From e201139be17e525c266240acf762c2b6a9fe6436 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Mon, 7 Nov 2022 13:35:44 +0900 Subject: [PATCH v17 2/3] Invent open_auth_file() in hba.c, to refactor auth file opening This adds a check on the recursion depth when including auth files, something that has never been done when processing '@' files for database and user name lists in pg_hba.conf. --- src/include/libpq/hba.h | 4 +- src/backend/libpq/hba.c | 100 ++++++++++++++++++++++--------- src/backend/utils/adt/hbafuncs.c | 18 ++---- 3 files changed, 79 insertions(+), 43 deletions(-) diff --git a/src/include/libpq/hba.h b/src/include/libpq/hba.h index 7ad227d34a..a84a5f0961 100644 --- a/src/include/libpq/hba.h +++ b/src/include/libpq/hba.h @@ -177,7 +177,9 @@ extern int check_usermap(const char *usermap_name, extern HbaLine *parse_hba_line(TokenizedAuthLine *tok_line, int elevel); extern IdentLine *parse_ident_line(TokenizedAuthLine *tok_line, int elevel); extern bool pg_isblank(const char c); +extern FILE *open_auth_file(const char *filename, int elevel, int depth, + char **err_msg); extern MemoryContext tokenize_auth_file(const char *filename, FILE *file, - List **tok_lines, int elevel); + List **tok_lines, int elevel, int depth); #endif /* HBA_H */ diff --git a/src/backend/libpq/hba.c b/src/backend/libpq/hba.c index a9f87ab5bf..d8c0b585e5 100644 --- a/src/backend/libpq/hba.c +++ b/src/backend/libpq/hba.c @@ -117,7 +117,8 @@ static const char *const UserAuthName[] = static List *tokenize_inc_file(List *tokens, const char *outer_filename, - const char *inc_filename, int elevel, char **err_msg); + const char *inc_filename, int elevel, + int depth, char **err_msg); static bool parse_hba_auth_opt(char *name, char *val, HbaLine *hbaline, int elevel, char **err_msg); static int regcomp_auth_token(AuthToken *token, char *filename, int line_num, @@ -414,7 +415,7 @@ regexec_auth_token(const char *match, AuthToken *token, size_t nmatch, */ static List * next_field_expand(const char *filename, char **lineptr, - int elevel, char **err_msg) + int elevel, int depth, char **err_msg) { char buf[MAX_TOKEN]; bool trailing_comma; @@ -431,7 +432,7 @@ next_field_expand(const char *filename, char **lineptr, /* Is this referencing a file? */ if (!initial_quote && buf[0] == '@' && buf[1] != '\0') tokens = tokenize_inc_file(tokens, filename, buf + 1, - elevel, err_msg); + elevel, depth + 1, err_msg); else tokens = lappend(tokens, make_auth_token(buf, initial_quote)); } while (trailing_comma && (*err_msg == NULL)); @@ -459,6 +460,7 @@ tokenize_inc_file(List *tokens, const char *outer_filename, const char *inc_filename, int elevel, + int depth, char **err_msg) { char *inc_fullname; @@ -468,24 +470,18 @@ tokenize_inc_file(List *tokens, MemoryContext linecxt; inc_fullname = AbsoluteConfigLocation(inc_filename, outer_filename); + inc_file = open_auth_file(inc_fullname, elevel, depth, err_msg); - inc_file = AllocateFile(inc_fullname, "r"); if (inc_file == NULL) { - int save_errno = errno; - - ereport(elevel, - (errcode_for_file_access(), - errmsg("could not open secondary authentication file \"@%s\" as \"%s\": %m", - inc_filename, inc_fullname))); - *err_msg = psprintf("could not open secondary authentication file \"@%s\" as \"%s\": %s", - inc_filename, inc_fullname, strerror(save_errno)); + /* error already logged */ pfree(inc_fullname); return tokens; } /* There is possible recursion here if the file contains @ */ - linecxt = tokenize_auth_file(inc_fullname, inc_file, &inc_lines, elevel); + linecxt = tokenize_auth_file(inc_fullname, inc_file, &inc_lines, elevel, + depth); FreeFile(inc_file); pfree(inc_fullname); @@ -521,6 +517,59 @@ tokenize_inc_file(List *tokens, return tokens; } +/* + * open_auth_file + * Open the given file. + * + * filename: the absolute path to the target file + * elevel: message logging level + * depth: recursion level of the file opened. + * err_msg: details about the error. + * + * Return value is the opened file. On error, returns NULL with details + * about the error stored in "err_msg". + */ +FILE * +open_auth_file(const char *filename, int elevel, int depth, + char **err_msg) +{ + FILE *file; + + /* + * Reject too-deep include nesting depth. This is just a safety check to + * avoid dumping core due to stack overflow if an include file loops back + * to itself. The maximum nesting depth is pretty arbitrary. + */ + if (depth > 10) + { + ereport(elevel, + (errcode_for_file_access(), + errmsg("could not open file \"%s\": maximum nesting depth exceeded", + filename))); + if (err_msg) + *err_msg = psprintf("could not open file \"%s\": maximum nesting depth exceeded", + filename); + return NULL; + } + + file = AllocateFile(filename, "r"); + if (file == NULL) + { + int save_errno = errno; + + ereport(elevel, + (errcode_for_file_access(), + errmsg("could not open file \"%s\": %m", + filename))); + if (err_msg) + *err_msg = psprintf("could not open file \"%s\": %s", + filename, strerror(save_errno)); + return NULL; + } + + return file; +} + /* * tokenize_auth_file * Tokenize the given file. @@ -532,6 +581,7 @@ tokenize_inc_file(List *tokens, * file: the already-opened target file * tok_lines: receives output list * elevel: message logging level + * depth: level of recursion when tokenizing the target file * * Errors are reported by logging messages at ereport level elevel and by * adding TokenizedAuthLine structs containing non-null err_msg fields to the @@ -542,7 +592,7 @@ tokenize_inc_file(List *tokens, */ MemoryContext tokenize_auth_file(const char *filename, FILE *file, List **tok_lines, - int elevel) + int elevel, int depth) { int line_number = 1; StringInfoData buf; @@ -613,7 +663,7 @@ tokenize_auth_file(const char *filename, FILE *file, List **tok_lines, List *current_field; current_field = next_field_expand(filename, &lineptr, - elevel, &err_msg); + elevel, depth, &err_msg); /* add field to line, unless we are at EOL or comment start */ if (current_field != NIL) current_line = lappend(current_line, current_field); @@ -2332,17 +2382,14 @@ load_hba(void) MemoryContext oldcxt; MemoryContext hbacxt; - file = AllocateFile(HbaFileName, "r"); + file = open_auth_file(HbaFileName, LOG, 0, NULL); if (file == NULL) { - ereport(LOG, - (errcode_for_file_access(), - errmsg("could not open configuration file \"%s\": %m", - HbaFileName))); + /* error already logged */ return false; } - linecxt = tokenize_auth_file(HbaFileName, file, &hba_lines, LOG); + linecxt = tokenize_auth_file(HbaFileName, file, &hba_lines, LOG, 0); FreeFile(file); /* Now parse all the lines */ @@ -2703,18 +2750,15 @@ load_ident(void) MemoryContext ident_context; IdentLine *newline; - file = AllocateFile(IdentFileName, "r"); + /* not FATAL ... we just won't do any special ident maps */ + file = open_auth_file(IdentFileName, LOG, 0, NULL); if (file == NULL) { - /* not fatal ... we just won't do any special ident maps */ - ereport(LOG, - (errcode_for_file_access(), - errmsg("could not open usermap file \"%s\": %m", - IdentFileName))); + /* error already logged */ return false; } - linecxt = tokenize_auth_file(IdentFileName, file, &ident_lines, LOG); + linecxt = tokenize_auth_file(IdentFileName, file, &ident_lines, LOG, 0); FreeFile(file); /* Now parse all the lines */ diff --git a/src/backend/utils/adt/hbafuncs.c b/src/backend/utils/adt/hbafuncs.c index e12ff8ca72..b662e7b55f 100644 --- a/src/backend/utils/adt/hbafuncs.c +++ b/src/backend/utils/adt/hbafuncs.c @@ -380,14 +380,9 @@ fill_hba_view(Tuplestorestate *tuple_store, TupleDesc tupdesc) * (Most other error conditions should result in a message in a view * entry.) */ - file = AllocateFile(HbaFileName, "r"); - if (file == NULL) - ereport(ERROR, - (errcode_for_file_access(), - errmsg("could not open configuration file \"%s\": %m", - HbaFileName))); + file = open_auth_file(HbaFileName, ERROR, 0, NULL); - linecxt = tokenize_auth_file(HbaFileName, file, &hba_lines, DEBUG3); + linecxt = tokenize_auth_file(HbaFileName, file, &hba_lines, DEBUG3, 0); FreeFile(file); /* Now parse all the lines */ @@ -529,14 +524,9 @@ fill_ident_view(Tuplestorestate *tuple_store, TupleDesc tupdesc) * (Most other error conditions should result in a message in a view * entry.) */ - file = AllocateFile(IdentFileName, "r"); - if (file == NULL) - ereport(ERROR, - (errcode_for_file_access(), - errmsg("could not open usermap file \"%s\": %m", - IdentFileName))); + file = open_auth_file(IdentFileName, ERROR, 0, NULL); - linecxt = tokenize_auth_file(IdentFileName, file, &ident_lines, DEBUG3); + linecxt = tokenize_auth_file(IdentFileName, file, &ident_lines, DEBUG3, 0); FreeFile(file); /* Now parse all the lines */ -- 2.38.1