libpwdgrp: fix a memory leak in getXXnam (we did not save address of string buf)
function old new delta convert_to_struct 261 269 +8 const_sp_db 20 24 +4 const_pw_db 20 24 +4 const_gr_db 20 24 +4 tokenize 144 147 +3 parse_common 185 188 +3 get_S 82 85 +3 bb_internal_getpwent_r 188 185 -3 gr_off 4 - -4 getXXnam 171 165 -6 pw_off 7 - -7 getgrouplist_internal 237 229 -8 getXXnam_r 215 207 -8 sp_off 9 - -9 ------------------------------------------------------------------------------ (add/remove: 0/3 grow/shrink: 7/4 up/down: 29/-45) Total: -16 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
31d6734457
commit
8d547aca75
@ -32,6 +32,27 @@
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#include "libbb.h"
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struct const_passdb {
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const char *filename;
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const char def[10];
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const uint8_t off[9];
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uint8_t numfields;
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};
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struct passdb {
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const char *filename;
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const char def[10];
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const uint8_t off[9];
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uint8_t numfields;
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FILE *fp;
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char *malloced;
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char struct_result[0
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| sizeof(struct passwd)
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| sizeof(struct group)
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IF_USE_BB_SHADOW( | sizeof(struct spwd) )
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/* bitwise OR above is poor man's max(a,b,c) */
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];
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};
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/* S = string not empty, s = string maybe empty,
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* I = uid,gid, l = long maybe empty, m = members,
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* r = reserved
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@ -40,7 +61,9 @@
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#define GR_DEF "SsIm"
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#define SP_DEF "Ssllllllr"
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static const uint8_t pw_off[] ALIGN1 = {
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static const struct const_passdb const_pw_db = {
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_PATH_PASSWD, PW_DEF,
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{
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offsetof(struct passwd, pw_name), /* 0 S */
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offsetof(struct passwd, pw_passwd), /* 1 s */
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offsetof(struct passwd, pw_uid), /* 2 I */
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@ -48,15 +71,23 @@ static const uint8_t pw_off[] ALIGN1 = {
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offsetof(struct passwd, pw_gecos), /* 4 s */
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offsetof(struct passwd, pw_dir), /* 5 S */
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offsetof(struct passwd, pw_shell) /* 6 S */
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},
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sizeof(PW_DEF)-1
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};
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static const uint8_t gr_off[] ALIGN1 = {
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static const struct const_passdb const_gr_db = {
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_PATH_GROUP, GR_DEF,
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{
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offsetof(struct group, gr_name), /* 0 S */
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offsetof(struct group, gr_passwd), /* 1 s */
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offsetof(struct group, gr_gid), /* 2 I */
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offsetof(struct group, gr_mem) /* 3 m (char **) */
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},
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sizeof(GR_DEF)-1
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};
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#if ENABLE_USE_BB_SHADOW
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static const uint8_t sp_off[] ALIGN1 = {
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static const struct const_passdb const_sp_db = {
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_PATH_SHADOW, SP_DEF,
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{
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offsetof(struct spwd, sp_namp), /* 0 S Login name */
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offsetof(struct spwd, sp_pwdp), /* 1 s Encrypted password */
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offsetof(struct spwd, sp_lstchg), /* 2 l */
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@ -66,35 +97,14 @@ static const uint8_t sp_off[] ALIGN1 = {
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offsetof(struct spwd, sp_inact), /* 6 l */
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offsetof(struct spwd, sp_expire), /* 7 l */
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offsetof(struct spwd, sp_flag) /* 8 r Reserved */
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},
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sizeof(SP_DEF)-1
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};
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#endif
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struct const_passdb {
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const char *filename;
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const uint8_t *off;
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const char def[10];
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uint8_t numfields;
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uint8_t size_of;
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};
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struct passdb {
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const char *filename;
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const uint8_t *off;
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const char def[10];
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uint8_t numfields;
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uint8_t size_of;
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FILE *fp;
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void *malloced;
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};
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static const struct const_passdb const_pw_db = { _PATH_PASSWD, pw_off, PW_DEF, sizeof(PW_DEF)-1, sizeof(struct passwd) };
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static const struct const_passdb const_gr_db = { _PATH_GROUP , gr_off, GR_DEF, sizeof(GR_DEF)-1, sizeof(struct group) };
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#if ENABLE_USE_BB_SHADOW
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static const struct const_passdb const_sp_db = { _PATH_SHADOW, sp_off, SP_DEF, sizeof(SP_DEF)-1, sizeof(struct spwd) };
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#endif
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/* We avoid having big global data. */
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struct statics {
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/* It's ok to use same buffer (db[0].malloced) for getpwuid and getpwnam.
