| Message ID | 20210813115157.789302-1-jwcart2@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | libsepol/cil: Allow some duplicate macro and block declarations | expand |
Sorry, didn't mean to send this patch again. Jim On Fri, Aug 13, 2021 at 7:52 AM James Carter <jwcart2@gmail.com> wrote: > > The commit d155b410d4bbc90d28f361b966f0429598da8188 (libsepol/cil: > Check for duplicate blocks, optionals, and macros) added checks when > copying blocks, macros, and optionals so that a duplicate would cause > an exit with an error. Unfortunately, some policies exist that depend > on this behavior when using inheritance. > > The behavior is as follows. > > For macros only the first declared macro matters. > ; > (macro m ((type ARG1)) > (allow ARG1 self (CLASS (PERM1))) > ) > (block b > (macro m ((type ARG1)) > (allow ARG1 self (CLASS (PERM2))) > ) > ) > (blockinherit b) > (type t) > (call m (t)) > ; > For this policy segment, the macro m in block b will not be called. > Only the original macro m will be. > > This behavior has been used to override macros that are going to > be inherited. Only the inherited macros that have not already been > declared in the destination namespace will be used. > > Blocks seem to work fine even though there are two of them > ; > (block b1 > (blockinherit b2) > (block b > (type t1) > (allow t1 self (CLASS (PERM))) > ) > ) > (block b2 > (block b > (type t2) > (allow t2 self (CLASS (PERM))) > ) > ) > (blockinherit b1) > ; > In this example, the blockinherit of b2 will cause there to be > two block b's in block b1. Note that if both block b's tried to > declare the same type, then that would be an error. The blockinherit > of b1 will copy both block b's. > > This behavior has been used to allow the use of in-statements for > a block that is being inherited. Since the in-statements are resolved > before block inheritance, this only works if a block with the same > name as the block to be inherited is declared in the namespace. > > To support the use of these two behaviors, allow duplicate blocks > and macros when they occur as the result of block inheritance. In > any other circumstances and error for a redeclaration will be given. > > Since the duplicate macro is not going to be used it is just skipped. > The duplicate block will use the datum of the original block. In both > cases a warning message will be produced (it will only be seen if > "-v" is used when compiling the policy). > > Signed-off-by: James Carter <jwcart2@gmail.com> > --- > libsepol/cil/src/cil_copy_ast.c | 69 ++++++++++++++++++++++++--------- > 1 file changed, 50 insertions(+), 19 deletions(-) > > diff --git a/libsepol/cil/src/cil_copy_ast.c b/libsepol/cil/src/cil_copy_ast.c > index 9c0231f2..67be2ec8 100644 > --- a/libsepol/cil/src/cil_copy_ast.c > +++ b/libsepol/cil/src/cil_copy_ast.c > @@ -43,6 +43,7 @@ > #include "cil_verify.h" > > struct cil_args_copy { > + struct cil_tree_node *orig_dest; > struct cil_tree_node *dest; > struct cil_db *db; > }; > @@ -101,17 +102,23 @@ int cil_copy_block(__attribute__((unused)) struct cil_db *db, void *data, void * > struct cil_block *orig = data; > char *key = orig->datum.name; > struct cil_symtab_datum *datum = NULL; > - struct cil_block *new; > > cil_symtab_get_datum(symtab, key, &datum); > if (datum != NULL) { > - cil_tree_log(NODE(datum), CIL_ERR, "Re-declaration of %s %s", cil_node_to_string(NODE(datum)), key); > - return SEPOL_ERR; > + if (FLAVOR(datum) != CIL_BLOCK) { > + cil_tree_log(NODE(orig), CIL_ERR, "Block %s being copied", key); > + cil_tree_log(NODE(datum), CIL_ERR, " Conflicts with %s already