience *smb_iconv_convenience_reinit(TALLOC_CTX *mem_ctx,
const char *dos_charset,
const char *unix_charset,
bool native_iconv);
bool native_iconv,
struct smb_iconv_convenience *old_ic);
bool convert_string_convenience(struct smb_iconv_convenience *ic,
charset_t from, charset_t to,

3
lib/util/charset/util_unistr.c
View File

@ -26,7 +26,8 @@ struct smb_iconv_convenience *global_iconv_convenience = NULL;
static inline struct smb_iconv_convenience *get_iconv_convenience(void)
{
if (global_iconv_convenience == NULL)
global_iconv_convenience = smb_iconv_convenience_init(talloc_autofree_context(), "ASCII", "UTF-8", true);
global_iconv_convenience = smb_iconv_convenience_reinit(talloc_autofree_context(),
"ASCII", "UTF-8", true, NULL);
return global_iconv_convenience;
}

6
librpc/ndr/ndr.c
View File

@ -260,7 +260,8 @@ _PUBLIC_ void ndr_print_function_debug(ndr_print_function_t fn, const char *name
* this all the way down
*/
#if _SAMBA_BUILD_ == 4
ndr->iconv_convenience = smb_iconv_convenience_init(talloc_autofree_context(), "ASCII", "UTF-8", true);
ndr->iconv_convenience = smb_iconv_convenience_reinit(talloc_autofree_context(),
"ASCII", "UTF-8", true, NULL);
#endif
fn(ndr, name, flags, ptr);
@ -289,7 +290,8 @@ _PUBLIC_ char *ndr_print_struct_string(TALLOC_CTX *mem_ctx, ndr_print_fn_t fn, c
* this all the way down
*/
#if _SAMBA_BUILD_ == 4
ndr->iconv_convenience = smb_iconv_convenience_init(talloc_autofree_context(), "ASCII", "UTF-8", true);
ndr->iconv_convenience = smb_iconv_convenience_reinit(talloc_autofree_context(),
"ASCII", "UTF-8", true, NULL);
#endif
fn(ndr, name, ptr);

12
pidl/tests/ndr_string.pl
View File

@ -15,7 +15,7 @@ test_samba4_ndr("string-pull-empty",
uint8_t data[] = { 0x00, 0x00, 0x00, 0x00 };
DATA_BLOB b = { data, 4 };
struct ndr_pull *ndr = ndr_pull_init_blob(&b, NULL,
smb_iconv_convenience_init(NULL, "ASCII", "UTF8", true));
smb_iconv_convenience_reinit(NULL, "ASCII", "UTF8", true, NULL));
struct TestString r;
r.in.data = NULL;
@ -38,7 +38,7 @@ test_samba4_ndr("string-ascii-pull",
\'f\', \'o\', \'o\', 0 };
DATA_BLOB b = { data, 8 };
struct ndr_pull *ndr = ndr_pull_init_blob(&b, NULL,
smb_iconv_convenience_init(NULL, "ASCII", "UTF8", true));
smb_iconv_convenience_reinit(NULL, "ASCII", "UTF8", true, NULL));
struct TestString r;
r.in.data = NULL;
@ -75,7 +75,7 @@ test_samba4_ndr("string-wchar-fixed-array-01",
};
DATA_BLOB b = { data, sizeof(data) };
struct ndr_pull *ndr = ndr_pull_init_blob(&b, NULL,
smb_iconv_convenience_init(NULL, "ASCII", "UTF8", true));
smb_iconv_convenience_reinit(NULL, "ASCII", "UTF8", true, NULL));
struct TestString r;
struct TestStringStruct str;
r.in.str = &str;
@ -121,7 +121,7 @@ test_samba4_ndr("string-wchar-fixed-array-02",
};
DATA_BLOB b = { data, sizeof(data) };
struct ndr_pull *ndr = ndr_pull_init_blob(&b, NULL,
smb_iconv_convenience_init(NULL, "ASCII", "UTF8", true));
smb_iconv_convenience_reinit(NULL, "ASCII", "UTF8", true, NULL));
struct TestString r;
struct TestStringStruct str;
r.in.str = &str;
@ -153,7 +153,7 @@ test_samba4_ndr("string-wchar-fixed-array-03",
};
DATA_BLOB b = { data, sizeof(data) };
struct ndr_pull *ndr = ndr_pull_init_blob(&b, NULL,
smb_iconv_convenience_init(NULL, "ASCII", "UTF8", true));
smb_iconv_convenience_reinit(NULL, "ASCII", "UTF8", true, NULL));
struct TestString r;
struct TestStringStruct str;
r.in.str = &str;
@ -175,7 +175,7 @@ test_samba4_ndr("string-out",
\'f\', \'o\', \'o\', 0 };
DATA_BLOB b = { data, 8 };
struct ndr_pull *ndr = ndr_pull_init_blob(&b, NULL,
smb_iconv_convenience_init(NULL, "ASCII", "UTF8", true));
smb_iconv_convenience_reinit(NULL, "ASCII", "UTF8", true, NULL));
struct TestString r;
char *str = NULL;
r.out.data = &str;