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/* It's ok to use same buffer (db[0].struct_result) for getpwuid and getpwnam.
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* Manpage says:
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* "The return value may point to a static area, and may be overwritten
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* by subsequent calls to getpwent(), getpwnam(), or getpwuid()."
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@ -223,9 +233,15 @@ static char *parse_file(const char *filename,
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}
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/* Convert passwd/group/shadow file record in buffer to a struct */
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static void *convert_to_struct(const char *def, const unsigned char *off,
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static void *convert_to_struct(struct passdb *db,
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char *buffer, void *result)
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{
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const char *def = db->def;
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const uint8_t *off = db->off;
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/* TODO? for consistency, zero out all fields */
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/* memset(result, 0, size_of_result);*/
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for (;;) {
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void *member = (char*)result + (*off++);
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@ -282,7 +298,8 @@ static void *convert_to_struct(const char *def, const unsigned char *off,
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/****** getXXnam/id_r */
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static int FAST_FUNC getXXnam_r(const char *name, uintptr_t db_and_field_pos, char *buffer, size_t buflen,
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static int FAST_FUNC getXXnam_r(const char *name, uintptr_t db_and_field_pos,
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char *buffer, size_t buflen,
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void *result)
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{
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void *struct_buf = *(void**)result;
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@ -299,7 +316,7 @@ static int FAST_FUNC getXXnam_r(const char *name, uintptr_t db_and_field_pos, ch
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errno = ERANGE;
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} else {
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memcpy(buffer, buf, size);
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*(void**)result = convert_to_struct(db->def, db->off, buffer, struct_buf);
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*(void**)result = convert_to_struct(db, buffer, struct_buf);
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}
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free(buf);
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}
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@ -310,7 +327,8 @@ static int FAST_FUNC getXXnam_r(const char *name, uintptr_t db_and_field_pos, ch
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return errno;
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}
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int FAST_FUNC getpwnam_r(const char *name, struct passwd *struct_buf, char *buffer, size_t buflen,
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int FAST_FUNC getpwnam_r(const char *name, struct passwd *struct_buf,
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char *buffer, size_t buflen,
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struct passwd **result)
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{
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/* Why the "store buffer address in result" trick?
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@ -357,7 +375,7 @@ static int FAST_FUNC getXXent_r(void *struct_buf, char *buffer, size_t buflen,
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errno = ERANGE;
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} else {
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memcpy(buffer, buf, size);
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*(void**)result = convert_to_struct(db->def, db->off, buffer, struct_buf);
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*(void**)result = convert_to_struct(db, buffer, struct_buf);
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}
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free(buf);
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}
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@ -393,12 +411,11 @@ static void* FAST_FUNC getXXnam(const char *name, unsigned db_and_field_pos)
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close_on_exec_on(fileno(db->fp));
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}
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free(db->malloced);
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db->malloced = NULL;
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buf = parse_common(db->fp, db->filename, db->numfields, name, db_and_field_pos & 3);
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if (buf) {
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db->malloced = xzalloc(db->size_of);
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result = convert_to_struct(db->def, db->off, buf, db->malloced);
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free(db->malloced);
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db->malloced = buf;
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result = convert_to_struct(db, buf, db->struct_result);
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}
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return result;
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}
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@ -465,7 +482,7 @@ static gid_t* FAST_FUNC getgrouplist_internal(int *ngroups_ptr,
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while ((buf = parse_common(fp, _PATH_GROUP, sizeof(GR_DEF)-1, NULL, 0)) != NULL) {
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char **m;
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struct group group;
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if (!convert_to_struct(GR_DEF, gr_off, buf, &group))
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if (!convert_to_struct(&S.db[1], buf, &group))
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goto next;
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if (group.gr_gid == gid)
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goto next;
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