declared", cil_node_to_string(NODE(datum))); > + return SEPOL_ERR; > + } > + cil_tree_log(NODE(orig), CIL_WARN, "Block %s being copied", key); > + cil_tree_log(NODE(datum), CIL_WARN, " Previously declared", key); > + *copy = datum; > + } else { > + struct cil_block *new; > + cil_block_init(&new); > + *copy = new; > } > > - cil_block_init(&new); > - *copy = new; > - > return SEPOL_OK; > } > > @@ -1511,21 +1518,26 @@ int cil_copy_macro(__attribute__((unused)) struct cil_db *db, void *data, void * > struct cil_macro *orig = data; > char *key = orig->datum.name; > struct cil_symtab_datum *datum = NULL; > - struct cil_macro *new; > > cil_symtab_get_datum(symtab, key, &datum); > if (datum != NULL) { > - cil_tree_log(NODE(datum), CIL_ERR, "Re-declaration of %s %s", cil_node_to_string(NODE(datum)), key); > - return SEPOL_ERR; > - } > - > - cil_macro_init(&new); > - if (orig->params != NULL) { > - cil_copy_list(orig->params, &new->params); > + if (FLAVOR(datum) != CIL_MACRO) { > + cil_tree_log(NODE(orig), CIL_ERR, "Macro %s being copied", key); > + cil_tree_log(NODE(datum), CIL_ERR, " Conflicts with %s already declared", cil_node_to_string(NODE(datum))); > + return SEPOL_ERR; > + } > + cil_tree_log(NODE(orig), CIL_WARN, "Skipping macro %s", key); > + cil_tree_log(NODE(datum), CIL_WARN, " Previously declared"); > + *copy = NULL; > + } else { > + struct cil_macro *new; > + cil_macro_init(&new); > + if (orig->params != NULL) { > + cil_copy_list(orig->params, &new->params); > + } > + *copy = new; > } > > - *copy = new; > - > return SEPOL_OK; > } > > @@ -1700,7 +1712,7 @@ int cil_copy_src_info(__attribute__((unused)) struct cil_db *db, void *data, voi > return SEPOL_OK; > } > > -int __cil_copy_node_helper(struct cil_tree_node *orig, __attribute__((unused)) uint32_t *finished, void *extra_args) > +int __cil_copy_node_helper(struct cil_tree_node *orig, uint32_t *finished, void *extra_args) > { > int rc = SEPOL_ERR; > struct cil_tree_node *parent = NULL; > @@ -2005,6 +2017,16 @@ int __cil_copy_node_helper(struct cil_tree_node *orig, __attribute__((unused)) u > > rc = (*copy_func)(db, orig->data, &data, symtab); > if (rc == SEPOL_OK) { > + if (orig->flavor == CIL_MACRO && data == NULL) { > + /* Skipping macro re-declaration */ > + if (args->orig_dest->flavor != CIL_BLOCKINHERIT) { > + cil_log(CIL_ERR, " Re-declaration of macro is only allowed when inheriting a block\n"); > + return SEPOL_ERR; > + } > + *finished = CIL_TREE_SKIP_HEAD; > + return SEPOL_OK; > + } > + > cil_tree_node_init(&new); > > new->parent = parent; > @@ -2013,7 +2035,15 @@ int __cil_copy_node_helper(struct cil_tree_node *orig, __attribute__((unused)) u > new->flavor = orig->flavor; > new->data = data; > > - if (orig->flavor >= CIL_MIN_DECLARATIVE) { > + if (orig->flavor == CIL_BLOCK && DATUM(data)->nodes->head != NULL) { > + /* Duplicate block */ > + if (args->orig_dest->flavor != CIL_BLOCKINHERIT) { > + cil_log(CIL_ERR, " Re-declaration of block is only allowed when inheriting a block\n"); > + rc = SEPOL_ERR; > + goto exit; > + } > + cil_list_append(DATUM(new->data)->nodes, CIL_NODE, new); > + } else if (orig->flavor >= CIL_MIN_DECLARATIVE) { > /* Check the flavor of data if was found in the destination symtab */ > if (DATUM(data)->nodes->head && FLAVOR(data) != orig->flavor) { > cil_tree_log(orig, CIL_ERR, "Incompatible flavor when trying to copy %s", DATUM(data)->name); > @@ -2098,12 +2128,13 @@ int cil_copy_ast(struct cil_db *db, struct cil_tree_node *orig, struct cil_tree_ > int rc = SEPOL_ERR; > struct cil_args_copy extra_args; > > + extra_args.orig_dest = dest; > extra_args.dest = dest; > extra_args.db = db; > > rc = cil_tree_walk(orig, __cil_copy_node_helper, NULL, __cil_copy_last_child_helper, &extra_args); > if (rc != SEPOL_OK) { > - cil_log(CIL_INFO, "cil_tree_walk failed, rc: %d\n", rc); > + cil_tree_log(dest, CIL_ERR, "Failed to copy %s to %s", cil_node_to_string(orig), cil_node_to_string(dest)); > goto exit; > } > > -- > 2.31.1 >