12
source4/param/loadparm.c
View File

@ -2692,8 +2692,8 @@ struct smb_iconv_convenience *lp_iconv_convenience(struct loadparm_context *lp_c
if (lp_ctx == NULL) {
static struct smb_iconv_convenience *fallback_ic = NULL;
if (fallback_ic == NULL)
fallback_ic = smb_iconv_convenience_init(talloc_autofree_context(),
"CP850", "UTF8", true);
fallback_ic = smb_iconv_convenience_reinit(talloc_autofree_context(),
"CP850", "UTF8", true, NULL);
return fallback_ic;
}
return lp_ctx->iconv_convenience;
@ -2701,8 +2701,12 @@ struct smb_iconv_convenience *lp_iconv_convenience(struct loadparm_context *lp_c
_PUBLIC_ void reload_charcnv(struct loadparm_context *lp_ctx)
{
talloc_unlink(lp_ctx, lp_ctx->iconv_convenience);
global_iconv_convenience = lp_ctx->iconv_convenience = smb_iconv_convenience_init_lp(lp_ctx, lp_ctx);
struct smb_iconv_convenience *old_ic = lp_ctx->iconv_convenience;
if (old_ic == NULL) {
old_ic = global_iconv_convenience;
}
lp_ctx->iconv_convenience = smb_iconv_convenience_reinit_lp(lp_ctx, lp_ctx, old_ic);
global_iconv_convenience = lp_ctx->iconv_convenience;
}
void lp_smbcli_options(struct loadparm_context *lp_ctx,

5
source4/param/param.h
View File

@ -438,8 +438,9 @@ bool run_init_functions(init_module_fn *fns);
init_module_fn *load_samba_modules(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx, const char *subsystem);
const char *lp_messaging_path(TALLOC_CTX *mem_ctx,
struct loadparm_context *lp_ctx);
struct smb_iconv_convenience *smb_iconv_convenience_init_lp(TALLOC_CTX *mem_ctx,
struct loadparm_context *lp_ctx);
struct smb_iconv_convenience *smb_iconv_convenience_reinit_lp(TALLOC_CTX *mem_ctx,
struct loadparm_context *lp_ctx,
struct smb_iconv_convenience *old_ic);
const char *lp_sam_name(struct loadparm_context *lp_ctx);

10
source4/param/util.c
View File

@ -299,12 +299,14 @@ const char *lp_messaging_path(TALLOC_CTX *mem_ctx,
return smbd_tmp_path(mem_ctx, lp_ctx, "messaging");
}
struct smb_iconv_convenience *smb_iconv_convenience_init_lp(TALLOC_CTX *mem_ctx,
struct loadparm_context *lp_ctx)
struct smb_iconv_convenience *smb_iconv_convenience_reinit_lp(TALLOC_CTX *mem_ctx,
struct loadparm_context *lp_ctx,
struct smb_iconv_convenience *old_ic)
{
return smb_iconv_convenience_init(mem_ctx, lp_dos_charset(lp_ctx),
return smb_iconv_convenience_reinit(mem_ctx, lp_dos_charset(lp_ctx),
lp_unix_charset(lp_ctx),
lp_parm_bool(lp_ctx, NULL, "iconv", "native", true));
lp_parm_bool(lp_ctx, NULL, "iconv", "native", true),
old_ic);
}

3
source4/scripting/python/modules.h
View File

@ -23,6 +23,7 @@
void py_load_samba_modules(void);
bool py_update_path(const char *bindir);
#define py_iconv_convenience(mem_ctx) smb_iconv_convenience_init(mem_ctx, "ASCII", PyUnicode_GetDefaultEncoding(), true)
#define py_iconv_convenience(mem_ctx) smb_iconv_convenience_reinit(mem_ctx, "ASCII", \
PyUnicode_GetDefaultEncoding(), true, NULL)
#endif /* __SAMBA_PYTHON_MODULES_H__ */