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Date: Thu, 27 Dec 2012 16:06:02 +0800
From: Chen Gang <gang.chen@...anux.com>
To: Theodore Ts'o <tytso@....edu>, adilger.kernel@...ger.ca
CC: akpm@...ux-foundation.org, jack@...e.cz, linux-ext4@...r.kernel.org
Subject: Re: [Suggestion] fs/ext3: memory leak by calling set_qf_name or clear_qf_name,
many times.
Really (just as Theodore Ts'o said), for ext4 is the same thing as ext3 !
so please help check it by ext4 maintainers, or ext3 maintainers
if want to let me to send relative patch, please tell me, I will try.
:-)
thanks.
gchen
于 2012年12月26日 13:04, Chen Gang 写道:
> Hello Theodore Ts'o
>
> in fs/ext3/supper.c
> for function set_qf_name:
> sbi->s_qf_names[qtype] may already have owned a memory (line 919..925)
> we set sbi->s_qf_names[qtype] = qname directly without checking (line 926)
>
> for function clear_qf_name:
> we set sbi->s_qf_names[qtype] = NULL (line 942..952)
>
>
> for function parse_options:
> we can call set_qf_name or clear_qf_name with USR or GRP many times.
> we find parameters not mind whether they are repeated. (line 975..985)
> so we may call set_qf_name or clear_qf_name several times.
> also may first call set_qf_name, then call clear_qf_name.
>
> in this situation, we will get memory leak.
>
> please help check this suggestion whether valid (I find it by code review).
>
>
> regards.
>
> gchen.
>
> 901 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
> 902 {
> 903 struct ext3_sb_info *sbi = EXT3_SB(sb);
> 904 char *qname;
> 905
> 906 if (sb_any_quota_loaded(sb) &&
> 907 !sbi->s_qf_names[qtype]) {
> 908 ext3_msg(sb, KERN_ERR,
> 909 "Cannot change journaled "
> 910 "quota options when quota turned on");
> 911 return 0;
> 912 }
> 913 qname = match_strdup(args);
> 914 if (!qname) {
> 915 ext3_msg(sb, KERN_ERR,
> 916 "Not enough memory for storing quotafile name");
> 917 return 0;
> 918 }
> 919 if (sbi->s_qf_names[qtype] &&
> 920 strcmp(sbi->s_qf_names[qtype], qname)) {
> 921 ext3_msg(sb, KERN_ERR,
> 922 "%s quota file already specified", QTYPE2NAME(qtype));
> 923 kfree(qname);
> 924 return 0;
> 925 }
> 926 sbi->s_qf_names[qtype] = qname;
> 927 if (strchr(sbi->s_qf_names[qtype], '/')) {
> 928 ext3_msg(sb, KERN_ERR,
> 929 "quotafile must be on filesystem root");
> 930 kfree(sbi->s_qf_names[qtype]);
> 931 sbi->s_qf_names[qtype] = NULL;
> 932 return 0;
> 933 }
> 934 set_opt(sbi->s_mount_opt, QUOTA);
> 935 return 1;
> 936 }
> 937
> 938 static int clear_qf_name(struct super_block *sb, int qtype) {
> 939
> 940 struct ext3_sb_info *sbi = EXT3_SB(sb);
> 941
> 942 if (sb_any_quota_loaded(sb) &&
> 943 sbi->s_qf_names[qtype]) {
> 944 ext3_msg(sb, KERN_ERR, "Cannot change journaled quota options"
> 945 " when quota turned on");
> 946 return 0;
> 947 }
> 948 /*
> 949 * The space will be released later when all options are confirmed
> 950 * to be correct
> 951 */
> 952 sbi->s_qf_names[qtype] = NULL;
> 953 return 1;
> 954 }
> 955 #endif
> 956
> 957 static int parse_options (char *options, struct super_block *sb,
> 958 unsigned int *inum, unsigned long *journal_devnum,
> 959 ext3_fsblk_t *n_blocks_count, int is_remount)
> 960 {
> 961 struct ext3_sb_info *sbi = EXT3_SB(sb);
> 962 char * p;
> 963 substring_t args[MAX_OPT_ARGS];
> 964 int data_opt = 0;
> 965 int option;
> 966 kuid_t uid;
> 967 kgid_t gid;
> 968 #ifdef CONFIG_QUOTA
> 969 int qfmt;
> 970 #endif
> 971
> 972 if (!options)
> 973 return 1;
> 974
> 975 while ((p = strsep (&options, ",")) != NULL) {
> 976 int token;
> 977 if (!*p)
> 978 continue;
> 979 /*
> 980 * Initialize args struct so we know whether arg was
> 981 * found; some options take optional arguments.