diff --git a/libsepol/cil/src/cil_copy_ast.c b/libsepol/cil/src/cil_copy_ast.c index 9c0231f2..67be2ec8 100644 --- a/libsepol/cil/src/cil_copy_ast.c +++ b/libsepol/cil/src/cil_copy_ast.c @@ -43,6 +43,7 @@ #include "cil_verify.h" struct cil_args_copy { + struct cil_tree_node *orig_dest; struct cil_tree_node *dest; struct cil_db *db; }; @@ -101,17 +102,23 @@ int cil_copy_block(__attribute__((unused)) struct cil_db *db, void *data, void * struct cil_block *orig = data; char *key = orig->datum.name; struct cil_symtab_datum *datum = NULL; - struct cil_block *new; cil_symtab_get_datum(symtab, key, &datum); if (datum != NULL) { - cil_tree_log(NODE(datum), CIL_ERR, "Re-declaration of %s %s", cil_node_to_string(NODE(datum)), key); - return SEPOL_ERR; + if (FLAVOR(datum) != CIL_BLOCK) { + cil_tree_log(NODE(orig), CIL_ERR, "Block %s being copied", key); + cil_tree_log(NODE(datum), CIL_ERR, " Conflicts with %s already declared", cil_node_to_string(NODE(datum))); + return SEPOL_ERR; + } + cil_tree_log(NODE(orig), CIL_WARN, "Block %s being copied", key); + cil_tree_log(NODE(datum), CIL_WARN, " Previously declared", key); + *copy = datum; + } else { + struct cil_block *new; + cil_block_init(&new); + *copy = new; } - cil_block_init(&new); - *copy = new; - return SEPOL_OK; } @@ -1511,21 +1518,26 @@ int cil_copy_macro(__attribute__((unused)) struct cil_db *db, void *data, void * struct cil_macro *orig = data; char *key = orig->datum.name; struct cil_symtab_datum *datum = NULL; - struct cil_macro *new; cil_symtab_get_datum(symtab, key, &datum); if (datum != NULL) { - cil_tree_log(NODE(datum), CIL_ERR, "Re-declaration of %s %s", cil_node_to_string(NODE(datum)), key); - return SEPOL_ERR; - } - - cil_macro_init(&new); - if (orig->params != NULL) { - cil_copy_list(orig->params, &new->params); + if (FLAVOR(datum) != CIL_MACRO) { + cil_tree_log(NODE(orig), CIL_ERR, "Macro %s being copied", key); + cil_tree_log(NODE(datum), CIL_ERR, " Conflicts with %s already declared", cil_node_to_string(NODE(datum))); + return SEPOL_ERR; + } + cil_tree_log(NODE(orig), CIL_WARN, "Skipping macro %s", key); + cil_tree_log(NODE(datum), CIL_WARN, " Previously declared"); + *copy = NULL; + } else { + struct cil_macro *new; + cil_macro_init(&new); + if (orig->params != NULL) { + cil_copy_list(orig->params, &new->params); + } + *copy = new; } - *copy = new; - return SEPOL_OK; } @@ -1700,7 +1712,7 @@ int cil_copy_src_info(__attribute__((unused)) struct cil_db *db, void *data, voi return SEPOL_OK; } -int __cil_copy_node_helper(struct cil_tree_node *orig, __attribute__((unused)) uint32_t *finished, void *extra_args) +int __cil_copy_node_helper(struct cil_tree_node *orig, uint32_t *finished, void *extra_args) { int rc = SEPOL_ERR; struct cil_tree_node *parent = NULL; @@ -2005,6 +2017,16 @@ int __cil_copy_node_helper(struct cil_tree_node *orig, __attribute__((unused)) u rc = (*copy_func)(db, orig->data, &data, symtab); if (rc == SEPOL_OK) { + if (orig->flavor == CIL_MACRO && data == NULL) { + /* Skipping macro re-declaration */ + if (args->orig_dest->flavor != CIL_BLOCKINHERIT) { + cil_log(CIL_ERR, " Re-declaration of macro is only allowed when inheriting a block\n"); + return SEPOL_ERR; + } + *finished = CIL_TREE_SKIP_HEAD; + return