> 982 */
> 983 args[0].to = args[0].from = NULL;
> 984 token = match_token(p, tokens, args);
> 985 switch (token) {
> 986 case Opt_bsd_df:
> 987 clear_opt (sbi->s_mount_opt, MINIX_DF);
> 988 break;
> 989 case Opt_minix_df:
> 990 set_opt (sbi->s_mount_opt, MINIX_DF);
> 991 break;
> 992 case Opt_grpid:
> 993 set_opt (sbi->s_mount_opt, GRPID);
> 955 #endif
> 956
> 957 static int parse_options (char *options, struct super_block *sb,
> 958 unsigned int *inum, unsigned long *journal_devnum,
> 959 ext3_fsblk_t *n_blocks_count, int is_remount)
> 960 {
> 961 struct ext3_sb_info *sbi = EXT3_SB(sb);
> 962 char * p;
> 963 substring_t args[MAX_OPT_ARGS];
> 964 int data_opt = 0;
> 965 int option;
> 966 kuid_t uid;
> 967 kgid_t gid;
> 968 #ifdef CONFIG_QUOTA
> 969 int qfmt;
> 970 #endif
> 971
> 972 if (!options)
> 973 return 1;
> 974
> 975 while ((p = strsep (&options, ",")) != NULL) {
> 976 int token;
> 977 if (!*p)
> 978 continue;
> 979 /*
> 980 * Initialize args struct so we know whether arg was
> 981 * found; some options take optional arguments.
> 982 */
> 983 args[0].to = args[0].from = NULL;
> 984 token = match_token(p, tokens, args);
> 985 switch (token) {
> 986 case Opt_bsd_df:
> 987 clear_opt (sbi->s_mount_opt, MINIX_DF);
> 988 break;
> 989 case Opt_minix_df:
> 990 set_opt (sbi->s_mount_opt, MINIX_DF);
> 991 break;
> 992 case Opt_grpid:
> 993 set_opt (sbi->s_mount_opt, GRPID);
> 994 break;
> 995 case Opt_nogrpid:
> 996 clear_opt (sbi->s_mount_opt, GRPID);
> 997 break;
> 998 case Opt_resuid:
> 999 if (match_int(&args[0], &option))
> 1000 return 0;
> 1001 uid = make_kuid(current_user_ns(), option);
> 1002 if (!uid_valid(uid)) {
> 1003 ext3_msg(sb, KERN_ERR, "Invalid uid value %d", option);
> 1004 return 0;
> 1005
> 1006 }
> 1007 sbi->s_resuid = uid;
> 1008 break;
> 1009 case Opt_resgid:
> 1010 if (match_int(&args[0], &option))
> 1011 return 0;
> 1012 gid = make_kgid(current_user_ns(), option);
> 1013 if (!gid_valid(gid)) {
> 1014 ext3_msg(sb, KERN_ERR, "Invalid gid value %d", option);
> 1015 return 0;
> 1016 }
> 1017 sbi->s_resgid = gid;
> 1018 break;
> 1019 case Opt_sb:
> 1020 /* handled by get_sb_block() instead of here */
> 1021 /* *sb_block = match_int(&args[0]); */
> 1022 break;
> 1023 case Opt_err_panic:
> 1024 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
> 1025 clear_opt (sbi->s_mount_opt, ERRORS_RO);
> 1026 set_opt (sbi->s_mount_opt, ERRORS_PANIC);
> 1027 break;
> 1028 case Opt_err_ro:
> 1029 clear_opt (sbi->s_mount_opt, ERRORS_CONT);
> 1030 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
> 1031 set_opt (sbi->s_mount_opt, ERRORS_RO);
> 1032 break;
> 1033 case Opt_err_cont:
> 1034 clear_opt (sbi->s_mount_opt, ERRORS_RO);
> 1035 clear_opt (sbi->s_mount_opt, ERRORS_PANIC);
> 1036 set_opt (sbi->s_mount_opt, ERRORS_CONT);
> 1037 break;
> 1038 case Opt_nouid32:
> 1039 set_opt (sbi->s_mount_opt, NO_UID32);
> 1040 break;
> 1041 case Opt_nocheck:
> 1042 clear_opt (sbi->s_mount_opt, CHECK);
> 1043 break;
> 1044 case Opt_debug:
> 1045 set_opt (sbi->s_mount_opt, DEBUG);
> 1046 break;
> 1047 case Opt_oldalloc:
> 1048 ext3_msg(sb, KERN_WARNING,
> 1049 "Ignoring deprecated oldalloc option");
> 1050 break;
> 1051 case Opt_orlov:
> 1052 ext3_msg(sb, KERN_WARNING,
> 1053 "Ignoring deprecated orlov option");
> 1054 break;
> 1055 #ifdef CONFIG_EXT3_FS_XATTR
> 1056 case Opt_user_xattr:
> 1057 set_opt (sbi->s_mount_opt, XATTR_USER);
> 1058 break;
> 1059 case Opt_nouser_xattr:
> 1060 clear_opt (sbi->s_mount_opt, XATTR_USER);
> 1061 break;
> 1062 #else
> 1063 case Opt_user_xattr:
> 1064 case Opt_nouser_xattr:
> 1065 ext3_msg(sb, KERN_INFO,
> 1066 "(no)user_xattr options not supported");
> 1067 break;
> 1068 #endif
> 1069 #ifdef CONFIG_EXT3_FS_POSIX_ACL
> 1070 case Opt_acl:
> 1071 set_opt(sbi->s_mount_opt, POSIX_ACL);
> 1072 break;
> 1073 case Opt_noacl:
> 1074 clear_opt(sbi->s_mount_opt, POSIX_ACL);
> 1075 break;
> 1076 #else
> 1077 case Opt_acl:
> 1078 case Opt_noacl:
> 1079 ext3_msg(sb, KERN_INFO,
> 1080 "(no)acl options not supported");
> 1081 break;
> 1082 #endif
> 1083 case Opt_reservation:
> 1084 set_opt(sbi->s_mount_opt, RESERVATION);
> 1085 break;
> 1086 case Opt_noreservation:
> 1087 clear_opt(sbi->s_mount_opt, RESERVATION);
> 1088 break;
> 1089 case Opt_journal_update:
> 1090 /* @@@ FIXME */
> 1091 /* Eventually we will want to be able to create
> 1092 a journal file here. For now, only allow the
> 1093 user to specify an existing inode to be the
> 1094 journal file. */
> 1095 if (is_remount) {
> 1096 ext3_msg(sb, KERN_ERR, "error: cannot specify "
> 1097 "journal on remount");
> 1098 return 0;
> 1099 }
> 1100 set_opt (sbi->s_mount_opt, UPDATE_JOURNAL);
> 1101 break;
> 1102 case Opt_journal_inum:
> 1103 if (is_remount) {
> 1104 ext3_msg(sb, KERN_ERR, "error: cannot specify "
> 1105 "journal on remount");
> 1106 return 0;
> 1107 }
> 1108 if (match_int(&args[0], &option))
> 1109 return 0;
> 1110 *inum = option;
> 1111 break;
> 1112 case Opt_journal_dev:
> 1113 if (is_remount) {
> 1114 ext3_msg(sb, KERN_ERR, "error: cannot specify "
> 1115 "journal on remount");
> 1116 return 0;
> 1117 }
> 1118 if (match_int(&args[0], &option))
> 1119 return 0;
> 1120 *journal_devnum = option;
> 1121 break;
> 1122 case Opt_noload:
> 1123 set_opt (sbi->s_mount_opt, NOLOAD);
> 1124 break;
> 1125 case Opt_commit:
> 1126 if (match_int(&args[0], &option))
> 1127 return 0;
> 1128 if (option < 0)
> 1129 return 0;
> 1130 if (option == 0)
> 1131 option = JBD_DEFAULT_MAX_COMMIT_AGE;
> 1132 sbi->s_commit_interval = HZ * option;
> 1133 break;
> 1134 case Opt_data_journal:
> 1135 data_opt = EXT3_MOUNT_JOURNAL_DATA;
> 1136 goto datacheck;
> 1137 case Opt_data_ordered:
> 1138 data_opt = EXT3_MOUNT_ORDERED_DATA;
> 1139 goto datacheck;
> 1140 case Opt_data_writeback:
> 1141 data_opt = EXT3_MOUNT_WRITEBACK_DATA;
> 1142 datacheck:
> 1143 if (is_remount) {
> 1144 if (test_opt(sb, DATA_FLAGS) == data_opt)
> 1145 break;
> 1146 ext3_msg(sb, KERN_ERR,
> 1147 "error: cannot change "
> 1148 "data mode on remount. The filesystem "
> 1149 "is mounted in data=%s mode and you "
> 1150 "try to remount it in data=%s mode.",
> 1151 data_mode_string(test_opt(sb,
> 1152 DATA_FLAGS)),
> 1153 data_mode_string(data_opt));
> 1154 return 0;
> 1155 } else {
> 1156 clear_opt(sbi->s_mount_opt, DATA_FLAGS);
> 1157 sbi->s_mount_opt |= data_opt;
> 1158 }
> 1159 break;
> 1160 case Opt_data_err_abort:
> 1161 set_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
> 1162 break;
> 1163 case Opt_data_err_ignore:
> 1164 clear_opt(sbi->s_mount_opt, DATA_ERR_ABORT);
> 1165 break;
> 1166 #ifdef CONFIG_QUOTA
> 1167 case Opt_usrjquota:
> 1168 if (!set_qf_name(sb, USRQUOTA, &args[0]))
> 1169 return 0;
> 1170 break;
> 1171 case Opt_grpjquota:
> 1172 if (!set_qf_name(sb, GRPQUOTA, &args[0]))
> 1173 return 0;
> 1174 break;
> 1175 case Opt_offusrjquota:
> 1176 if (!clear_qf_name(sb, USRQUOTA))
> 1177 return 0;
> 1178 break;
> 1179 case Opt_offgrpjquota:
> 1180 if (!clear_qf_name(sb, GRPQUOTA))
> 1181 return 0;
> 1182 break;
>
--
Chen Gang
Asianux Corporation
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