SEPOL_OK; + } + cil_tree_node_init(&new); new->parent = parent; @@ -2013,7 +2035,15 @@ int __cil_copy_node_helper(struct cil_tree_node *orig, __attribute__((unused)) u new->flavor = orig->flavor; new->data = data; - if (orig->flavor >= CIL_MIN_DECLARATIVE) { + if (orig->flavor == CIL_BLOCK && DATUM(data)->nodes->head != NULL) { + /* Duplicate block */ + if (args->orig_dest->flavor != CIL_BLOCKINHERIT) { + cil_log(CIL_ERR, " Re-declaration of block is only allowed when inheriting a block\n"); + rc = SEPOL_ERR; + goto exit; + } + cil_list_append(DATUM(new->data)->nodes, CIL_NODE, new); + } else if (orig->flavor >= CIL_MIN_DECLARATIVE) { /* Check the flavor of data if was found in the destination symtab */ if (DATUM(data)->nodes->head && FLAVOR(data) != orig->flavor) { cil_tree_log(orig, CIL_ERR, "Incompatible flavor when trying to copy %s", DATUM(data)->name); @@ -2098,12 +2128,13 @@ int cil_copy_ast(struct cil_db *db, struct cil_tree_node *orig, struct cil_tree_ int rc = SEPOL_ERR; struct cil_args_copy extra_args; + extra_args.orig_dest = dest; extra_args.dest = dest; extra_args.db = db; rc = cil_tree_walk(orig, __cil_copy_node_helper, NULL, __cil_copy_last_child_helper, &extra_args); if (rc != SEPOL_OK) { - cil_log(CIL_INFO, "cil_tree_walk failed, rc: %d\n", rc); + cil_tree_log(dest, CIL_ERR, "Failed to copy %s to %s", cil_node_to_string(orig), cil_node_to_string(dest)); goto exit; }
The commit d155b410d4bbc90d28f361b966f0429598da8188 (libsepol/cil: Check for duplicate blocks, optionals, and macros) added checks when copying blocks, macros, and optionals so that a duplicate would cause an exit with an error. Unfortunately, some policies exist that depend on this behavior when using inheritance. The behavior is as follows. For macros only the first declared macro matters. ; (macro m ((type ARG1)) (allow ARG1 self (CLASS (PERM1))) ) (block b (macro m ((type ARG1)) (allow ARG1 self (CLASS (PERM2))) ) ) (blockinherit b) (type t) (call m (t)) ; For this policy segment, the macro m in block b will not be called. Only the original macro m will be. This behavior has been used to override macros that are going to be inherited. Only the inherited macros that have not already been declared in the destination namespace will be used. Blocks seem to work fine even though there are two of them ; (block b1 (blockinherit b2) (block b (type t1) (allow t1 self (CLASS (PERM))) ) ) (block b2 (block b (type t2) (allow t2 self (CLASS (PERM))) ) ) (blockinherit b1) ; In this example, the blockinherit of b2 will cause there to be two block b's in block b1. Note that if both block b's tried to declare the same type, then that would be an error. The blockinherit of b1 will copy both block b's. This behavior has been used to allow the use of in-statements for a block that is being inherited. Since the in-statements are resolved before block inheritance, this only works if a block with the same name as the block to be inherited is declared in the namespace. To support the use of these two behaviors, allow duplicate blocks and macros when they occur as the result of block inheritance. In any other circumstances and error for a redeclaration will be given. Since the duplicate macro is not going to be used it is just skipped. The duplicate block will use the datum of the original block. In both cases a warning message will be produced (it will only be seen if "-v" is used when compiling the policy). Signed-off-by: James Carter <jwcart2@gmail.com> --- libsepol/cil/src/cil_copy_ast.c | 69 ++++++++++++++++++++++++--------- 1 file changed, 50 insertions(+), 19 deletions(-)